363.7 C8692 2001 ^^ K^^^B^ ^B^^H lU in / I, Illinois Ecosystems .(.. li'l^ '^ IFW J^- ■ ^Ji'T'' ,' '• ' '4 •S-J, fi'y'i'ilCtlMft iilL ...Hill 1\ i tor' " j?-'*'^^ ITT ^1 J rt^l:; ^^■' ibf""^ ■'nj ^,' C:a'>.\- i- m M ^•'-: .^i Mji Illinois Department of Natural Resources i . 5« ■ t - f UmVBISITYOF UUNCNS UBRAITV ■MT.HSr.SUifV. NOTICE: Return or renew all Library Materials) The Minimum Fee lor each Lost Book it $50.00. The person charging this material is responsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Ttieft, mutilation, and underlining of books are reasons for discipli- nary action and may result in dismissal from the Univeraity. To renew call Telephone Center, 333-8400 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN jano NOV 1 3 200E AUG 2 7 2007 6 2003 LI6I— O-I096 Natural History Survey LibiTdJcy Critical Trends in Illinois Ecosystems Critical Trends Assessment Program February 2001 Illinois Department of Natural Resources Office of Realty and Environmental Planning in collaboration with Office of Scientific Research and Analysis Natural History Survey Division ■:"i?M'.^':i ^>' ■■ -''■■ George H. RyanJ (governor State of Illinois Brent Manning, Director Illinois Department of Natural Resources 524 South Second Street Springfield, Illinois 62701 SM/PRT 3201 144 Printed by the autliorily of tlic State of Illinois Printed with soy ink on recycled and recyclable paper Equal opportunity to participate in programs of the Illinois Department of Natural Resources (IDNR) and those funded b> the U.S. Fish and Wildlife Service and other agencies is available to all individuals regardless of race, sex, national origin, disability-. age, religion or other non-merit factors. If you believe you have been discriminated against, contact the funding source's ci\nll rights office and/or the Equal Employment Opportunity' Officer, IDNR, S24 S. Second. Springfield, 111. 62"01-1~87; iiy/TSS-OOG?;!!^' 217/782-9173. This information may be provided in an alternative format if required. Contact the DNR Clearinghouse at 217/782-7498 for assistance. Table Of Contents m Table of Contents Chapter 1 . Summary 1 Landcover Mapping 1 Resource Rich Areas 2 Regional Assessments 2 Ecosystem Monitoring 5 PLAN-IT EARTH 7 Chapter 2. Statewide Land Cover 8 Cropland 8 Grassland 8 Forest/Woodland 8 Wetland 10 Urban/Built-Up Land 10 Open Water 10 Barren/Exposed Land 10 Chapter 3. Ecosystem Monitoring Results 11 Forests 12 Grasslands 19 Wetlands 22 Streams 26 Correlating Aquatic Indicators 36 Chapter 4. Rock River Watershed 38 Ecosystem Monitoring 39 Regional Assessments Upper Rock River Basin 40 Lower Rock River Basin 42 Kishwaukee River Basin 44 Sugar-Pecatonica Rivers Basin 46 Driftless Area 48 Chapter 5. Fox and Des Plaines Rivers Watershed 51 Ecosystem Monitoring 52 Regional Assessments Fox River Basin 54 Upper Des Plaines River Basin 56 Chapter 6. Kankakee, Vermilion and Mackinaw Rivers Watershed 59 Ecosystem Monitoring 59 Regional Assessments Kankakee River Valley 62 Mackinaw River Basin 64 Chapter 7. Spoon River Watershed 67 Ecosystem Monitoring 67 Regional Assessments Spoon River Basin 68 Illinois River Bluffs 70 rv Critical Trends in Illinois Ecosystems Chapter 8. Sangamon River Watershed 73 Ecosystem Monitoring 73 Chapter 9. LaMoine River Watershed 76 Ecosystem Monitoring 76 Regional Assessments Big Rivers 78 Chapter 10. Kaskaskja River Watershed 81 Ecosystem Monitoring 82 Regional Assessments Sinkhole Plain 83 Chapter 1 1 . Embarras and Vermilion Rivers Watershed 87 Ecosystem Monitoring 88 Regional Assessments Embarras River Basin 89 Illinois Headwaters 91 Chapter 12. Little Wabash River Watershed 95 Ecosystem Monitoring 96 Chapter 13. Big Muddy, Saline and Cache Rtvers Watershed 97 Ecosystem Monitoring 98 Regional Assessments Cache River Basin 100 UST OF FIGURES Chapter 1 . Summary Figure 1 . Resource rich areas 3 Figure 2. Assessment areas 4 Chapter 2. Statewide Land Cover Figure 3- Statewide land cover percentages 8 Figure 4. Statewide land cover 9 Chapter 3. Ecosystem Monitoring Results Figure 5. CTAP forest monitoring sites, 1997-1999 13 Figure 6. ForestWatch monitoring sites, 1998-1999 14 Figure 7. Most abundant species, ForestWatch 15 Figure 8. Species with the greatest basal area, ForestWatch 15 Figure 9. Number of invasive and non-invasive shrub and vine stems found at 52 ForestWatch sites 17 Figure 10. The percentage of non-native plants at CTAP forest sites, by layer and region. ... 17 Figure 11. Maple takeover at Fern Trail Forest 18 Figure 12. The relationship between forest bird diversity' and the amount of forest in the surrounding landscape 19 Figure 13. CTAP grassland monitoring sites, 1997-1999 20 Figure 14. The percentage of non-native plants at CTAP grassland sites, by layer and region . 21 Figure 15. CTAP wetland monitoring sites, 1997-1999 23 Figure 16. The percentage of non-native plants at CTAP wethmd sites, by layer and region . . 24 Figure 17. CTAP stream monitoring sites, 1997-1999 27 Figure 18. RiverWatch monitoring sites, 1995-1999 28 Figure 19. ISIS watersheds 29 Table Of Contents Figure 20. Distribution of average habitat quality scores statewide and for 10 ISIS watersheds 31 Figure 21. Distribution of average EPT taxa richness statewide and for 10 ISIS watersheds. . 31 Figure 22. Distribution of EPT taxa richness, RiverWatch 31 Figure 23. Distribution of total taxa richness, RiverWatch 32 Figure 24. Distribution of average HBI scores statewide and for 10 ISIS watersheds 32 Figure 25. Most common macroinvertebrates sampled by RiverWatch 33 Figure 26. Distribution of average native fish species richness statewide and for 10 ISIS watersheds 34 Figure 27. The relative proportion of the three most abundant species sampled in each of seven IDNR Fisheries watersheds and CTAP statewide average 34 Figure 28. Percentage of exotic species at seven IDNR Fisheries basins and the CTAP statewide average 35 Chapter 4. Rock Rtver Watershed Figure 29. Monitoring sites 39 Figure 30. Upper Rock River basin land cover 40 Figure 3 1 • Lower Rock River basin land cover 42 Figure 32. Kishwaukee River basin land cover 45 Figure 33. Sugar-Pecatonica rivers basin land cover 47 Figure 34. Driftless Area land cover 49 Chapter 5. Fox and Des Plaines Rivers Watershed Figure 35. Monitoring sites 52 Figure 36. Maple takeover in an oak-hickory forest 53 Figure 37. Number of invasive and non-invasive shrub and vine stems 54 Figure 38. Fox River basin land cover 54 Figure 39. Upper Des Plaines River basin land cover 57 Chapter 6. Kankakee, Vermilion and Mackinaw Rivers Watershed Figure 40. Monitoring sites 60 Figure 41. Number of invasive and non-invasive shrub and vine stems 61 Figure 42. Kankakee River valley land cover 62 Figure 43. Mackinaw River basin land cover 65 Chapter 7. Spoon River Watershed Figure 44. Monitoring sites 68 Figure 45. Spoon River basin land cover 69 Figure 46. Illinois River Bluffs land cover 71 C^HAinER 8. SaNOAMON RiVER WATERSHED Figure 47. Monitoring sites 74 Chapter 9. LaMoine River Watershed Figure 48. Monitoring sites 77 Figure 49. Number of invasive and non-invasive shrub and vine stems 78 Figure 50. Big Rivers land cover 79 (JiAPTER 10. Kaskaskia River Water.shed Figure 51. Monitoring sites 82 Figure 52. Number of invasive and non-invasive shrub and vine stems 83 Figure 53 Sinkhole Plain land cover 84 ClIAn EK 1 I . FviliAKRAS AND VERMII.ION RIVERS WaTERSIIED figure 54. Monitoring .sites 88 Figure 55. Number of invasive and non-invasive shrub and vine stems 89 ligure 56. Embarr.is Ri%er basin land cover 90 Figure 57. Illinois Headwaters land cover 92 VI Critical Trends in Illinois Ecosystems Chapter 12. Little Wabash River Watershed Figure 58. Monitoring sites 96 Chapter 13. Big Muddy, Saline and Cache Rivers Watershed Figure 59. Monitoring sites 98 Figure 60. Maple takeover in an oak-hickory forest 99 Figure 61. Number of invasive and non-invasive shrub and vine stems 100 Figure 62. Cache River basin land cover 100 Watershed Land Ccwer Maps Figure 63. Rock River Watershed 103 Figure 64. Fox and Des Plaines Rivers Watershed 104 Figure 65. Kankakee, Vermilion and Mackinaw Rivers Watershed 105 Figure 66. Spoon River Watershed 106 Figure 67. Sangamon River Watershed 10^ Figure 68. LaMoine River Watershed 108 Figure 69. Kaskaskia River Watershed 109 Figure 70. Embarras and Vermilion Rivers Watershed 110 Figure 7 1 . Little Wabash River Watershed Ill Figure 72. Big Muddy, Saline and Cache Rivers Watershed 112 UST OF TABLES Chapter 3- Ecosystem Monitoring Results Table 1 . Forest Types Monitored by ForestWatch 12 Table 2. Species with the Highest Importance Values, ForestWatch 15 Table 3- Dominant Plant Species in a Recently Disturbed Forest Compared to a Relatively Undisturbed Forest 16 Table 4. Detection of ForestWatch Indicator Groundcover Plant Species 16 Table 5. Introduced Species in CTAP Forest Sites, by Region 17 Table 6. Detection Rates of Area-Sensitive Bird Species, CTAP Forest Sites 18 Table 7. CTAP Grassland Sites 21 Table 8. Introduced Species in CTAP Grassland Sites, by Region 21 Table 9. Detection Rates for Grassland Birds 22 Table 10. Introduced Species in CTAP Wetland Sites, by Region 24 Table 1 1. Detection Rates for Wetland Birds 25 Table 12. Number of Streams and Sites Monitored by RiverWatch 26 Table 13. MBl: Mean, Standard Deviation, and Range 33 Table 14. Basins with Notably Better or Worse Indicator Vilues Relative to the Average .... 36 Chapter 4. Rock Rfver Watershed Table 15. Watershed Land Cover 38 Table 16. Watershed Indicator Scorecard 39 Table 17. MBI Values 39 CHAin"ER 5. Fox and Des Plaines Rivers Watershed Table 18. Watershed Land Cover 51 Table 19. Watershed Indicator Scorecard 52 Table 20. MBI Values 53 Table 21. Tree Species with the Highest Importance Values 53 Table Of Contents VII Chapter 6. Kankakee, Vermiuon and Mackinaw Ra^rs Watershed Table 22. Watershed Land Cover 60 Table 23. Watershed Indicator Scorecard 60 Table 24. MBI Values 61 Table 25. Tree Species with the Highest Importance Values 61 Chapter 7. Spoon Rtver Watershed Table 26. Watershed Land Cover 67 Table 27. Watershed Indicator Scorecard 68 Table 28. MBI Values 68 Chapter 8. Sangamon River Watershed Table 29. Watershed Land Cover 73 Table 30. Watershed Indicator Scorecard 74 Table 31. MBI Values 74 Table 32. Tree Species with the Highest Importance Values 75 Chapter 9. LaMoine River Watershed Table 33Watershed Land Cover 76 Table 34. Watershed Indicator Scorecard 77 Table 35. MBI Values 77 Table 36. Tree Species with the Highest Importance Values 78 Chapter 10. Kaskaskia Rtver Watershed Table 37. Watershed Land Cover 81 Table 38. Watershed Indicator Scorecard 82 Table 39. MBI Values 82 Table 40. Tree Species with the Highest Importance Values 83 Chapter 1 1 . Embarras and Vermilion Rivers Watershed Table 41. Watershed Land Cover 87 Table 42. Watershed Indicator Scorecard 88 Table 43. MBI Values 88 Table 44. Tree Species with the Highest Importance Values 89 Chapter 12. Little Wabash Rjver Watershed Table 45. Watershed Land Cover 95 Table 46. Watershed Indicator Scorecard 96 Table 47. MBI Values 96 CiLVPTER 13. Bic, Muddy, Saune and Cache Rfvers Watershed Table 48. Watershed Land Cover 97 Table 49. Watershed Indicator Scorecard 98 Table 50. MBI Values 99 Table 51. Tree Species with the Highest Importance Values 99 PHOTO CREDITS Photos by Michael Jeffords except for: p. 2, 16, 101 - EcoWatch p. 18-JackShouba p. 33 - Brian Creutzburg p. 43, 47, 49, 76, 79, 81 , 83, 85 - Joel Dexter p. 52, 58, 67, 70, 92 - James P. Rowen p. 69 - courtesy of the Illinois State Museum p. 74, 89 - Matt Buffington p. 95 - Maggie Friedenbach Summar)' CHAPTER ONE Summary Ecosystems in Illinois are deteriorating, their natural functions disrupted b\' fragmentation and stress. So concluded The Changing Illinois Environment: Critical Trends, a state-of-the-envi- ronment report published in 1994 by the Illinois Department of Energy and Natural Resources (now the Department of Natural Resources). This first "Critical Trends" report recommended that the state begin collecting statewide data on both the extent and condition of its ecosystems in order to deter- mine the most effective and economical natural resources policy. The report quoted Abraham Lincoln: "If we could first know where we are and whither we are tending, we could better judge what we do and how to do it..." To learn "where we are and whither we are tending," the Critical Trends Assessment Program (CTAP) at the Illinois Department of Natural Resources has developed the data collection tools and programs needed to monitor trends in Illinois ecos\stems. ()\er the past several \ears, the (TAP team has completed an atlas of Illinois land cover, an inventor)' of resource rich areas, 16 regional assessments, and several years of ecosystem moni- toring. The team consists of staff from IDNR's Office of Realty and Environmental Planning and Office of Research and Scientific Analysis: the Illinois Slate Museum, Illinois Waste .Management and Research Center, and the Illinois Natural llistor)', State (ieological and Stale Water Surveys. This report provides an overview of each of the CTAP projects. Chapter 1 summarizes the find- ings of each program. Chapter 2 describes the land cover of the state, and Chapter 3 provides initial statewide ecosystem monitoring results. (Chapters 4 through 1 3 are reports on each of the ten Illinois watersheds as defined by the Illinois Streams Information System (ISIS). They provide informa- tion on land cover and resource rich areas and, if available, ecosystem monitoring results and sum- maries of regional assessments. The Department of Natural Resources enlisted dozens of its scientists and researchers, hundreds of volunteers, and numerous data sources and analytical tools to produce the information summarized in this report. This information is vital to protecting, preserving and enhancing Illinois ecosystems. LAND COVER MAPPING Using satellite imagery (shot between 1991-1995) and .spatial databases, CTAP delineated the extent of Illinois ecosystems and published Illinois Land Cover: An Atlas in 1996. The resulting statewide land cover database, also available on compact disk, reveals natural features and artificial structures at a level of detail appropriate for regional analyses. It will be updated periodically to detect changes in the extent of the state's ecosystems. In general, agricultural land dominates the Illinois landscape, covering more than three-fourths — 77.5% — of the state. Specifically: • row crops constitute the single largest land co\er in Illinois with approximately 19.6 million acres, 54.3"' deciduous woods, comprises nearh' i.l million acres or 1 1 .3''" of Illinois' surface, • wetland covers approximately 1.2 million acres or 3-2% of Illinois, TIjis information is vital to protecting, preserving and enhancing Illinois ecosystems. Critical Trends in Illinois Ecosystems If degradation is severe, restoration to pre-disturbance condition will likly require intensive vegetation management • bottomland forest, spread over 809,000 acres (2.2% of the state's land area), is the most prevalent type of wetland, • urban and built up land comprises 4.0% of the state, 5.8% when urban grassland is included, • the remaining 2.1% of the state is open water — lakes, rivers and streams that cover more than 770,000 acres — or barren/exposed land that covers approximately 16,200 acres. RESOURCE RICH AREAS CTAP used land cover data and geo-referenced bio- logical data — quantity of forests, wetlands, Illinois Natural Areas Inventory sites, and Biologically Significant Streams — to determine where the most - ■ .,- ■ ' r ^■■.-'»r''*'-~^-i-^:-"— JBiS ' ■» biologically rich areas of the state are located. The 816 Illinois Environmental Protection Agency watersheds were used as the geographic unit for evaluation. Thirty such areas (Tig. 1) were identified and higlilighted in an Inventory of Resource Rich Areas In Illinois. The Resource Rich Areas: • cover almost one-fifth of the state, encompass- ing seven million acres, • include 45% of the bottomland forest, 34% of the upland forest, and 43% of the nonforested wetland, • range in size from 15,144 to 626,795 acres, • arc distributed throughout the state and gener- ally occur along stream corridors. The largest Resource Rich Areas are Big Rivers, the Southern Till Plain and the Middle Illinois River. The smallest ones arc Sugar River, Thorn C.reek, Des Plaincs River, Illinois Beach and the DuPage River, all in the northern part of the state. The inventory of resource rich areas helped to establish priorities for the state's C^onservation 2000 Ecosystems Program — most of the |-)rogram's Ecosystem Partnerships have at their core a resource-rich area. Ecosystem Partnerships are made up of individuals and interest groups that work together to maintain and enhance ecological and economic conditions within a defined boundary. REGIONAL ASSESSMENTS As Ecosystem Partnerships were formed. CTAP pre- pared regional "Critical Trends'" reports for their areas. Usually based on watershed boundaries, the reports describe an areas geology, water resources, living resources, socio-economics. environmental quality, and archaeological resources. They are designed to provide the baseline information the partnerships need to set priorities and develop management plans. Sixteen of the assessments (Pig. 2) are summarized in chapters 4-13; regional assess- ments for the rest of the state should be completed over the next few years. Some general findings that can be applied statewide include: • habitat fragmentation is a w idespread problem that, in the long term, could limit attempts to maintain and enhance biodiversity. • habitat degradation is a widespread problem that could be slowed or minimized by simply removing the degradation factors, such as grazing, • if degradation is severe, restoration to pre- disturbance condition will likely require intensive vegetation management. • restoring native vegetation along streams would shade the streams, stabilize banks, and filter sediment and chemicals from runoff before they reached the streams, resulting in less siltation and desiccation and lower water temperatures, and • setting prescribed fires in terrestrial ecosys- tems, such as prairies, that need regular burning would m:iintain their characteristics and diversir\'. Many of the regions are unique. For example, the C'achc River basin contains such exceptionally diverse floni and fauna that two o( its wetlands are included in the United Nations list of 15 "Wetlands of International Importance." Tlie Fox River basin is one of the most urban \\alcrshcds in the state, yet it has a rich llora including 102 plant species listed Summar)' Figure 1. Resource Rich Areas DBS PLAINTS RIVER p-HORN CREEK '1'rairiepIrklands VERMILION RIVER lUVER 'UPPER WABASH DRIVER LOWER WABASH RIVER SHAWNia; 1111.1 -S \\("RETACEOUS llll.l-S Critical Trends in Illinois Ecosystems Figure 2. Assessment Areas Summarized in This Report ^H Cache River Basin I I iliinois Headwaters IEmbarras River Basin Sinl(hole Piain Big Rivers Illinois River BluHs ! Spoon River Basin Mackinaw River Basin Kankakee River Valley Upper Des Piaines River Basin Fox River Basin Driltless Area Sugar-Pecatonica Rivers Basin Kishwaukee River Basin H Lower Rock River Basin Upper Rock River Basin County Boundaries I I Illinois Summary as state endangered or threatened and two listed as federally threatened. Because of glacial topography, the Headwaters area gives rise to six major streams that together drain nearly one-third of Illinois. In southwestern Illinois, the Sinkhole Plain is an area of karst topogniphy characterized by sinkholes and caves and is also one of the fastest growing regions of Illinois. ECOSYSTEM MONITORING Wliile these assessments are necessarily based on existing, fragmented data, the Critical Trends program has developed a long-term monitoring network that will provide current information on the condition of the major natural ecosystems. This information will support efforts to preserve, restore, and manage ecosystems across the state. Under the CTAP monitoring plan, C^TAP scientists from the Natural History Survey conduct detailed biological inventories of 150 randomly selected sites (30 per jear rotating on a five-year cycle) for each of four habitat types — forests, streams, wet- lands and grasslands. Trained volunteers in the EcoWatch network carry out less detailed biologi- cal surveys at several hundred sites (currently only at forest (ForestWatch) and stream (RiverWatch) sites, but soon at prairie and wetland sites as well). Together the two groups collect a representative set of biological indicators that measure environ- mental qualit)-. The indicators include information on plants, birds, fishes and aquatic insects that wUl track changes in the four ecosystems. As data accumulates over the years, regional and statewide trends will become apparent. Even with only five years of data certain patterns are clear >- Streams in Illinois have experienced drastic modification over the past 150 years. Most streams that drain prairie landforms have been straightened, their canopies removed, and the watersheds tiled to drain fields more quickly. The data collected by (HAP scientists and RiverWatch volunteers point out some com- mon problems. • Illinois .streams average onl\ 88.6 out of a possible 180 points on a habitat quality index, indicating fair or poor habitat quality along most Illinois streams. Most streams lack natural habitat features such as wooded riparian corridors, winding stream channels, and stable in-stream habitat such as coarse rocks and wood debris. • Most sites across Illinois are so degraded from a century of abuse that relatively few sensitive aquatic insects (EPT taxa) remain in the northern 75% of the state. Overall, the average site contains only 7.1 EPT taxa and 8.9 RiverWatch indicator taxa. Three out of five stream samples are dominated by three or fewer macroinvertebrate taxa, further indicating a lack of diversity. • Indices of organic pollution — the Hilsenhoff Biotic Index (HBI) and the Macroinvertebrate Biotic Index (MBI) — indicate that most streams are at least mod- erately impaired and characterized by organisms that are moderately tolerant of organic pollution and overall stream di.sturbance. • Wliile Illinois streams contain a diversity of fishes — 188 native species — they are often dominated by just two to three fish species, sometimes by one or more of the 15 introduced species found in the state. CTAP and RiverWatch data clearly suggest that some watersheds are better off than others, but none of the 10 ISIS watersheds ranked high on all stream quality indicators. • The Spoon River watershed scored high in all measures of macroinvertebrate diversity and pollution intolerance, but showed below average habitat and fish diversity. • The EmbarrasA'ermilion S. watershed has both diverse macroinvertebrate and fish communities, but the HBI and MBI indicate the organisms are generally pollution tolerant. • The Fox/Des Plaines, Rock, and LaMoine watersheds generally scored below average or average on most indicators. • The lower part of the Big Muddy/ Saline/Cache watershed (streams in the (facile Basin or Shawnee Forest) is relatively pristine according to most stream quality indicators, but the upper part (Big MudiK and Saline basins) where farming is the iloniinant land use has lower stream quality. The Spoon Rit'er watershed scored high in all niec/sures of inacroinrerlebnile diversity and pollu- tion intolerance, but showed heloiv at'erage habitat and fish dii vrsity. Critical Trends in Illinois Ecosystems Forest monitoring data show evidence of disturbance in Illinois forests and ivoodlands. • The Kaskaskia watershed scored low on virtually every biological indicator. >» Two hundred years ago, 38% of Illinois was forested. Today, 14% of the state's land area remains in forest. Forest cover is now slowly increasing, but the plant species composition of our oak and hickory dominated forests is changing due to fire suppression, habitat frag- mentation, and the introduction of non-native species. Forest monitoring data show evidence of disturbance in Illinois forests and wood- lands. • The average CTAP monitoring site con- tains 58 native plant species and only three introduced species, but where they are found non-natives tend to crowd out native species. • The most important species in the ground cover layer include Virginia creeper, red maple, sugar maple, grass-leaved sedge, wild geranium, wood nettle, clearweed, mayapple, black snakeroot, and poison ivy. In the shrub layer they include spicebush, Missouri gooseberry, black raspberry, bristly greenbriar, and poison ivy as well as saplings of sugar maple, paw paw, bitternut hickory, rough-leaved dogwood, white ash, green ash, hop hornbeam, black cherry, and American elm. • The shrub layer is the layer most dominat- ed by introduced plants. More than 70% of shrub stems counted at ForestWatch sites are in\'asive, generall)' introduced species. The most dominant are buckthorn and shrub honeysuckle in the north, Japanese honeysuckle in southern and central Illinois, and multi-noni rose throughout the state. • Invasive ground cover plants, such as garlic mustard and ground ivy. cover more than two and one-half times the area of distur- bance-sensitive indicator species such as Dutchman's breeches and white trillium. • Except for buckthorn and white mulberry, introduced trees are not a problem in the interior of most Illinois forests. • Northern Illinois forests are the most degraded by invasive plants, while south- ern Illinois forests are the least affected by introduced species. • A little over one-third of the oak-hickory forest sites monitored by ForestWatch show evidence of "maple takeover' (because fire has been suppressed, young sugar maples are the dominant saplings instead of oaks and hickories). • Nearly one out of three sites with flower- ing dogwoods show signs of anthracnose. a fungal disease that threatens to wipe out flowering dogwoods, much as chestnut blight and Dutch elm disease decimated chestnut and American elm populations in the past. >* CTAP bird censusing clearly shows the importance of continuous forest habitat. • An average of 6.4 bird species considered moderately to higlily sensitive to habitat fragmentation were detected at forest sampling sites. • At isolated sites where there was little additional forest habitat within one kilo- meter, no area-sensiti\e birds were found. • At sites with a high percentage of forest in the surrounding landscape, as many as 15 sensitive species were detected. ^ About 61% of the pre-European settlement landscape of Illinois \\as prairie. Nearly 20'\i of the state is still characterized as grassland, although only 0.01% of the original prairie per- sists in a high-quality condition. Today s typical grassland is much less diverse than yesterday "s prairie. • (TAP plots contain an average of 20 plant species. ~.S of ihcm introduced, while a high quality pr.iirie contains as many as IOO-l-»0 different plant species. Summarv • The most common native species in Illinois grasslands include red top grass, big bluestem, trumpet creeper, switch grass, beadgrass, and common goldenrod. • Of the terrestrial habitats, grasslands are the most heavily dominated by introduced species with 6() of 71 monitoring sites dominated by them. • Meadow fescue and Kentucky and Canadian blue grasses are the most domi- nant introduced species. • An average of fewer than two grassland- dependent bird species nest at the sites (a high quality prairie would contain 6-12). • Except for the eastern meadowlark, brown-headed cowbtrds (nest parasites) were detected more often than any grass- land-dependent bird species. *- Wetlands in Illinois have declined from pre-set- tlement estimates of 23% of the state to only 3.2%. Of the remaining wetlands, few remain in a high-quality condition, and man)' are severely degraded due to non-native species invasion, sil- tation, changes in hydrology, runoff of roadway de-icing salts, drainage activities, and grazing. PLAN IT EARTH • CTAP wetland sites contain an average of 1 S plant species, with two of them intro- duced. Sites containing introduced species have considerably lower biodiversity. • Reed canary grass, the most commonly encountered introduced species, often completely dominates a site, replacing most native species and almost forming a monoculture. It was the dominant species at 22 of 78 monitoring sites. • Some monitoring sites were diverse and still contain a high proportion of native species. Southern Illinois wetlands, in particular, seem to be the least affected b) introduced species. • The most common native species include Joe Pye weed, rice-cut grass, tall reed grass, river bulrush, water smartweed, and broad- leaved cattail. • The number of wetland-dependent bird species found at the typical site is low, 1.3 species on average. A healthy wetland should host 6-10 wetland dependent species. CI A I' wetland sites contain an average of 15 plant species. After The Changing Illinois Environment: Critical Trends was published, the Illinois State Board of Education and Illinois Board of Higlier Education asked CTAP staff to help develop a high school science curriculum ba.sed on the report. The resulting FIAN-IT EARITI curriculum (Pairing Learners And Nature with Innovative Technology' for the Environmental Asses.sment of Resources Trends and Habitats) integrates state education goals with CTAP findings and data, as well as EcoWatch monitoring procedures. A PLAN-IT partner. Dr. Marylin Lisowski of Eastern Illinois University, received a National Science l-oundation grant to train science teachers on using the curriculum and the monitoring proce- dures. As of 1999, more than three hundred Illinois teachers had been trained. Hie curriculum focuses on Illinois ecology and is directed to high .school teachers who wish to incorporate environmental science and field work into their classes. Many teachers take their students to a local forest or stream, etc., where the students use EcoWatch procedures to collect data and submit it to IDNR, where it is used for CTAP eco.system trends analysis. The curriculum is divided into six ecosys- tems: rivers and streams, forests, wetlands, prairies, agnxsystems and urban. Activities in the curriculum module either provide background information on the biodiversity of Illinois' ecosystems or outline the EcoWatch monitoring procedures for the ecosystem being studied. Each activit)- was tested in high .school scieiice cla.ssrooms and re-written as needed. The curricukmi design team included high school science teachers, university' education professors, scholastic a.ssessment specialists, Illinois Natural Histor)' Survey scientists and IDNR stall. Critical Trends in Illinois Ecosystems CHAPTER TWO State^vide Land Cover 1=* ■ Illinois' grassland is primarily rural and is concentrated in the northivestern and southwestern areas of the state. Illinois counties range in size from 1 10,190 acres in Putnam County to 759,040 in McLean County; the median is 329,377 acres. The typical Illinois county has nearly 190,000 acres of cropland, more than 56,000 acres of rural grassland, approximately 42,000 acres of forested and wooded land, less than 9,000 acres of wetland and approximately 11,000 acres of open water. It also has about 8,000 acres of urban or other built-up land and roughly 50 acres of barren land. The following provides statewide information on seven land cover categories: cropland, grass- land, forest/woodland, wetland, urban/built-up land, open water, and barren/exposed land. Figure 4 illustrates the land cover of the state as a whole. CROPLAND >■ All 102 Illinois counties have cropland; the con- centration ranges from 4.0% in Cook County to 85.2% in Piatt County. • Eight counties have more than 80% of their acreage in crops. • Twent)'-two counties have 70-79% of their acreage in crops. • Twenty-eight counties are 60-69% crop covered. >■ On average, Illinois counties plant 62.6% of their acreage in crops. >- Nearly 91% or 19.6 million acres of the state's cropland is in row crops, primarily corn and soybeans. • Small grains account for most of the remaining 9% of cropland. • Orchards cover only about 16,000 acres. GRASSLAND *- Illinois' gi-assland is primarily rural. • About 91% of the state's grasses are rural incluiling pastures, rural roadsides, hay/ alfalfa, etc. Only 9% of the grassland is located in urban areas, primarih' residential areas, air- ports, golf courses and other open spaces. E FG ■ A Cropland (60%) ■ B Grassland (19.2%) n C Upland forest (11.3%) n D Urban/built-up (4.0%) ■ E Bottomland forest (2.2%) D F Water (2.1%) ■ G Non-forested wetlands (1 .0%) Figure 3- Statewide land cover percentages 2^ Urban grassland is concentrated in or near the Chicago metropolitan area. • Sixty percent of the state's urban grassland, or about 240,900 acres, is located in Cook, Lake, DuPage. Will and K:uie counties. • Cook County- alone has more than ~5,(XX) acres of urban grassland. >■ Rural grassland is concentrated in the nonh- western and southwestern areas of the state. • Fifteen counties have more than 25'>b of their total acreage in rural grasses. FORESTA^OODLAND >^ Illinois has more than 4 million acres of forest and ^^'oodland. >- All Illinois counties have forest or woodland; the predominiuit tApe is deciduous woods (87.9%, about 3 (i million acres). • Open canopy woods — sparsely wooded land in both rural and urban areas — co\ er more than tOO,000 acres. • C~,oniferous woodland is found on only 72,000 acres. Statewide Land Cover Figure 4. Statewide land cover Forest- Deciduous.closed canopy Forest- Deciduous.open canopy Forest- Coniferous Wetland- Shallow m;irsh Wetland- Deep marsh Wethind- Swamp Wetland- Forested Wetland- Shallow open water I Open water deeper than Zm I Urban- High density I Urban- Medium high density 1 Urban- Medium density I Urban- Low density I Urban- Grassland I Ag- Row crops I Ag- Small grains I Ag- Rural grassland I Ag- f)rch;irds and nurseries I Barren and e\|'K)scd land 10 Critical Trends in Illinois Ecosystems Four Illinois counties have more than 10% of their area covered by wetland. • Forested or wooded areas cover an average of 10.8% of each county. f^ The concentration of forested and wooded land ranges from 0.4% of Ford County to 58.4% of Pope County. • Two counties, Pope and Hardin, are more than 50% forested or wooded. • An additional nine counties are 25 to 49% forested or wooded. WETLAND >■ Illinois has nearly 1.2 million acres or 32% of its surface in wetland. • The majority of wetland, 69%, is bottom- land forest — approximately 809,000 acres situated along the state's rivers. • Shallow water wetland comprises 14.9% and shallow marsh/wet meadow comprises 12.0% of all wetland. • Deep marsh and swamp combined are only 4.0% of the total wetland. >- All counties have some bottomland forest, shallow and deep marsh, wet meadow, and shallow water wetland. • Four Illinois counties have more than 1 0% of their area covered by wetland (Alexander, Calhoun, Clinton, and Lake); 24 counties have 5 to 10% of their area in wetland. • Twenty-seven counties have swamp, comprising a total of 1 1 .726 acres, mostly situated near the southern tip of the state. URBAN/BUILT-UP LAND >- Illinois has 10 metropolitan areas. • The largest, Chicago, encompasses nine counties. • The second ranked metropolitan area. East St. Louis, covers five counties. • The Peoria and Rockford metropolitan areas take in three counties each. • Springfield and Rock Island extend over two counties each. • There are four single-count)' metropolitan areas: Bloomington, Champaign. Kankakee and Decatur >- Urban and built-up land constitutes 4.0% of Illinois' surface. • Low density and medium densit%- land uses, primarily residential, account for 57.5% of urban and built-up land. • High densit)' development, mosth urban centers, accounts for another 20.9%- • Transportation, including major roadways and rails, comprises 21.6% of all urban and built-up land. OPEN WATER >- Roughly two-thirds of Illinois' boundary is defined by rivers. • The Mississippi. Ohio and Wabash rivers border the state. >- Lakes, rivers and perennial streams cover 2.1% of Illinois' surface. • The Illinois River bisects the state from St. Louis to Chicago. • Other major rivers include the Rock River in the north, the Kaskaskia in the south and the Mackinaw and Sangamon rivers in the center of the state. 5* Twenty-four counties contain more than 10,000 acres of lakes, rivers and streams. • These counties are concentrated along the Mississippi and Illinois ri\ers. BARREN/EXPOSED LAND >" Twent)'-five Illinois counties contain barren or exposed land, mostly quarries. • Acreage of barren/exposed land is small, ranging from one acre in Macon and "Williamson counties to 1.823 in LaSalle County. >* Onh' four counties (Cook, LaS;illc. McHenr> and Will) contain more than 1.000 acres of barren/exposed land. Ecosystem Monitoring Results 11 CHAPTER THREE Ecosystem Monitoring Results Are environmental conditions in the state getting better or worse? To answer this question, the Critical Trends Assessment Program has begun implementing its monitoring plan to track statewide trends in forest, wetland, grassland, and stream habitats. CTAP scientists conduct detailed biological inventories of 1 50 randomly selected sites (30 per year, rotating on a five-year cycle) for each of the four habitat types, while EcoWatch volunteers carry out less detailed biological surveys at several hundred sites each year (currently only at forest and stream sites). CTAP staff use the statewide GIS land cover database to select potential sampling sites and estab- lished criteria to ensure that a site is representative of the intended habitat type. CTAP sites are selected from random!)- selected Public Land Survey Townships, while EcoWatch sites are selected from Public Land Survey Sections. In each township or section only one site is sampled. In addition, EcoWatch volunteers may select their own sites (consistent with minimum site criteria). Since it is not feasible to measure all compo- nents of the environment, the monitoring program focases on a set of representative indicators — data on plants, birds, aquatic insects, and fish — to mea- sure environmental change. Data will be available on terrestrial insects within the next few years. • Vascular plants are being monitored in forest, wetland, and grassland habitats to detect problems of biotic integrity. Encroachment by invasive and/or exotic species, di.sea.se, or altered fire regimes can lead to changes in com- munity structure, the lo.ss of sensitive native plant species, and the homogeni/ation of historically diverse plant communities. C7TAP indicators for plant communities include the diversity of native plant species and the percent cover of exotic versus native plants. Other indicators are also being investigated. Long-term monitoring of these indicators will reveal spatial as well as temporal patterns of change within these plant communities. Bird populations are being monitored in forests, wetlands, and grasslands. Indicators include, but are not limited to, the abundance and diversity of habitat specialists (species that can only live in wetlands, for example), threatened and endangered species, area-sensitive species (i.e., sensitive to habitat fragmentation), and the ratio of cowbirds (brood parasites) to host species. Because birds are highly mobile, these indicators can reflect landscape conditions that extend beyond the boundaries of the habitat patches being investigated. Aquatic insects are used b\' (HAP scientists to determine the EVY index — the number of species of Ephemeroptera (mayflies), Plecoplera (stoneflies), and Trichoptera (cad- disdies) in a sample. EIT species are relatively intolerant of pollution, and the EPT index is one of the most efficient indices of stream health. Because sensitive aquatic insects are less mobile than fish and potential!) respond more C|uickl)' to clianges in stream healtli. they reflect site-specific imjiacls heller tlian fish. EFF species are abundant in nioM Mreams, wliile the numbers of fish in the smallest streams ma) be meager Ix'oWaich volunteers collect both ac|ualic insects and other benthic macroinvertebraies (creatures without a The monitoring pro^irant focuses on a set of repivsentatii'e indicators — data on plants, hints, aquatic insects, and fish — to measure environmental chanf^e. 12 Critical Trends in Illinois Ecosystems CTAP moniturs the biocUversity of forest communities, including changes in the species composition of the plant and bird populations, as well as the status of invasive species. backbone that live on stream bottoms) that are relatively easy to identify and represent a wide range of tolerance to organic pollution. As indicators of stream health they help measure biodiversity (taxa richness and taxa dominance) as well as pollution tolerance (macroinverte- brate biotic index (MBO and EPT taxa richness). • Fish communities are good indicators of long-term impacts that occur over a broad range of scales — they feed at a range of trophic levels (other fish, insects, plants, etc.), and are consumed by humans for food. Also, they are relatively easy to collect, are directly related to water quaUty standards used by many government agencies, and account for nearly half of the endangered vertebrate species and subspecies in the U.S. The environ- mental tolerance, life histories, and geographic distributions are better known for fishes than for any other group of freshwater organisms. Indicators generated from data on fishes include species richness, relative abundance, community structure (ratios of the different types of fishes in the samples), and the diversity and abundance of hybrids and exotic species. FORESTS During the first half of the 19th century forests cov- ered roughly 38% (13.8 million acres) of Illinois. Currently only about 14% (4.9 million acres) of the state remains in forest. Most of the present-day forests have been fragmented into very small parcels of land, and the abundance of species that require large forested tracts to survive, such as the pileated woodpecker and wood thrush, have declined. Small fragmented parcels are also more susceptible to intrusion by invasive species of plants and animals. (HAP monitors the biodiversity of forest communities, including changes in the species composition of the plant and bird popula- tions, as well as the status of invasive species. Forest Plants Between 1997 and 1999 CTAP botanists monitored 73 randomly selected forest sites throughout the state (Fig. 5). In addition, EcoWatch volunteers monitored 120 sites in the spring and fall of 1998 and 1999 (Fig. 6). Data on vascular plants were collected from the ground, shrub, and tree lasers in the interior of forest patches. The preliminary analysis provides a characterization of the t>'pes of forests found in Illinois and some of the threats that they face. Of the 52 sites monitored by ForestWatch in the fall of 1998,40 were upland forests and 12 were bot- tomland forests. Tliirty-(5ne of the uphmd forests were oak-liickory, the most common (about one- half) type of forest in lUinois.The bottomland forests were predominantly ash-elm-maple (Table 1). Table 1. Forest lypes Monitored by FoivstMatch Upland forests: # of sites: Oak-hickory 31 Maple-ash-basswood 4 Bur oak 2 Ttilip tree 2 Beech-maple 1 Bottomland forests: Ash-elm-mapic 10 Ash-cottonwood 1 Scrub 1 Ecosystem Monitoring Results 13 Figure 5. CTAP Forest Monitoring Sites, 1997-1999 14 Critical Trends in Illinois Ecosystems Figure 6. ForestWatch Monitoring Sites, 1998-1999 Ecos>'stem Monitoring Results 15 Sugar Maple Buckthorn 5% Hawthorn Black Cherry Other (65 species) 37% Table 2. Species with the Highest Importance Values, ForestWatch Figure 7. Most abundant species, ForestWatch The most abundant taxa were hickon' and ash, followed b)' the individual species slipper)' elm, white oak, sugar maple, and buckthorn (Figure J). Tlie species with the greatest basal area, which takes into account the size of trees, were white oak followed by hickor)', ash, northern red oak, sugar maple and slipper)' elm (Figure 8). (Note: hickor)' and ash have higher ranks because they include several species within each genus, while most other taxa listed arc individual species.) It is useful to look at abundance and basal area separately, since some species are numerically dominant (i.e. slip- per)' elm) while others are dominant ill terms of their size (i.e., white oak). These two measures are used to calculate the importance value of a tree species: the more dominant the species, the greater the importance value. The species with the highest importance value was white oak followed by hickor)' and ash (Table 2). Ash Kidrory 10% IJ N Red Oak e% ^^^ Sugar Mapio White Oak 20% 1 ^ Si Oinof (6S ipcoM) 32X ^^^K Skivery Elm ^^^^H Bur Oak ^^^^^^H Basswood ^ ^\^^ ^7 Swamp Whito Onk ^^^/ Pin Oak W " species Importance value White oak Hickor)'* Ash* Slippery elm Red t)ak Sugar maple Basswood Hawthorn Bur oak Hackberry 13.7 11.7 8.9 7.5 6.0 5.3 3.3 2.9 2.8 2.8 Figure 8. Species with the givatest basal area, ForestWatch * Represents more than one species of hickory and ash trees. The total number of vascular j'jlant species detected on the CTAP forest plots (including all trees, shrubs, and ground cover) ranged from 19 to 108 species, with an average of 61 species per site. However unlike in grasslands and wetlands, the number of species is not necessaril)' an indication of the quality of the habitat. In general, upland sites tended to be more diverse than bottomlands. The most important native species in the groimd cover layer include Virginia creeper (which has the highest importance value at 20 sites), red maple, sugar maple, grass-leaved sedge, wild geranium, wood nettle, clearweed, mayapple, black snakeroot, and poison ivy. In the shrub kner the)' included spicebush, Missouri gooseberr)', black raspberr), bristly greenbriar, and poi.son ivy as well as saplings of sugar maple, paw paw, bitternut hickory, rough-leaved dogwood, white ash, green ash, hop hornbeam, black cherry, and ^Vmerican elm. Based on information received from land- owners and preliminary analyses of species composition, many forest sites are in the early to intermediate stages of forest succession. That is, they are relalivel) )()ung forests — often small woodlots — showing evidence of past or present grazing or logging, or the land wa.s farmed at some point tluring its historx. Table }< com|')ares a t) pical disturbed site ilominated in each stratification layer by sim-loving plains, and an older forest dominated by shade-loving species indicative of the later forest successional .stages. (HAP scientists rarely 16 Critical Trends in Illinois Ecosystems Table 3- Dominant Plant Species* in a Recently Disturbed Forest Compared to a Relatively Undisturbed Forest Disturbance- sensitive species were found (It only one-third of ForestWatch sites Forest with recent disturbance Forest relatively free of disturbance Herbaceous ground layer Multiflord rose + White avens Clearweed UndersUiry shrubs and saplings Multiflora Rose + Amur honeysuckle + Wild black cherry Canopy trees Honeylocust Hackberry Wild black cherry Herbaceous ground layer Canada wood nettle Wild ginger Common black snakeroot Understory shrubs and saplings Paw paw Ohio buckeye Spicebush Canopy trees Basswood White ash Hackberry * Based on importance values (TV). [V for ground layer was calculated by adding the relative frequency and percent cover for each species, FVfor understory was calculated by adding the relative free/uency and density for each species. IV for canopy was calculated by adding the relative frequency and basal area for each species. + Non-native species encountered older growth forests that were rela- tively free from disturbance for many decades. Because of the relatively disturbed nature of most Illinois forests, three common problems exist; 1) they have lost valuable disturbance-sensitive plants, 2) they are being dominated by introduced or invasive species, and 3) because fire has been sup- pressed, they are being taken over by maple trees. Some native species are very sensitive to dis- turbances, causing them to be easil)' extirpated. Such species were found at only one-third of ForestWatch sites (Table 4); their loss provides an opening for weedy, disturbance-tolcnmt species. While forest sites throughout Illinois generally have a low percentage of introduced plant species compared to wetlands and grasslands — on average only three of the 61 species are introduced — most forests contain some. Even though relativeh' few introduced species may be detected at a site, their dominance, in terms of relative cover or density-, may be disproportionally high and they may totall)' dominate the understor>' of the forest. Table 4. Detection of ForestWatch Indicator Groundcover Plant Species Disturbance-Sensitive Species Detection Groundcover (% of sites) (m-/ha) Blue cohosh 7% -.01 White trilliuni (all species) 7% 0.49 Dolls eyes 6% 2.75 Large-flowered bellwon 12% 2.50 Bleeding hearts (both species) 19% 26.67 Maidenhair fern 4% 1.52 Virginia spiderwort 15% 0.98 Hepatica (both varieties) 6% 0.25 Common Native Species Virginia bluebells na 0.50 Wild columbine na 0.25 Blue phlox na 13.28 Red trilliuni fia 15.1- Bluc-e\cd Mar>' na 0.-5 Wild geranium na 134.4.3 Swamp buttercup na 18.96 Sensitive fern na 2.29 Non-Native Species Carlic mu.stard h\\ 105.5^ Dames rocket 1% Mone>\vort i% 28.-1 Ciround i\y 22"., 28.86 * na = not available Introduced species were found in S8 of the ^.^ forested sites \isited by CTAP botanists (Tiible S). At the sites monitored by ForestWatch \olunteers. nt)n-nati\c ground cover species were found to cover more than two and one-half times the total area co\ered b\ disturbance-sensitive species. In the shrub layer of the forest, in\asive t;ixa a\eniged 1,210 stems per hectare compared to only 490 for non-invasive shrubs, or more than "'O'^ of all shrub stems counted (Fig. 9). When present, these inva- sive, introduced species constitute a major form of environmental degradation. Ecosystem Monitoring Results 17 Table 5. Introduced Species in CTAP Forest Sites, by Region (number of sites monitored is in parentheses) North (18) Cum R.\i. (35) Soi TH (20) State (73) Species # sites # sites dominant # sites # sites dominant # sites # sites dominant # sites Multiflora rose 9 19 4 6 34 Honeysuckle shrub 6 1 7 14 Japanese hone)'sucklc 4 3 6 1 10 Garlic mustard 5 2 2 7 Buckthorn 4 4 2 6 Non-invaslve vines Japanese honeysuckle Non-invasive shnjbs Cranberry Shmb Honeysuckle Gooseberry Multillora Rose 50 100 150 200 250 300 350 400 450 500 Stems per hectare Figure 9- Number of invasive and non-invasive shrub arui vine stems found at 52 ForestWatch sites (a hectare = 2.471 acres) A few introduced plant species such as garlic mustard, buckthorn, shrub honeysuckle, Japanese honeysuckle, and multiflora rose have become common invasive plants regionally (Fig. 10). Some native species, such as gooseberry, can also be inva- sive. Garlic mustard is a serious problem in the Chicago region, but is not widespread in the south- ern portion of the state. Buckthorn has proliferated in the shrub layer of forests throughout much of northern Illinois, and its aiiimdance in the tret sur\ey further indicates how well-established buck- thorn is becoming in northern forests. Honeysuckle shrubs were conimonl) found in northern and western counties, whereas Japanese honeysuckle was a problem in central and southern counties. Multillora rose was the most frec|iieiul\ encoun- tered introduced species (detected at 3 i sites) and was seen in all regions of the state. Southern Illinois had the fewest sites with dominant introduced species. This could reflect its distance from the ports, horticultural areas, and urban landscapes where introductions usually occur m^ Figure 10. The percentage of non-native plants* at CTAP forest sites, by layer and region * the ground layer is measured by the coivr of the plants, the shrub layer by the number of stems, and the tree layer by the basal area Evidence of potential maple takeover was pre- sent at 1 1 of the 40 ForestWatch upland sites. Maple takeover refers to a tendency of sugar maples to become established and replace formerly dominant tree species when fire is suppressed. Maple takeover often occurs in concert with a decline in oak species and, to a lesser extent, hickories. Tlw Chcinging Illinois liiwininiiicnl: Critical I'lvnds reporteil liiai between I9(i2 anil 1985 maples increased 4 l-tbld while oaks were down 14%. Figure I 1 illustrates a Forest Watch site in Pope (x)uiil\ llial apjiears to be experiencing maple takeover. Multiflora rose was the most frequently encountered introduced species and was seen in all regions of the state. 18 Critical Trends in Illinois Ecosystems An average of 6.4 forest-dependent bird species was detected at each CTAP site in 1997-1998. ■Sugar Maple DOak ■HicKory 1 Ji. 5-10 101-20 201-30 30 1-«] 401-50 50 1-60 >60 Tree diameler in centmeters Figure 11. Maple takeover at Fern Trail Forest Finally, ForestWatch volunteers also collected data on the presence of gypsy moth (a pest intro- duced from Europe) egg masses and signs of dogwood anthracnose.When present in large num- bers, gypsy moth caterpillars can defoliate a forest and lead to tree mortality. Currently, they are found primarily in northern Illinois. Anthracnose is a fungal disease introduced from Asia that can deci- mate flowering dogwoods, which occur primarily in the southern half of Illinois. Anthracnose can be compared to chestnut blight and Dutch elm dis- ease, wliich have affected chestnut and elm trees across the eastern United States. No g>'psy moth egg masses were found at any site, but five of 16 sites with flowering dogwood reported evidence of anthracnose. Forest Birds Each species of bird exhibits a different degree of habitat specialization. Some species, such as the introduced European starling, are habitat general- ists, which may partially explain why they have successfully spread throughout the countr)'. Other species are higlily specific in their habitat require- ments, which can include a certain minimimi area of habitat as well as a specific type of habitat. The presence or absence of these specialist species can therefore provide information about the qualitv' of a habitat. The 24 species listed in Table 6 are area- sensitive forest-dependent species; their diversity and abundance can serve as indicators of forest conditions in Illinois. An average of 6.4 forest-dependent bird species was detected at each CTAP site in 199"'- 1998. These species are expected to decline in abimdance as forest habitat is lost or broken into small fragments. Ten of the 24 area-sensitive species are considered Table 6. Detection Rates of Area-Sensitive Bird Species, CTAP Forest Sites Highly area sensitive Pileated woodpecker Ovenbird Louisiana waterthrush Worm-eating warbler (S) American redstart Brown creeper Cerulean warbler Veery Black and white warbler Hooded warbler Nest parasite Brown-headed cowbird Detection Moderately area sensitive Detection (% sites) (% sites) 16% White-breasted nuthatch 82% 16% Tufted titmouse 78% 10% Yellow-billed cuckoo 66% 6% Red-eyed vireo 64% 4% Scarlet tanager 44% 2% Wood thrush 42% 2% Blue-gray gnatcatcher 42% Acadian flycatcher (As) 40% Kentucky warbler (As) 32% \'cllow-thrc)ated \ireo 28% Hair) wot)dpecker 22% Summer tiuiager (As) 18% 84% Northern parula 16% \ellow-throated v\ arbler (As) 6% * Species on the edge of their range or those not adecpiately censused by point counts (e.g. raptors and night birds) are not included (S) = predominantly in southern Illinois (As) = statewide, but /)rcdoniin the plant species in it. CTAP monitoring focuses on the prevalence of introduced species and disturbance- sensitive species. The presence and pervasiveness of these species reflect the ecological condition of the grassland. 16 14 0)12 £10 o •»> o 'I 8 U) c 0) t 6 CO 0) (5 o 4 6 • • Line of best fit 10 20 30 40 50 60 70 80 % of landscape that is forested within 1 km 90 100 Figure 12. The relationship between forest bird diversity and the amount of forest in the surrounding landscape Grassland Plants From 1997 to 1999 CTAP botanists monitored 71 randomly selected grassland sites (Fig. 13). On aver- age, 8.6 randomly selected potential sites were visited before a grassland site was found that met minimum CTAP criteria for sampling. Man)' poten- tial sites were rejected because they were planted in monocultures or were otherwise highly manicured. The high rejection rate means that far less than the 19.2% of the .state's land cover that is classified as grassland habitat is actualh functioning as a natural grassland ecosystem. I'he monitored sites ranged from planted waterways and roadsides with low s|-)ecies diversity to medium-quality prairies with higher diversity (Table 7). Important indicators of habitat conditions within grasslands include vascular plant species richness and the presence of introduced species. Statewide, the plots at these grassland sites contain an average of 20 plant species: lowest diversity sites averaged six species per site and highest diversity sites (prairie remnants) averaged 33 species per site. By comparison, high quality prairies may contain 100-1 tO species in only a few acres. Citnvntiy only about J,.iOO aavs of high cjualit}' prairie remain, which is about 0.0/% (fthe /uvsettlement acreage. 20 Critical Trends in Illinois Ecosystems Figure 13. CTAP Grassland Monitoring Sites, 1997-1999 OEKALa KATC .* . Ecosystem Monitoring Results 21 Important native species in Illinois grasslands include red top grass, big bluestem, trumpet creeper, switch grass, beadgrass, and common goldenrod. Table 7. CTAP Grassland Sites Grassland type % of sites Average # of plant species per site Successional field 33% 24 Mowed pasture 14% 16 Lightly grazed pasture 12% 21 Prairie remnant 12% 33 Riglit-of-way 10% 11 Heavily grazed pasture 7% 15 Utilit>' planted field 7% 9 Within-crop utilit)' strip 5% 6 The grassland sites also averaged seven and one-half non-native species, or 38% of the species detected per site. The number of introduced species was fairly constant across most sites. Of the terrestrial habitats, grasslands were the most heavily dominated by introduced species, with 60 of the 71 sites dominated by them. The grassland layer with the greatest coverage of introduced .species was the ground layer (Fig. 14). Introduced shrubs appear to be encroaching upon the state's grasslands, although no one species is dominant. Introduced trees appeared to be a problem only in central Illinois, probably because white mulberry seeds are scattered by birds and species such as osage orange u.sed to be planted as fencerows. Figure 14. We percentage of non-native plants* at CTAP grasslands sites, by layer and region * the gmiiiul layer is measured by the cuver of the plants, the shrub layer Ir}' the number of stems, and the tree layer by the basal area Meadow fescue and Kentucky and Canadian blue grasses, all common pasture mixes, were the dominant introduced species across the state (Table 8). They are prevalent because most Illinois grasslands are no longer native prairie habitats, but instead have been planted or altered with intro- duced grass mixtures for uses such as pastures and roadsides. Over time, these areas gradually become repopulated with pioneer plant species, with the result that most current grassland habitat contains a mixture of introduced and native plant species. Grassland Birds To assure that sample sites are at least marginally suitable for grassland birds, (TAP ornithologists census birds in grassland patches of at least 10 Table 8. Introduced Species in CTAP Grassland Sites, by Region (number of sites monitored is in paivntheses) Northern (14) Ckntrai. (4 1 ) StxniiuRN (16) Stati:(7I) Species # sites # sites dominant # sites # sites dominant # sites # sites dominant # sites Hungarian brome 9 3 18 5 1 1 28 Meadow fescue 8 1 25 14 10 9 43 Tall fescue 3 3 3 Kentucky bluegrass 6 5 22 6 11 39 Canadian bluegra.ss 5 1 7 4 3 15 Orchard grass 4 1 11 4 4 19 22 Critical Trends in Illinois Ecosystems Historically, tvetlands covered at least 23% of Illinois. The remaining natural wetlands now occupy only 3.2"/n of Illinois. acres. The 12 species listed in Table 9 are highly dependent on grasslands and their presence is an indicator of grassland quality. CTAP detected an average of only 1 .8 of these bird species per site in the 45 grasslands censused in 1997-1998. While some of the 12 species do not occur statewide, and high quality sites in southern Illinois might not be expected to have more than about six species, all 12 could occur in high quality grasslands in northern Illinois. Nonetheless, in comparison to his- torical information, a statewide average of 1.8 species per site is very low. Moreover, the most commonly detected grassland species exhibit only low to moderate sensitivity to grassland frag- mentation (i.e. dickcissel, eastern meadowlark). Brown-headed cowbirds were detected at 62% of the sites. This species occasionally parasitizes grass- land bird nests and their abundance suggests that reproductive success among grassland birds may be low. In other words, conditions may be worse than what might be inferred based only on census data. Table 9. Detection Rates for Grassland Birds draining, filling, clearing, and urban development. The remaining natural wetlands now occupy only 3.2% of Illinois, and habitat loss continues. Bird Species Sensitivity Detection rate (»/o of sites) Northern harrier* High 2.2% Upland sandpiper* High not detected Short-eared owl* High not detected Henslow's sparrow* High 11.1% Savannah sparrow High 2.2% Bobolink High 6.7% Sedge wren Medium 11/1% Grasshopper sparrow Medium 22.2% Eastern meadowlark Medium 68.9% Western meadowlark Medium not detected Dickcissel Low 51.1% Vesper sparrow Low 2.2% (Brown-headed cowbird) (Nest parasite) (62.2%) * state endangered species WETLANDS Historically, wetlands covered at least 23% of Illinois. In the last two hundred years, Illinois has lost approximately 9()"ii of its wetlands as a result of Furthermore, most remaining wetlands are becoming degraded due to fragmentation, siltation. altered hydrological conditions, and the invasion of introduced species. Highly invasive, introduced plant species such as reed canar)- grass, the com- mon reed, and purple loosestrife can dominate disturbed wetlands and exclude native plant species, resulting in a loss of biodiversity. Wetland bird and insect communities are especially sensitive to changes in hydrology, plant species composition, and habitat loss. To assess the biodiversity' of palus- trine emergent wetlands, CTAP scientists monitor changes in species composition, including the prevalence of introduced species and their effects on wetland communities. Wetland Plants In comparison to disturbed wetlands, high quality sites are relatively diverse and free from introduced species. Therefore, species richness and the pres- ence of introduced plant species are indicators of habitat quality. CTAP collected phmt data in 78 randomly selected sites from 1997 to 1999 (Fig. 15). Species information was recorded from the ground cover, shrub layer, and tree la\er (\\hen present). Tlie types of palustrine emergent wetlands moni- tored ranged from marshes with open water to sedge meadows to wet depressions in fallow agriculture fields. Plant diversity within the sample plots averaged 1 S species per site, but ranged from one to 39 species. Tlic most import;mt native species include Joe I*\e weed, rice-cut grass, t;ill reed grass, river bulrush, water smartweed. and broad-lea\ed cattail. The average number oi introduced species jier Ecosystem Monitoring Results 23 Figure 15. CTAP Wetland Monitoring Sites, 1997-1999 ^ -^' UAS^rir 24 Critical Trends in Illinois Ecosystems Table 10. Introduced Species in CLAP Wetland Sites, by Region (number of sites monitored is in parentheses) Northern (22) Central (37) Southern (19) State CS) Species # sites # sites dominant # sites # sites dominant # sites # sites dominant # sites Meadow fescue Narrow-leaved cattail Reed canary grass Barnyard grass Common reed* 1 2 1 13 6 2 1 6 4 20 16 7 1 2 5 5 6 5 2 5 9 38 15 6 ■ species locally native in Illinois, but becoming invasive out of its original range site was two; those of greatest concern were several grasses and the narrow-leaved cattail (Table 10). Northern and central Illinois wetlands were most heavily dominated by reed canary grass and meadow fescue, while southern Illinois wetlands most often contained the common reed — an invasive native species. A higher percentage of introduced species were generally found at lower diversity sites. Where reed canary grass — the most commonly encoun- tered introduced species — was found it had replaced most native species, often nearly forming a monoculture. Reed canary grass was, in fact, the dominant species at 22 of the 78 sites sampled. While most Illinois wetlands have been altered, some monitored sites arc still diverse and contain a high proportion of native species, particularly in Southern Illinois (Fig. 16). Wetland Birds While many of the bird species that use wetlands are able to live in other habitats as well (e.g. red- winged blackbird), the 3 1 species listed in Table 1 1 are dependent on wetlands and their presence serves as an indicator of wetland conditions. Although at least 15 wetland-dependent species occur in southern Illinois and at least 27 Figure 16. The percentage of non-natii>e plants* at CTAP wetland sites, by layer and region * the ground layer is measured hy the cmvr of the plants, the shrub layer by the number of stems, and the tree layer by the basal area species occur in the north, a statewide average of only 1.3 wetland-dependent species per site was detected at the 50 sites censused in 199" and 1998. No wetland-dependent species were detected at half the sites, and only 16 of the 31 wetland-depen- dent species were detected; only six species were found in at least 10 sites. Twelve of 35 state threatened or endangered bird species are wethmd- dependent.yet only three were detected, at one site each. Tlieir rarit)' ftirther reveals the degraded condition of the average wetland in Illinois. Ecosystem Monitoring Results 25 Table 11. Detection Rates for Wetland Birds Bird Species* Illinois Status Detection Rate Geographic (% of Sites) Distribution Pied-billed grebe Threatened 2% Statewide Double-crested cormorant 2% Statewide American bittern Endangered not detected Mostly northern IL Least bittern Tlireatened 2% Mostly northern IL Great blue heron 24% Statewide Great egret 6% Statewide Snowy' egret Endangered not detected Southern IL only Little blue heron Endangered not detected Southern IL only Cattle egret 2% Southern IL only Green heron 4% Statewide Black-crowned night-heron Endangered not detected Statewide Yellow-crowned night-heron Endangered not detected Southern IL only Mute swan not detected Northern IL Assessment The habitat quality index, modified from the United States Environmental Protection AgencN; provides a numerical measure of human induced physical disturbance as well as the abUirs" of the stream to provide hiding and feeding places for aquatic organisms. CTAP scientists score 12 habitat para- meters that relate to the quality' and width of shoreline vegetation, quantity and quaHr\' of in-stream cover (e.g. coarse mineral and organic substrates and undercut banks), the condition of banks, and relative straightness of the stream course. The index provides a numerical score, rang- ing from zero to 180 points, that increases with stream quality. Actual scores ranged from 25, indi- cating severe landscape and drainage alterations, to 146, indicating an aquatic and riparian resource of the highest quality; The statewide average was 88.6. indicating that the average stream in Illinois displayed only fair habitat qualit)'. Most Illinois streams lack natural habitat features such as wooded riparian (streamside) corridors, winding stream channels (many are channelized), and stable in-stream habitat such as coarse rocks and wood debris (often removed to improve drainage). Highh' agricultural ISIS basins, including the KankakeeA ermilion N./Mackinaw, the Kaskaskia, Rock, Spoon, and Embarras/ Vermilion S. watersheds, scored below the statewide average for habitat qualitA- (Fig. 20). Streams in these areas have been modified to drain row crop fields nipidh'. Tlie Sangamon and Little Wabash basins, on tlie other hand, scored higher than the statewide average because more of their streams are larger and flood-prone, discouraging row crop agriculture close to the streams. Aquatic Insects/Benthic Macroinvertebrates Icixa Richness: llie EFT taxa richness index mea- sures the number of EPT t;ixa (species relatively Ecosystem Monitoring Results 31 intolerant of pollution) present in a sample — higher index values indicate less organic pollution. EPT are most diverse in natural streams and decline with increasing watershed disturbance. EPT rich- ness ranged from zero to 17, suggesting that stream health ran the gamut from poor to excellent across the 59 sites sampled by CTAP scientists. Statewide, the average was 7. 1 EPT taxa per stream, indicating that most streams were in only fair condition. Figure 22. Distribution of EPT taxa richness, RiverWatch ISIS basins with the lowest EPT score (impl)'ing poorest condition) were the Kaskaskia and KankakeeA'ermilion N./Mackinaw watersheds. These are highly agricultural areas that offer extremely monotonous habitat for EPT species. Alternatively, the EmbarrasA'ermilion S., Spoon, and Sangamon watersheds had the highest EPT richness (Fig. 21). The Rock River watershed was historically one of the richest for EPT species in the state. Currently, it supports less than the statewide average. The average EFF taxa richness at RiverWatch sites was 2.6, much lower than the CTAP average because RiverWatch collects only nine EPT taxa. RiverWatch EPT taxa richness reached a high of 2.9 in 1999. although this followed a low of 2..^ in 1998; no clear trend is discernible. The Spoon, Big Muddy/Saline/Cache, Kankakee/Vermilion/ Mackinaw, and Embarras/Vermilion watersheds fared better than the average. At the opposite end of the spectrum were the Kaskaskia, Little Wabash, and Fox/l)es Plaines watersheds. Figure 22 shows the distribution of EP'F taxa richness for all KiverWatch .samples. 160 - 140 120 ; 100 1 i^ 80- I I T T d 1 I : T I p; I 3: 20 Figure 20. Distribution of ai'era^e habitat quality scores statewide and for 10 ISIS watersljeds Note: sqimres indicate the mean, the horizontal line in the hox indicates the median, bay denotes 25-75 percentiles, while ivrlical lines denote lO-'X) percentiles Number of ob.ten'ali-= 1 E u Figure 21. Distribution ofareraf^e I:PT ta.xa richness statewide and for 10 ISIS watersheds Note: squares Indicate the mean, the horizontal line in the bay indicates ll.w median. IIjc box denotes _'5-~5 percentiles, while ivrlical lines denote IO-')() fiercenllles. Number of observations an- iiulicalcd aboiv calef;iirv labels. 32 Critical Trends in Illinois Ecosystems 1 5+ taxa 0-2 laxa 3% /--pa 2% 3-5 taxa 11% n-lStaxa / / \ ij \. 25% / 1 J 1 f f 6-10 laxa ' 59% Figure 23. Distribution of total taxa richness, RiverWatch Total taxa richness, calculated for RiverWatch sites, specifies the number of distinct taxa identi- fied at a stream site — a more diverse array of taxa indicates better stream health. Taxa richness aver- aged 8.9 taxa per sample overall. More than one-fourth of samples had 1 1 or more taxa, nearly three-fifths had from six to ten taxa, and one-eighth had fewer than six taxa. The highest taxa richness was found in the Spoon, Big Muddy/Saline/Cache, and the Embarras/Vermilion watersheds. The lowest average taxa richness was recorded for the Kaskaskia and Little Wabash watersheds. ta 1= o j: ' e X 7-p- 6.5- -p j- 1 -n - T- - 6- 5.5- 1 r ■ r- I ■ r- L 5- ■ _ iJ -^ rn 1 ^ 4.5 - 4- -p - _ P -|- * - - r ■ y 3.5- 3--5 ^ r— ' r-- r-' r^ r^" r-' r-' r^ r-' ^ * a s .Q ?i 1 h in BQ u s J Figure 24. Distribution of avera}>t' HBI scores statewide and for 10 ISIS ivatersheds Note: squares indicate tin' menu, the Ijorizoiital line in tlte hikv iniliailes li>e incilian. lite bfix denotes 25-75 percentiles, while vertical lines denote l()-')0 percentiles. ,\nniher of observations are Indicated abotv category labels. Indices of Organic Pollution: The Hilsenhoff Biotic Index (HBI), developed by aquatic biologists in Wisconsin, provides an overall index of pollution tolerance for an EPT sample. De\"eloped as an Index of organic enrichment (livestock and human wastes entering streams), it also detects multiple forms of watershed disturbance. Indi\idual species tolerances range from zero to 10. with higher num- bers indicating greater tolerance to disturbance. The index measures the weighted-average pollu- tion tolerance value for all EPT taxa in a sample — a lower score indicates better stream qualit)'. HBI scores at CTAP sites ranged from 3-1. indicative of a healthy stream, to ~.l. which suggested moderate-to-severe organic enricliment and disturbance (Fig. 24). Statewide, the average score was 5.2, demonstrating that streams were moderately impaired and had EPT fauna that were moderately tolerant of organic pollution and overall stream disturbance. Relativeh' few streams had taxa intolerant of these conditions. Streams that dis- played the lowest scores were in the Spoon River basin and those with the highest HBI scores were in the Rock River basin. The Macroinvertebrate Biotic Index (MBD. modified from Wisconsin's family level HBI toler- ances, provides a weiglited-average of the pollution tolerance of organisms in a RiverWatch sample. If poUution-intolerant t;ixa such as stoneflies are found in a stream, it indicates that organic pollution is low or modest. On the other hand, if the stream is dom- inated b) pollution-tolerant taxa such as aquatic worms, the stream is probably polluted. RiverWatch MBI \alues axeraged S."^ over the tour-year period 199S to 1999 (Table 13). Values declined from 63 to S.5 during this time, suggesting improved qualitx; but the decline may have been an artifact of improved training. Southern Illinois has some of Illinois' least disturbed habitats, so it is not surprising that the Big Mudd)/Cache/Saline watershcil h.id one of the lowest five-year averages, as did the Spoon. The Sangamon, KankakccA'crniilion N./Mackinaw, and Rock \\ atcrslieds aLso iiad bcttcr-tiian-average .MBIs. The Little Wabash basin had tlie \\c)rst MBI, fol- lowed b)' the EmbamisA'ermilion S., Kaskaskia, and Fox/Des Plaines w atcrsheds. I J Ecosystem Monitoring Results 33 Table 13- MBI:Mean, Standard Deviation, and Range Mean Standard High Deviation Low 1995 6.3 1.7 10.8 2.7 1996 5.7 1.0 9.9 1.3 1997 5.8 1.2 11.0 2.4 1998 5.6 1.1 11.0 1.7 1999 5.5 1.0 9.7 2.0 Overall 5.7 1.2 11.0 1.3 Taxa Dominance: Taxa dominance, calculated for RiverWatch, measures the percentage of the three most common taxa compared to the rest of the sample. Dominance by just a few taxa indicates lower stream quaUt)'. Taxa dominance averaged 80.4% statewide, with ISIS watershed averages ranging from 77.2 to 85. 9%. The Spoon and the Big Muddy/Cache/Saline watersheds had the lowest taxa dominance, demonstrating better health. The Kaskaskia, Little Wabash, and LaMoine showed the biggest problems with taxa dominance, indicating that they were the least healthy. Six taxa are most often associated with taxa dominance in Illinois streams — sowbugs, caddisflies, midges, scuds, black flies and mayflies (Fig. 25). Olher ^ 23% ^^ 1 Sowbugs ^"~~-^^^ 17% i ^^^ Caddisflies 15% Mayllies \ f ^^~-3^» Black llies ^ 10°0 L ^^^r Midges ScuU S Fishes Fish species, due to their greater mobility, tend to indicate envirormiental changes on a watershed scale. Total native fish species richness, fish species dominance, and the number of exotic and hybrid species are used as indicators of watershed disturbance. CTAP scientists sample fishes in randomly selected small streams — 30 CTAP sites are sam- pled each year with a total of 150 sites sampled over a five-year period. They also obtain samples from IDNR fisheries biologists who focus on larger streams. The IDNR fisheries samples are gathered from 514 stations in all 33 hydrologic units in Illinois over a five-year period. Approximately 160 IDNR fisheries sites are sampled c%'er)' \ear 'III '-t: 'l ^' mm Fish Species Richness: Illinois has a rich diversity of fishes: 188 native species that include colorful darters and the unique ancient fishes — sturgeon, paddlefish, and gars. Each species differs in its sensitivity to various types of environmental disturbance, and some species are quickly lost when ecosystems are disturbed. From earlier studies, we know that 1 1 native fish species have been extirpated from the stale since the turn of the centur)'; currently there are 31 species on the state's list of threatened and endangered species. The statewide average for native fish richness is 13.6 species at the 58 CTAF fish sites sampled in 1998 and 1999. The Embarras ba.sin is by far the richest, while basins that supportetl the fewest species are the bi.Moine and the Spoon (I-'ig. 26). Elet>en native fish species have been extirpated from the state since the turn of the century. Figure 25- Most common macroinvertebrates sampled by RiverWatch 34 Critical Trends in Illinois Ecosystems I ^. I I J 1 is S g Figure 26. Distribution of average native fish species richness statewide and for 10 ISIS basins Note: squares indicate the mean, the horizontal line in the bixx indicates the median, the bar denotes 25-75 percentiles, while vertical lines denote 1 0-90 percentiles. Number of observations are indicated above category labels. Fish Species Dominance: Streams that support large numbers of a relatively few species, as opposed to those with low-to-moderate numbers of many species, are generally thought of as being degraded. Moreover, in cases where one or a few species are abnormally dominant, those species are usually disturbance-tolerant. When the number and quality of microhabitats (pools, riffles, undercut banks, stable sand bars) are reduced it tends to eliminate habitat specialists, leaving behind mostly habitat generalists. For instance, when sedimenta- tion becomes severe the variability of pool depth decreases while the expanse of shifting sand bottom with shallow water overhead increases. Species such as the sand shiner and bluntnose minnow, habitat generalists, often become dominant in this situation. Of the seven IDNR basins surveyed. Salt Creek — a large tributary of the Sangamon River — has the largest percentage of the three most abundant fish species (Fig. 27). This basin receives tremen- dous quantities of water because much of the watershed is tiled. The increased runoff has eaten away at banks, making the streambed wider, and deposited tremendous quantities of s:md and silt, promoting extremely high numbers of red and sand shiners and bluntnose minnows, all habitat generalists. The Vermilion River watershed in eastern Illinois also shows high dominance, despite the Middle Fork being a designated National Scenic River. The western drainage is highly agricultural and has been degraded due to sedimentation, sewage discharge and cattle grazing in the earh' 20th centur>'. The drainage is dominated by a relatively few species including bluntnose min- nows, striped shiners, and longear sunfish. all habitat generalists. Although one might consider the Vermilion River and Salt Creek to be in better condition based on their higher species richness, this pattern of abimdance suggests the communities are out of balance. Figure 27. Tlie relative proportion of the three Diost abundant Species sampled in each of seven IDNR Fisheries watersheds and the CT.AP statewide at>erage Note: the number of samples are in parentheses Diversity and abundance of hybrids and exotic species: Many exotic (non-native) fish species and hybrids (crosses between different species) have been released or escaped into Illinois streams. Since the 1880s, 15 exotics have been recorded in the state. Occasionally these taxa thrive and become dominant components of fish commu- nities, often at the expense of native species. Moreover, many exotics and hybrids thrive under disturbed conditions and their presence can be an indicator of stress. Wlaile hybrids are few in number across the IDNR fisheries basins as well as CTAP sites, exotics are relativeh abundant in the Des Flaines and Pecatonica basins cFig. 28). Ihe Des Flaines watershed is highly urbanized, while a large i Ecosystem Monitoring Results 35 CTAP StalewKJe (58) ■ 1 Pecalonjca River (10) ^ ^ Rock River (15) KaskastuaRrvef(l5) ■^^1 ^^^1 ■ - Dos Plaines River (19) Kishwaiikee Rivw (17) Vermilion RrverS. (14) Salt CreeK (18) " ^ ■ 2% 3% 4% 5% 6% 7% 8% 9% Figure 28. Percentage of exotic species at seven IDNR Fisheries basins and the CTAP statewide average. Note: the number of samples are in parentheses dairy industry is located in the Pecatonica watershed. The Kaskaskia basin, on the other hand, supported the fewest exotics even though it is a highly modified, agricultural basin. CTAP monitoring suggests that exotics are of relatively minor importance, but this may be a consequence of the program's random sampling design and its focus on smaller streams than those sampled by IDNR Fisheries. Small streams often have fewer exotic species than large ones. Although water quality' is likely to improve, the abundance of exotic species is unlikeh' to decrease soon. For example, grass, bighead, and silver carps have been recently introduced; all have the capacity to outcompete many of our native fish species and to alter habitat by uprooting aquatic plants, thereby increasing turbidity. Conclusion Streams in Illinois have experienced drastic modification over the past 150 years. Most streams that drain prairie landforms have been straight- ened, their canopies removed, and their watersheds tiled to drain fields more rapidly. Historical data confirms the lo.ss of several fish, mussel, and aquat- ic insect species from what was a very diverse aquatic setting. Habitat quality scores most readily confirm this degradation. Water chemistr> "snap shots" demonstrate that centers of high human population density and agriculture have changed the chemical signature of streams through the release of effluents and the loss of riparian vegetation. EPT and fish communit>' characteristics demonstrate some drastic differences across ISIS basins in the state. Table 14 summarizes the picture presented by CTAP scientist and RiverWatch volunteer data. It shows the importance of using multiple measures of stream quality' — no watersheds scored high on all of them. The Spoon River, for example, scored high in all measures of macroinvertebrate diversity- and pollution tolerance — its streams have a diverse macroinvertebrate community that is gen- erally intolerant of pollution. On the other hand, the watershed has only average habitat quality' and below-average fish diversity. The Embarras/ Vermilion S. watershed has both diverse macroin- vertebrate and fish communities, but poor HBI and MBI indices — the organisms are tolerant of pollu- tion. Several watersheds scored near average or below average on most indicators, including the Rock, Fox/Des Plaines, and LaMoine. The Kaskaskia watershed scored consistently low on virtually' every indicator r\ ^\ ':iX^')^''M:\ ^7n\ jA/ 'ii '' ,^ / ■ I 1^^" '^^Wm ^^^ ^^' ■ W^^jT r)^ / iWtSm^-^^k X i*S^!'^ W^% -^^j^^^^F^^I vmL /■ r^^^n^H ^S^i Jy^'m^'^^^ ^tN*. 1 ""^ '^^i& \a/ m' " r '' ' JrffjL v^^.ln^ Aa^^^BI T^ '\~^ ' w^inH njtOjjfegB -^''^^fl^^^^^^l MB^Lj^A AT^ jy^ei^^'^j^HH In a couple ol instances, llic \i)lunteer and pro- fessional data seem contradictor^'. In the case of the Little Wabash watershed very few sites were moni- tored, so more data is needed before stream quality can be judged. In the Big Muddy/Saline/Clache, ClAP scientists found the quality' to be below average, reflecting that several of their randomh' selected sites were in the intensively farmed Big Muddy and Saline basins. RiverWatch volunteers mostly monitored streams in the Cache basin or Shawnee Forest, and the stream quality indicators illustrate the relatively pristine nature of this area. 36 Critical Trends in Illinois Ecosystems Table 14. Basins with Notably Better or Worse Indicator Values Relative to the Average Most streams that drain prairie landforms have been straightened, their canopies removed, and their watersheds tiled to drain fields more rapidly. HBI MBI EPT EPT Taxa Taxa Native Darter Exotic Habitat Richness TaxafRW) Richness Dominance Fish Richness Species Score Rock - + - - Fox/Des Plaincs - " - + KaakakeeA'ermilion/ Mackinaw + - + + + - - Spoon + + + + + + - + Sangamon + + - + + + LaMoine - - - + + Kaskaskia - - - - - - - - - EmbarrasAfermilion - - + + + + + + Little Wabash + - - - - + + + + Big Muddy/SaUne/ Cache - + + + + + - Note: Blank cells indicate values near the average, '+ ' indicates greater than 1/2 standard deviation above the average, '-'indicates more than 1/2 standard deviation below the average. CORRELATING AQUATIC INDICATORS CTAP uses several aquatic indicators to monitor stream quality. The most valuable indica- tors are those that contribute unique information about stream quality and are also correlated with other indicators. The table below shows where relationships between indicators are strongest. For example, EPT richness is significantly corre- lated, in a negative fashion, with the HBI; RiverWatch EPT taxa richness is similarly corre- lated with the MBI. This fits the hypothesis that when water quality is good, the number of EPT taxa should be higher and the HBI and MBI should be lower since many organisms are present that are less tolerant of pollution. >X^ile the correlations confirmed this rela- tionship, sampling results did not always fit this model. A sampling site may have high EPT richness, indicating species diversity, while the HBI value reflects a large number of pollution tol- erant organisms. ()ne explanation is that Illinois streams are so degi~aded from a century of abuse that relatively few sensitive EPT taxa remain, par- ticularly in the northern three quarters of the state. In the future, any increase in EPT richness will most likely result from the homogenization of moderately tolerant taxa across the state, not from colonization of sensitive taxa from distant "islands" of high quality' habitat. Several indicators are correlated with habitat quality, wliich is surprising since other attempts at this have been difficult — the paucit)' of "pristine" habitat has left only a partial range of habitat quality from which to detect relationships. EPT ricliness ;md darter rich- ness are both positively related to the habitat score, indicating that better habitat supports greater biodiversit}-. The mmiber of exotic fish species is negatively correlated with habitat, since the niunber of exotic species ;ire expected to be higher when habitat is poor. Several of the other RiverWatch indicators also show significant correlation. EPT taxa rich- ness is correlated with tot;d taxa richness and taxa dominance, and taxa domin;uice and taxa richness are also correlated with one another. More than half (53%) of the variation in taxa Htosjstem Monitoring Results 37 Significant Relationships Ainong Aquatic Indicators Comparison Correlation P # of observations HBI vs. EPT richness -0.3.^ 0.01 57 MBI vs. EPT taxa (RW) -0.42 <0.01 1178 Habitat score vs. EPT richness 0.28 0.04 57 Habitat score vs. Darter ricliness 0.35 <0.01 58 Habitat score vs. Exotic species -0.28 0.04 58 EPT taxa (RW) vs.Taxa richness 0.68 <0.01 1178 EW taxa (RW) vs.Taxa dominance -0.53 <0.01 1178 Taxa dominance vs.Taxa richness -0.73 <0.01 1178 Native fish vs. Stream width 0.48 <0.01 58 Native fish vs. Darter richness 0.57 <0.01 58 pH vs. Conductivit)' 0.28 0.02 68 pH vs. Dissolved oxygen 0.47 <0.01 68 Note: The closer the correlation coefficient is to one, the stronger the relationship. A negative sign indicates that as one variable increases the other deaeases. p is the probability the relationship is due to chance. dominance is explained by variation in taxa richness (and vice-versa). Thus, when a stream suffers from taxa dominance (that is dominance by just a few taxa), it generally has a lower over- all taxa ricliness. It is not clear whether the RiverWatch indicators are correlated with habi- tat quality because the volunteers have not calculated a habitat score. A habitat index is being developed and its relationship to other indicators will be explored in the future. Native fish species richness is positively correlated with all other fish richness measures, as well as fish abundance and stream width. Thus, larger samples and larger streams generally yield more species of fish (natives, minnows, and darters). The latter suggests that stream biological criteria may have to be scaled for stream size. Water chemistry parameters do not seem to be significant!) correlated to most biological indicators, althougli some water chemistry indi- cators are correlated among themselves. Conductivity is positively correlated with pH, since greater dissolved ions in water from human or bedrock sources usually leads to a higher pH. Dissolved oxygen is also strongly correlated with pH. Streams receiving an abnormally high amount of sunshine develop algal growth and increased photosynthesis, which leads to an increase in pH by removal of hydrogen ions from the water. This seems innocuous, but the increased photosynthesis is a telling feature of streams that iiavc had their tree canopy removed, a condition that leads to increases in maximum water temperature and to drastic changes in the food quality and quantity available to aquatic organisms. Streams shift from a food ccononi}' based on tree leaves, to one where filter-feeding on small particles j grazing on algae predominates. >, to and ■ J 38 Critical Trends in Illinois Ecosystems CHAPTER FOUR Rock River Watershed Significant features include upland and floodplain forests, seeps, springs, prairies, aquatic systems, cliffs and bedrock outcroppings. Illinois' third largest ISIS watershed is located in the northwestern part of the state. It has the most grassland acreage in the state, as well as the highest percentage of land in grasses. The Rock is the third most urbanized watershed (in both acreage and percentage of land), with only the Fox/Des Plaines and Kaskaskia water- sheds being more urbanized. (See page 103 for a color map of the watershed's land cover.) Five sites within the watershed have been designated as Resource Rich Areas (RRA) — the Driftless Area, Kishwaukee River, Rock River, Sugar River, and Mississippi-Lower Rock River. • The 300-square-mile Driftless Area RRA is a unique part of the state because it escaped Pleistocene glaciation.The area is characterized by rolling hills and wooded ridges and includes canyons, ravines, bluffs and palisades. Some of the flora and fauna are distinctive and unique in the state, including several plant species which are northern species or preglacial and inter- glacial relicts. • The Sugar River RRA is characterized by a wide, wooded riparian corridor of floodplain forest and upland woods. The smallest RRA at 23.7 square miles, the area is along an imponant bird migration route and provides habitat for several unusual amphibians and reptiles. • The natural resources of the 101-square-mile Kishwaukee River RRA are concentrated along the wooded corridor of the river. Original!) the area was savanna with many sloughs and marshes, but is now primarily agricultural. • The Mississippi-Lower Rock River RRA encompasses ^15 square miles — 81% in the Rock River watershed and 19% in the Spoon River watershed. It includes major rivers, bottomlands, upland forests, prairies and ri\er bluffs. The area has a relatively high total acreage of natural areas because of the Mississippi River sites. The ecological core of the 322-square-mile Rock River RRA is the river corridor from Rockford to Dixon. Significant features include upland and floodplain forests, seeps, springs, prairies, aquatic systems, cliffs and bedrock outcrop- pings. Some of the habitats support relict boreal plants which are more normally found farther north in Wisconsin and Mirmesota and in the Appalacliian Mountains. Table 15. Watershed Land Cot>er Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest 297,383 7.3% (8) Grassland 1,073,788 26.2% (1) Non-forested wetlands 37,092 0.9% (5) Bottomland forest 49,663 1.2% (8) Water 63,506 1 .6% (4) Urban/built-up 175,492 4.3% (3) Cropland 2,398,071 S8.6"o (8) Total acreage 4,094,998 100.0"o 7.2% (5) 16.7% (1) 10.5% (5) 5.7% (8) 12.7% (4) 9.4% (3) 11.1% (5) 11.3% (3) * The ivatershed's percentage of the land cotvr type statewide, e.g. 7.2% of the state's upland forests are located in this watershed. Note: the watershed's rank (1st- 1 0th) is shown in parentheses. Rock River Watershed 39 ECOSYSTEM MONITORING CTAP biologists assessed eight streams in this watershed. The region had the worst average HBI score of all watersheds, indicating that its streams were the most organically enriched. Since the watershed is heavily grazed by livestock, the HBI average is not surprising. The Rock also had lower than average EPT richness, fish richness, and habitat quality-. While historically it was one of the richest watersheds in EPT and native fish species, the loss of vegetated riparian zones, stream channelization, siltation, and livestock grazing have taken their toll. The best stream sampled was Elkhorn Creek near Milledgeville. It had a habitat score well above the state and basin average, but it also had a rela- tively low native fish richness. The worst site was Coal Creek near Mineral in Bureau County. It had recently been dredged, so the bottom was mostl) clay overlain by loose sand and silt. It yielded just two EPT taxa and habitat quality' was ver>' poor due to channelization, lack of variation in depth, and lack of canopy. However, native fish richness was relatively high for such a monotonous habitat. RiverWatch collected 179 samples at 75 sites on 50 streams between 1995 and 1999. Its bio- logical indicator data also suggest that the Rock River watershed is of slightly below-average Table 16. Watershed Indiccitor Scorecard Indicator Watershed Value Statewide Value Watershed Ranking Macminvertebrates HBI 5.8 5.2 10 MBI 5.5 5.7 4 EPT richness 6.4 7.1 7 EPT taxa (RW) 2.7 2.6 6 Taxa richness 8.8 8.9 7 Taxa dominance 8().2% 80.4% 6 Fish Native fish 13.0 13.6 6 Darter richness 1.7 1.9 8 Exotic species 0.5 0.2 10 Habitat Habitat score 80.5 88.6 8 ecological quality' (Table l6).The watershed ranked near the median in MBI and EPT taxa, both indicators of organic pollution. Taxa richness and taxa dominance are also slightly below average, showing lower diversity' in macroinvertebrates than other watersheds. Midge larvae, scuds, and h>'drop.sychid caddisfly larvae were the three most dominant taxa overall. Each is among the state's most conmion macroinvertebrates. Tiible 11. MBI Values statistic 1995 1996 1997 1998 1999 OveraU Average Standard deviation Minimum Maximum Number of sites' 6.07 5.52 5.60 5.41 5.24 5.46 1.19 0.65 0.97 0.82 0.89 0.89 4.10 4.34 4.20 4.30 309 309 7.63 6.81 8.87 7.67 7.68 8.87 9 28 41 49 46 173 * Only stimples with at least 25 organisms were included in the analysis. Statistical analysis did not detect any major trends in MBI (Table 17). Values decreased over the five years, suggesting improved stream quality, but the change is not statistically significant and was probably exaggerated by blood worm identification errors in 1995. H CTAP - INHS River Sites (ii RiverWalch Sites A ForestWatch Sites Figure 29. Monitoring sites 40 Critical Trends in Illinois Ecosystems The basin supports nearly 800 native plant species, or 38% of the species native to Illinois. REGIONAL ASSESSMENTS Five regional assessments have been completed for the Rock River Watershed — for the Upper Rock River Basin, Lower Rock River Basin, Kishwaukee River Basin, Sugar-Pecatonica Rivers Basin, and the Driftless Area. Upper Rock River Basin The Upper Rock River covers nearly 640,000 acres (999 square miles) in north central Illinois. It consists of eighteen sub-basins between Rockford and Sterling that drain into the Rock River. It is typical of agricultural Illinois — rolling, rural, prosperous — except for the rocks. Bedrock has been pushed to the surface here. Exposed rock forms canyons, bluffs, and ravines. Where it has been crumbled by weather it creates unusual soils, which foster the develop- ment of equally unusual natural communities. Agriculture is the dominant land use in the area, as it is across most of the state. Sixty-one per- cent of the area's acreage is devoted to croplands, slightly above the state average. Grasslands (mostly pasture, but also prairie, rights-of-way, and such) account for 23%, compared to 18% for Illinois. Forests and woodlands are the next-largest category with 8%, which is below the state average of 11%. Forests are concentrated on the uplands along the Rock River and its major tributaries. Urban and built-up coverage matches the state share of 6%. Wetlands and open water combine for less than 3%> of the area, compared to about S.S"{. for the state. The distinctive landscape provides an array of natural habitats: • several of the 33 Illinois Natural Area Inventory sites contain ecosystems of statewide signifi- cance — cliffs, bluffs, soils, and plant life associated with St. Peter's sandstone bedrock that are unique to this part of the state, • 17 miles of streams (segments of the Kishwaukee and Rock rivers) have been designated as Biologically Significant, 206,215 acres have been designated a state Resource Rich Area. the Castle Rock State Park/Lowden-Miller State Forest complex is home to more breeding pairs of forest bird species (85) than any other part of Illinois. defg ■ A Cropland (60.6%) c D B Grassland (22.9%) ^H^B k DC Upland forest (7.9%) ^l^^l ^ ■ D Urban/built-up (5.8%) "^I^H ^^ ■ E Water (1.5%) B ■ J ^^ ■ F Bottomland forest W (0.8%) W f^ D G Non-forested wetlands (0.4%) Figure 30. Upper Rock River basin land cover Plant and animal life The basin supports nearly 800 native plant species, or 38% of the species native to Illinois. Thirt>-eight plants are listed by the state as threatened or endangered. The prairie bush clover is also on the federal list of threatened species. Over h;ilf of the area's threatened or endangered species are associated with the St. Peter's sandstone bedrock and its derivative soils. Basin acreage - 639.479 acres State land* - 5,303 acres Total natural areas - 6,020 acres High-qualit>' natural areas - 200 acres Nature preser\es - l.OSO acres * Ck>es not include natural areas or nature presents that may he state owned. The area has high terrestrial species diversity- due to the range and extent of habitats. Birds account for the vast majoritv' of state threatened and endangered species (T&E): the rixer otter is the soleT&E mammal. Among reptiles and amphibians, the four-toed salamander, western hognosc snake, and Blanding's turtle are listed as T&E species. Nearly all reptiles and amphibians that existed in the area before European settiemeiit are still present. Three T&E fish species and fi\e mussels have been recorded in the area, but their continu- ing presence is unlikety. Rock River Watershed 41 Local economy and outdoor recreation The tliree main counties in the Upper Rock River basin — Winnebago, Lee and Ogle — account for 3% of Illinois' population and 2.5% of its personal income. Winnebago County accounts tor 80% of the area's economic activity'. Following national and state trends, the area economy has sliifted towards the service sector — between 1969 and 1993, employment in the services sector grew from 14% to 29% of total employment, while employment fell from 39% to 24% in the manufac- turing sector. Tlianks to higher wages, however, manufacturing remains the largest sector in terms of earnings. Outdoor recreation opportunities in the area are driven largely by the Rock River itself. The Rock is among Illinois' finest fishing streams — especial- ly tor walleye and catfish — and boat access is offered at 39 points. Nearly 9,200 acres are publicly owned, accounting for about 1.5% of the total area. Lowden-Miller State Forest is the largest state site, closely followed by the adjoining Castle Rock State Park. The area's five major state sites attracted nearly 1 million visitors in 1994 and created 250-300 jobs. Threats ■While the Upper Rock River area's ecology is impressively diverse, it nonetheless faces threats common to Illinois including habitat fragmentation and degradation, stream alteration, and erosion. Habitat degradation and fragmentation - Before settlement, more than one-third of the land was prairie and the remainder was forest. Today, 48 acres (0.02%) of presettlement prairie remains, and 9% of the area remains forested, with 114 acres considered high qualit)'. Remaining habitats are often carved up into habitat 'islands', which may not be able to sustain healthy ecosystems over the long run. Large nianimais aiul other far-ranging species lack adequate habitat, and the small popu- lations of plant and animal species that do live here are vulnerable to di.sca.se, drought, and a lack of genetic diversity. Most of the original habitat was displaced by agriculture, but urbanization is now a noticeable trend. In some former agricultural regions in Illinois, such a.s the Fox and DuPage ri\er valleys, subdivisions, malls, and office parks have largel)' replaced farms as the dominant features in the landscape. The same economic and social forces are now pressing on the Upper Rock River area, accelerating fragmentation. Stream alteration - Dams and lc\ L■c^ iiave been built along the Rock l^ver for flood control and electricity generation. Unfortunately, they also raised water temperature, slowed the current, isolated tlsh and mussel populations, and generally disrupted wildlife that had adapted to the natural cycles of the river Erosion - The hilly, heavily farmed Rock River basin has been subject to erosion, which costs farm- ers valuable soil and leads to increased siltation in streams and rivers. This in turn can choke off vege- tation and fi.sh nests, impede fish that depend on their sight for survival, and carry pesticides and fertilizer into streams. During the 1930s and 1970s, erosion in the form of gullying was particularly severe. Today, however, only 25%i of the land is considered "moderately" eroded, and siltation has decreased since the early 1 980s.The change may be due in part to more farmers using conservation tillage and .setting aside erodible land In response to federal incentives. Opportunities Many of the changes that humans have made are reversible. For example, controlled burns can kill off tree seedlings sprouting in prairie sod the wa)' that lightning fires used to. and dismantling drainage structures can put the "wet" back into wetlands. If the ilanis cannot be removed along ilie Rock River, the) should at least be modified to include chutes that both fish and canoeists can use to move up anti ilow n the river The basin has .several large, contiguous habitats that serve to mitigate the jiroblems of In some former agricultural regiotis in Illinois, subdivi- sions, malls, and office J)arks hat'e largely replaced farms as the d(miinant features in the landscape. 42 Critical Trends in Illinois Ecosystems The amount of potentially restorable natural land in the area is sizable. fragmentation. The most significant is the Castle Rock State Park/Lowden-Miller State Forest complex. Most of the 4,225 acres are forested, pro- viding one of the finest bird habitats in Illinois. Large tracts like this offer certain birds protection from competitors and predators that frequent the forest edge, such as the cowbirds that parasitize native songbird nests. The amount of potentially restorable natural land in the area is sizable. For example, several dozen acres of restorable prairie persist within a golf course maintained by the Byron Forest Preserve District. The Nachusa Grasslands offer similar potential as a large prairie. The Nature Conservancy site now includes more than 1,000 acres. The Conservancy intends to protect the existing patches of prairie and restore as fully as possible the fields separating them. Ultimately, the plan is to connect Nachusa to Franklin Creek State Park, maximizing the amount of contiguous wildlife habitat. Lower Rock River Basin The Lower Rock River Basin encompasses 2,543 square miles (1.6 million acres) in northwestern Illinois, including substan- tial parts of Bureau, Carroll, Henry, Lee, Ogle, Rock Island, and Whiteside counties and slivers of DeKalb and Mercer counties. The bulk of the area consists of that portion of the Rock River's drainage area that lies between the DeKalb/Lee count)' line and the river's confluence with the Mississippi River near Moline. Agriculture is the dominant land use with 87.5% of the land cover — high even b)' Illinois standards. More than 75% of the agricultural land (68% of the total) is dedicated to crop land (mostly row crops, but also small grains and orchards). The remainder consists of rural grasslands, which include pastures, alfalfa and other ha)', rtiadsides, remnant prairies, and other grassland cover in rural areas. Little of the area's presettlement natural habitats remain. Less than 0.001% of the area's ecosystems are considered high qualit)-, compared to 0.07% statewide. Most of the native prairie was plowed; only 0.002% of presettlement prairie survives. Channel dams have converted the Rock River into a series of lakes, and the rich complex of wetlands, once the area's most distinctive ecological asset, has long since been drained and converted to crop land. Basin land - 1,627,442 acres State land* - 10,012 acres Federal land - 675 acres Total natural areas - 9,255 acres High-qualit)' natural areas - 154 acres Nature preserves - 445 acres * Does not include natural areas or nature preserves that may be state owned. Even so, the area's varied topograph) supports a wide range of ecological communities, wliich in turn support an impressive variet)' of species, and largely compensates for the relative scarcit)^ of high-qualit)' habitat. Ke)- features include: • 44 miles of streams that ha%e been designated Biologically Significant because of their fish or mussel diversit)'; • 43 Illinois Natural Areas Inventor)- sites that include marshes, seeps, two r)pes of forest, and eight r)'pes of prairie; and • Nachusa Grasslands, a l.OOO-acre prairie restoration owned by The Nature Conser\-anc)-. EFG ■ A Cropland (68.8°o) H B Grassland (20.0°o) D C Upland forest (4.7%) D D Urban/built-up (3.6%) ■ E Water (1.4%) ■ F Bottomland forest (0.8%) D G Non-forested wetlands (0.7%) Figure J/. Lower Rock Rifcr basin hitul coivr Plant and animal life An estimated 1,180 plant species can be found in the Lower Rock River area, rouglily 80% of which are native to Illinois. Overall, 39% of Illinois' plants Rock River Watershed 43 can be found here, a high percentage for an area that encompasses only 4.5% of the state. A more thorough survey would probably uncover more species. While high-qualitv' habitat acreage is low, the variety of habitat has nonetheless promoted a good diversity of plant species. Twenty-nine state threatened or endangered plant species are known from the area. Most are restricted to high-qualitA' natural communities, and more than half can be found in sand prairies. More than three-fourths of Illinois' mammal species live in the area, including the state threat- ened river otter Fifteen amphibian and 27 reptile species are thought to exist here, including the endangered mud turtle, the threatened western hognose snake, and perhaps the threatened timber rattlesnake. Although the area supports a large diversity' of aquatic species, some species have disappeared from the drainage in recent decades. With improvements in water quality, extirpated species could conceivably return. Local economy and outdoor recreation Between 1870 and 1990 the population of the five main counties in the basin grew 117% to 330,000, or 2.9% of the state total. By 1994, the area supported nearly 176,000 jobs and generated $4.6 billion in personal income. Rock Island County accounted for more than 50% of the employment and 60% of the income. Since 1970, employment has grown slowly, at 0.4% annually compared to 1.1% statewide. Meanwhile, the economy has shifted towards the service sector, which accounted for 23% of all jobs in 1994 (up from 14% in 1970) while manufacturing slipped from 26% to 17%. Recreational opportunities abound in tlic Lower Rock River area as evidenced by six major state parks and fish and wildlife areas. The 1.5 million visitors at liic state sites generate $16.5 million in economic output and 260 jobs each year More than 800,000 people visit the Hennepin Canal Parkway State Park each year to fisii, boat, canoe, hunt, hike, bike, ride horses, snowmobile, and picnic along the old canal. Part of the Upper Mississippi National Wildlife and lish Refuge is al.so located in the area. Threats While the area contains diverse habitat, its ecology nonetheless faces threats common to Illinois: notably iiabitat fragmentation and degradation, stream alteration, and degraded water ciualit\. Habitat fragmentation and deuradation - Fragmentation, the carving of once-extensive forests, wetlands, and prairies into small habitat "islands" by roads, subdivisions, and farm fields shrinks and modifies habitat. Smaller tracts may not support wide-ranging species, or may support onh' small populations that are more vulnerable to stress, in-breeding, and local extinction. Significant fragmentation has occurred across Illinois, but is particularly problematic in the Lower Rock area. For example, the area's 1,113 parcels of forested wetlands average only 8.2 acres. Few forest tracts are as large as the 500 acres required by many song- birds. Except for the Nachusa Grasslands, most prairie remnants are also too small to support anything approaching the complexity of the original tallgrass prairie. Stream alteration - Apart from the clearing of the prairies, no change to the Lower Rock area has had a more profound ecological impact than attempts to alter the flow of water through it. The draining of area wetlands and the tiling of farm fields increases the amount of arable land, but it also speeds the flow of water into area streams, which then rise to flood stage faster, crest higher, and nin faster (and thus do more damage to stream- banks). In an attempt to reduce Hooding, all but 27 miles of the dreen River has iiecn ilretlged and straightened to increase its water-carrying capacit)'. Erosion and sedimentation - The area's loess soils are vulnerable to the forces of wind and water. Erosion accelerated beginning in the 1920s when area farmers, like their colleagues across Illinois, converted from small grains to row crops, which expo.se more soil. Much of this valuable soil was washed from fields and became sediment in streams, dramatically aflecting stream ecolog}. Fortunately, erosion has been much reduced since the 1980s. Row crop acreage has declined, with most of the region's hilliest, most eroilible land taken out of proiluction through the U.S. Department of Agricultures Conservation Reserve Program. Also, more larmers are using soil-saving More than 800,000 people visit the Hennepin Canal Parkway State Park each year. 44 Oitical Trends in Illinois Ecosystems Many steps can be taken to increase local biodiversity. tillage methods. Today, three-fourths of basin farm- land loses soil no faster than natural processes can replenish it. Water pollution - Two-thirds of the Rock River is now clean enough for the uses to which it is put, according to EPA standards, as is half the Green River Most remaining pollution can be attributed to excess nutrients from partially treated sewage and runoff from farm fields, both of which promote the growth of bacteria that deplete water of oxygen. About 58% of the area is deemed at least "moderately" vulnerable to aquifer contamination, due to geolog- ical factors. However, such pollution is usually local. Opportunities While pristine examples of original habitats either do not exist or are quite small in the Lower Rock River basin, many acres of degraded natural communities persist. These remnants need to be identified, in particular those restorable bits of floodplain forest, mesic (moist) prairie, and savanna of which few or no high-qualit}' examples remain. If they were restored, they could prove crucial to maintaining the biodiversity' of the region. Many other steps can be taken to increase local biodiversity'; the following are just a tew of several recommendations. • Restore grassy and sedge-dominated wetlands to attract threatened and endangered species such as the least and American bitterns, green heron, king rail, and marsh wrens. The Green River Conservation Area in particular would be a likely area for trumpeter swans to begin nest- ing again in Illinois. While there is a paucity of public sites large enough to attract breeding birds, the smaller areas could be managed as stopover sites to attract migrating species such as warblers and vireos. • Leave unmowed strips around ponds to provide refuge for reptiles and amphibians and nesting sites for birds, and dela\ mowing hayfields in which bobolinks nest to spare young birds, since mowing kills as many as 94% of nestlings. • Reestablish streamside grasses, shrubs, and trees to restore the ecological richness of streams. For example, in spite of being sur- rounded by farmland. Fairfield Ditch =1 has clear water because its banks are protected by a sediment-catching buffer of small trees and grasses some ten feet wide. Kishwaukee River Basin The Kishwaukee River originates just south of Woodstock in McHenry County and flows into the Rock River just south of Rockford. The basin covers approximately 1.218 square miles in parts of seven counties. Much of the land is used for agricultural purposes; only 7% is forest or wetland. Glaciation. however, has left moraines, sub-glacial channels, terraces, out-wash fans, valley train deposits, and bedrock highs in the area. The Marengo Moraine is the oldest moraine in the area and is one of the most striking glacial land- forms in Illinois. Though much of the land has been altered for agriculture, unique natural communities remain: • parts of three streams, totaling about fn miles, are recognized as Biologically Significant because they support a high level of mussel and fish diversity, • 64,386 acres have been designated a state Resource Rich Area, • .-^O aci'cs of wetland and 11 acres of prairie are classified as high quality, • the Illinois Water Quality Report rated 86. V\. of the Kishwaukee sulvbasin as "full support." • the Biological Stream Characterization rated the Kishwaukee River upstream from the South Branch as an "A" stream. Rock River Watershed 45 defg ■ A Cropland (66.3%) X^IK ^ DB Grassland (22.1%) . \^ ^ O C Urban/built-up (4.7%) ^^ BD Upland forest (4.1%) ^^1 ■ E Non-forested ^^^^1 ^H wetlands (1.6%) ^^^^^^1 ^V ■ F Bottomland forest ^^^^^^1 ^A (10°°) ^^^ D G Water (0.2%) Figure 32. Kishwaukee River basin land cover Plant and animal species Thim-five percent of the state's native and naturalized vascular plants are found in the basin. Of these, 14 are listed as state endangered and 14 as state threatened. Of these 28T&E species, 17 occur in wetlands. Not all plants found here are wanted or appreciated — 21% of the plants have been introduced from other geographical areas. At least 262 of the 299 bird species that regu- larly occur in the state can be found in the area. Of these 262, 135 breed or formerly bred here, including 14 of the 34T&E bird species. The area's wetlands represent the most significant avian area where species such as the state threatened least bittern and sandhill crane breed. Sevent^'-five percent of the state's mammal species are likel)' to occur in the Kishwaukee area, and the state threatened river otter has recenth been sighted along the south branch of the Kishwaukee River. The basin also supports a diver- sit)- of aquatic species and state endangered fishes include the blacknose shiner and the Iowa darter. Local economy and outdoor recreation The area is home to nearly 5% of the state's popu- lation and is highly urban, with nearly four-fifths of its residents living in urban areas. Since 18^0 the population in the Kishwaukee River area has grown fivefold; growth has been particularly high in Winnebago and iMcHenr\- counties. I'he local econoni) grew nearly twice as fast as in the rest of the state between 1970 and 1994. It generates 4.7% of the state's employment and personal income. In 1994 it employed more than .31 i, ()()() people and generated SI3 billion in income. There are no major state-owned recreation areas in the basin, but conservation districts offer several forest preserves and trails. Tliere are al.so limited activities including hiking and natural histor>' discovery at the undeveloped nature pre- serves and natural areas. Threats Today s Kishwaukee River basin is much changed from the presettlemcnt era. Forests, wetlands and prairies have given way to agriculture, artificial water drainage, and urbanization.Today's landscape is 85% agricultural and urban. Basin acreage - 779,744 Total natural areas - 3,379. 1 acres High-c|ualitA' natural areas - 52 acres Nature preser\'es - 247.4 acres Flooding - One of the greatest concerns for area residents is flooding. Average annual flow in the basin has jumped more than 50% since 1970. Although average precipitation has increased, other explanations for the increa.sed flow include the drainage and removal of wetland areas and the dis- charge of treated waste water into the river basin. Erosion - Field drainage has played an impor- tant role in increasing the volume and rate of runoff from cultivated fields. With the majorit)' of the soils in the watershed having loess as their uppermost parent material, the potential for soil erosion is moderate to high and the increased discharge is causing erosion problems along the Kishwaukee River and its drainage. Channel widening and bank failures are two major erosion problems. Habitat loss -The loss of natural habitat in the basin has been .severe. Prior to European settlement in 1820, the area was a montage of different forest i\pes, savannas, hiacksoil and gnivel prairies, and a variety of wetlands from marshes to fens. For exam- ple, wetlands covered as much as 31% of .Mcllenry County. 21%i of Boone, and 14% of Winnebago. Today, McHenr)' County siill has the highest jut- centage of wetlands — 6%. Overall, only 2.6% of the area's land is wetland. 'lliere has also been a similar decline In prairie, savanna and lorcsi. Aliogciher only 52 acres (0.(M)6%i of total area) remain in a high quality, undegnided condition, all of it wetland and prairie. No pristine forest or savanna remains. At least 2 G2 of the 2Vi) bird species that regularly occur in the state can be found in the area. 46 Critical Trends in Illinois Ecosystems Maintaining even small, temporary wetlands would benefit almost all of the reptiles and amphibians in the area. This is even more severe than statewide levels, where only 0.07% of the total area remains in a high quality undegraded condition. Opportunities To address area flooding and habitat loss, a critical element is to protect and restore wetlands. Wetlands mitigate the effects of storm flow in streams by retaining excess rainwater and delaying delivery of water to the main stream. Reduced stream flow will not only reduce flooding and ero- sion, but will also enhance the quality of the stream by limiting channeling and bank failure. Maintaining even small, temporary wetlands would benefit almost all of the reptiles and amphibians in the area; the American toad, western chorus frog, and bullfrog do well in small patches of cattail marsh, even when the marsh is completely surrounded by developed land. Additionally, wet- lands are important stopover sites for migrating birds and are heavUy used by nesting birds. Remnants of other ecosystems can play a key role in preserving the ecology of the area; small pieces of natural communities can still harbor diversity. For example, an unknown quantit)' of degraded prairie most likely remains, particularly along railroad rights-of-way. Some of this degraded prairie has high restoration potential. Sugar-Pecatonica Rivers Basin The Sugar-Pecatonica Rivers basin encompasses approxi- mately "^96.2 square miles in north central Illinois. The Pecatonica is the dominant stream, accounting for two- thirds of the drainage area. It originates in Iowa County, Wisconsin, crosses the Illinois border near the town of Winslow. flows south to Freeport, then heads east-by northeast towards its confluence with the Rock River near Rockton. In Illinois the length of the Pecatonica River is 92.4 miles. Basin acreage - 509,679 acres State land* -701 acres Count)' land - 3,334 acres Total natural areas - 3,647 acres High-quality natural areas - 85. 7 acres Nature preserves - 672 acres * Does not include natural areas or nature preserves that may be state owned. Much of the land in the basin is used for agriculture — 53% in cropland and 36"o in grassland, most of which is non-native forage grasses such as hayfields and pastures. Only 8% of the area is forest or wetland. The area has a number of natural commimitA- remnants that are otherwise rare or absent in the rest of Illinois, especially prairie, wetland, and sand communities. The Sugar and Pecatonica river corridors have some of the most cxtensi\e riparian wetland communities left in nordiem Illinois. The sand area between the Sugar and Raccoon Creek supports several rare sand communities, and the eastern portion supports some of the best examples of dok)mite prairie left in die state. Otlier significant features; • high qualirv' natural areas include 60 acres of upland forest, almost eight acres of prairie, si.x acres of shrub swamp, eight acres of sedge meadow, and three acres of pond; Rock River Watershed 47 the Winnebago County Forest Preserve District is acquiring many other native habitats, includ- ing several high qualir\' wetland sites and a number of prairie and wetland restoration projects; the Biological Stream Characterization rated much of the Sugar River as a Class "A" stream (unique aquatic resource) and rated the Pecatonica and several of its tributaries as a Class "C" stream (moderate aquatic resource); two segments of area streams, for a total of 1 0. 1 miles, are recognized as Biologicall)- Significant because they support a high level of mussel and fish diversity; 15,144 acres have been designated a Resource Rich Area. defg ■ A Cropland (53.5%) W B Grassland (35.9%) ■ C Upland forest (4.7%) ■ D Urban/built-up (2.4%) ■ E Bottomland forest (1.8%) D F Non-forested wetlands (1.2%) D G Water (0.5%) Figure 33- Siigar-Peccitonicci rivers basin land cover Plant and animal life Thirt)'-three percent (850) of the state's native plant species occur in the area. Of these, 26 are state endangered (the eastern prairie fringed orchid is also federally threatened) and six are state threat- ened. Most of these rare species occur in the prairie and wetland communities, particularly the sand communities in the Sugar River drainage and the wetland habitats associated with the bog area in the Raccoon Creek drainage. At least 261 of the 299 bird species that regu- larly occur in the state can be found here. Because of the geographical position of the area and the rather diverse array of habitats, several species of birds either reach or are near the northern (e.g.. yellow-throated warbler, white' of activities. Threats Agriculture and urbanization ha\e changed the mosaic of forests, wetlands, savannas, and prairies that existed before European settlement. A few of the resulting ecological threats: Habitat loss - Ver)' few natural communities remain in the area. For example, in 1820 wetlands covered as much as 6% of Ste|^henson Cx)unt\ and 1 i'% of Winnebago Clounty. Onl> 2.9".. of the area remains in wetland today. Furthermore, only 0.01% of the total area remains as high-qualit>' habitat, which is even more severe than the statewide level of 0.07%.. Habitat fragmentation ■ Ihe lack of habitat leads to several other common ecological problems, particularly habitat fragmentation. Habitat fragnientation interrupts biological The state threatened river otter IMS been observed here, and five T&E species of fish are found here. 48 Critical Trends in Illinois Ecosystems Only 12.4% of the Pecatonica River was rated as "full support "and the remainder was rated as "Partial Support/Minor Impairment". interactions, ecological processes, and species migrations, and reduces habitat heterogeneity. The outcome typically is loss of species diversity. Exotic species - Degraded natural communities are particularly vulnerable to being invaded by exotic species, which can overnm native plant communities and reduce biodiversity. Garlic mustard and reed canary grass are two exotic species known in the area; many of the remaining marshes and sedge meadows are threatened by these non-native species. Impaired water quality - Only 12.4% of the Pecatonica River was rated as "full support" (water quality meets the needs of all designated uses pro- tected by applicable water quality standards), and the remainder was rated as "Partial Support/Minor Impairment" (water quality has been impaired to a minor degree). Major water qualit)' problems include municipal wastewater discharges, and phos- phorous and siltation from agricultural runoff However, of the 40 tributaries to the Pecatonica, 34 were rated as "full support" along their entire length. Opportunities A large amoimt of wetland habitat in the area could be restored. Tliis is especially true alotig the major stream atid river corridors where restoring natural riparian vegetation and connecting existing wet- land communities would increase habitat, as well as provide additional wetland functions — store floodwater and reduce siltation and nutrient load- ing. Reducing silt atid chemical runoff will improve the water quality of the streams, thereby enliancing their ability to support fish, as well as minks and river otters. Restoring riparian zones will renew their ability to act as dispersal corridors tor man}' animals, such as the gray fox atid bobcat, thus reducing the effects of habitat fragmentation. The continued acquisition of larger qualir>' wet- lands that remain in the area would allow the bird population to become more successful and self-sus- taining, and provide large home ranges necessar)' to support bobcats and river otters. However, main- taining even small, temporar)' wetlands would benefit many animals, especially reptiles and amphibians. More infortnation is needed on habitat remnants, particularly abt)ut the distribution, abundance, qualitative condition, and ecological trentis among remnants. Prairie restoration, coupled with the preserva- tion of native prairie and other grassland habitats, would provide additional habitat for animals such as badger and red fox. and provide \aluable sites for reintroducing Franklins ground squirrel. Larger grassland areas of at least 100 acres would benefit grassland birds most sensitive to grassland fragmen- tation. Exotic plant invasion can be addressed by restoring habitat with native plants, conducting controlled burns, treating them directly or using biological controls. Driftless Area The Driftless Area encom- passes approximately 996 square miles in extreme northwestern Illinois. Bordered by Wisconsin to the north and the Mississippi River to the west, the area includes nearly all of Jo Daviess County, most of western and northern Carroll Coimt)\ the northwest- em comer of Wliiteside County, and small segments of western Stephenson Count). The Driftless area is so n;mied because it has little or no "drift" — the sediments deposited across the remainder of northern and central Illinois by glaciers that bypassed this corner of the state. The rough, unglaciated terrain features wooded uplands, rolUng hills, narrow \alleys. numerous streams, springs, and even cliffs and bluffs. Basin acreage - 637, 115 acres State land* - 4,880 acres area Federal land - 40,929 acres Total natural areas - 33.31 1 acres High-qualin natural areas - 48. 3 acres Nature p^eser^ cs - "'23 acres * Does not iiicliiite mittinil iiix'iis or luitiin' preserivs thill may Ih> state otviied. Agriculture is the dominant land use with crop- lands and grasslands (which are mostly pasture) combining for almost three-fourths of the hmd. Farm lands in this area are not as concentrated in row cr<^ps. which account for only 32% of agricultural land compared to "0".. statewide. Tliis is partly due to the difficulty of cultivating some of Rock River Watershed 49 the area's more nigged terrain. Forests account for one-fifth of the area's land cover, well above tlic statewide average of 11.3%. Most of the forested areas are found on the slopes along rivers and streams. Key features include: • 70 miles of streams iiave been designated Biologically Significant because of their fisii and mussel diversit)-, • 30 acres of dry sand pmirie and four acres of dry-mesic sand prairie are designated as liigh-qualir\' ecological communities, account- ing for 7. "5% and 4.2% of the state acreage, respectivel), • diverse cliff communities provide an array of unique habitats, depending on orientation to sun and wind: the most unusual are a handful of algific slopes which retain subsurface ice through most of the year and harbor northern and relict species, • 191,814 acres have been designated a state Resource Rich Area. EFG ■ A Grassland (40.5%) D B Cropland (33.2%) D C Upland forest (17.8%) ■ D Water (4.5%) ■ E Bottomland forest (2.2%) D F Urban/built-up (1.3%) D 6 Non-forested wetlands (0.5%) Figure 34. Driftless Area land cover Plant and animal life The area supports communities that are nire or nonexistent elsewhere in the state, notahl}' sand prairies and cliff communities. Habitat is particularly good for birds. Of the approximately 271 species found here, 138 breed or formerly bred here, and 18 — 43% of the state total — are listed as state threatened or endangered. Other threat- ened or endangered species include the river otter and timber rattlesnake. Approximately 42% (915 species) of Illinois' native flora occurs here, an area that comprises only 1.7% of the states total la.id area. I ill) -live plants are state-endangered and 1 1 are state-threat- ened. Of these, 17 species are found in Illinois onl\ within the Driftless Area, mostly on algific (cold-pro- ducing) slopes, sand prairies, and dolomite cliffs. Local economy and outdoor recreation In 1990, the population of (Carrol and Jo Daviess counties, the two main counties in the area, stood at 38,600, 10% below that of 120 years ago. The area is rural, with only one-tjuarter of the population living in urban areas. In 1994 the area economy supported nearly 21,000 jobs and generated $541 million in personal income. The services sector almost doubled in size, growing from 11% of employment in 1970 to its present share of 23%. Unlike many other parts of the state, manufacturing employment also grew, by about 1.5% annually. Althougli farming employment has declined it continues to be an important part of the local economy, with 10-12% of wcjrkers employed on area farms. Outdoor recreation opportunities are largel)' shaped by the area's rough terrain and its major streams, especialh' the Mississippi River. The river, its fioodplain. and diverse habitats attract a varierv' of wildlife ami provide ample opportunities for boating, hunting, and fishing. Two major state parks. Mississippi Palisades and Apple River c;any()n, collectively attract HiO, ()()() visitors annually, generating $8.6 million in economic out- put anti 130 jobs. The Upper Mississippi National Wildlife and I'ish Refuge also stretches along the riser, providing habitat lor fish and waterfowl. Much of the 14,000-acre Savanna Army Depot will eventually be tran.sferred to the refuge. Threats While the Driftless Area's topographical complexity and array of habitats are unique, its ecological ilireats are familiar: enision, water contamination. Although fanning employment has declined it continues to be an important part of the local ecrmomy. 50 Critical Trends in Illinois Ecosystems While the Driftless Area is blessed with a variety of habitats, they are often separated by agricultural or developed land. and fragmentation and degradation of habitat. Erosion - Soils here are relatively thin, and steep slopes promote soil erosion and sedimentation in streams and rivers. One study found that more than half of Jo Daviess County has a slope of more than 7%, and nearly one-third exceeds 18%. Careless management in the 1930s led to the creation of large gullies, with associated problems of soil loss, flooding, and sedimentation. Since then, farmers have increasingly used conservation tillage, vegetation has been planted on some of the more sensitive slopes, and gullies have been repaired by installing retaining structures and by adding fill. Some evidence suggests that improved land management practices have helped to reduce flooding as well as soil loss. J Hp m:^ H H *>-' *■ .1.^,'^ ^^'' ^"^ Water qualit>- - Sections of the Apple and Mississippi rivers, and most of the Galena River, were rated by the Illinois Water Quality Report as "Full Support," indicating that water quality meets the needs of all designated uses. The Plum River and Carroll Oeek were downgraded slightly for phosphorous contamination from municipal waste- water discharges. There is some concern that large-scale live- stock operations may threaten groundwater and surface water in the area. Two hog facilities with 4,000 animals each are located near the headwaters of the Apple River and neighbors and health officials are concerned about the potential impact of large volumes of animal waste. lA)cal geology adds to the concern — most of the area lacks the thick layer of glacially deposited till that filters out most contaminants. Nearly 60% of the area is highly or excessively vulnerable to aquifer contam- ination, and another 8% is moderately vulnerable. Habitat degradation and fragmentation - Almost all of the original prairie has been destroyed and many of the areas wetlands have been drained for agriculture or flooded for navigation. Fire suppres- sion has fostered maple invasion of oak forests, and subdivisions are carving up ecossstems to provide homes for people drawn, in part, by the areas scenic beauty. Opportunities Vast potential exists for prairie restoration, especially sand prairies and various hiU prairies. The few remaining large expanses of prairie, including the sand prairies at the Savanna Army Depot, should be protected — fragmented plots tend to support only small populations of species that are vulnerable to local extinction. Actively managing prairies, including prescribed burning, will Unlit encroachment by invasive species such as wood)' plants. Reestablishing native vegetation along river corridors could bring significant benefits. Siltation. desiccation, and higher than normal temperatures would all be reduced to acceptable levels if streams were lined with native plants that shaded the stream, stabilized the banks, and filtered sediment and chemicals from runoff before they reached the stream. Measures to impro\'e the integrirv' of rivers and their banks would do more than impro\e habitat for aquatic wildlife; the\' can also serve to improve the corridors between diverse habitat, mitigating the threat of fragmentation. Wliile the Driftless Area is blessed with a \arict> of habitats. the\ are often separated by agricultural or developed land. This is problematic for species such as amphibians. \\ hich often travel long distances between breeding and non-breeding habitat. Two of the area's most notable species, the timber rattlesnake and the bt)bcat, also demand a variety' of habitats for foraging, breeding, and resting. Fox and Dcs Plaincs Rivers Watershed 51 CHAPTER FIVE Fox and Des Plaines Rivers Watershed Located in the northeastern part of the state, the Fox and Des Plaines is the most urbanized ISIS watershed. More than one-third of the area consists of urbanized and developed land, accounting for one-half of such land cover in the state. The watershed has the most non- forested wetland acres in the state as well as the highest per- centage of wetland in a water- shed. It also has the least amount of cropland acreage and the smallest per- centage of cropland in a watershed. (See page 104 for a color map of the watersheds land cover ) Five Resource Rich Areas are in the Fox and Des Plaines watershed — Thorn Creek, Des Plaines River, DuPage River, Chain O Lakes-Fox River, Illinois Beach and Prairie Parklands. • Thorn Creek is a relatively small area — .^2 square miles in a heavily urbanized area. Natural resources are confined along streams and in forest preserves. The Thorn Creek Nature Preserve has narrow ridges and deep ravines, shallow depressions, broad uplands and the stream valley. • Tlie Des Plaines Ri\er RRA is a small — 68 square miles — highh urbanized site which forms a narrow corridor along the river from just west of Chicago to Joliet. Relatively high percentages of upland woods and non-tbrcsted wetlands occur at this site. Important natural features include prairie, savanna, river bluffs, cliffs, wetland, floodplain and upland forest. • The DuPage River RRA, com- prised of the watershed of the East Branch of the Du Page River, is located in the highh' urbanized western sub- urbs of Chicago. With its small size (81 square miles) it has a high percentage of upland forest (19%) and non-forested wet- lands (3%). The Chain O'Lakcs-Fox River RR/K (44"^ square miles) encompasses the area of most recent glaciation in Illinois. Significant natural features include glacial landforms, natural lakes, and Table 18. Watershed Land Comr Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest 290,149 1 1 .3% (4) 7.0% (7) Gra,ssland 326,288 12.7% (8) 5.1% (10) Non-forested wetlands 78,237 3.1% (1) 22.0% (1) Bottomland forest 26,448 1.0% (9) 3.0% (10) Water 36,275 1.4% (5) 7.3% (7) llrban/liuilt-up 931,664 36.3% (1) 49.8% (1) Cropland 877,925 34.2% (10) 4.1% (10) Total acreage 2.566,987 100.0% 7.1% (9) The watershed has the most non-forested wetland acres in the state as well as the hiji}}est percenta{>e of wetland in a watershed. * The watershed's percentafie of the land coi'er t}'/)e statewide, e.g., 7% of the states upland forests are located in this watershed. Note: the watershed's rank (IstlOth) is shoiiii in /xnvntheses. 52 Critical Trends in Illinois Ecosystems Most fish richness measures were also close to statewide averages and habitat quality was slightly higher than the statewide average. many types of wetland — bogs, fens, seeps, and shallow and deep marshes. Some rare species and community types are limited in their distribution to this area of the state. Urban expansion from the Chicago metropolitan region continues to put severe pressure on the natural resources here. Even though its boundaries include urbanized areas of the Chicago metropolitan region, the Illinois Beach RRA (77 square miles) is one of the most ecologically rich and unique areas in Illinois. Its location on the shores of Lake Michigan provides a diversity of habitats that support a wide variety of plants and animals. Significant and unusual topographic features include beaches, ridges and swales, and dunes. The area is an important migratory route for birds. The dominant feature of the Prairie Parklands RRA is the recently created Midewin National Tallgrass Prairie, the nation's first federally designated tallgrass prairie, at the former Joliet Arsenal. Significant natural resources include prairies, wetlands and streams. The largest concentration of upland sandpipers in the state is in the Prairie Parklands area. The RRA takes in 239 square miles — 41% in this watershed and 59% in the KankakeeAtrmilion/Mackinaw watershed. ECOSYSTEM MONTTORING HBI values at the eight sites sampled by CTAP biol- ogists indicate moderate organic enrichment, while EPT richness was slightly below the statewide average. Most fish richness measures were also close to statewide averages and habitat qualit^■ was slightly higher than the statewide average. One high quality stream was Person Creek below Kane Count)'s Lero\' Oaks Forest Preser\-e; it had high habitat quality, good EPT and HBI scores, and high fish richness. The lowest quality' site was Willow Creek at Rosemont. It supported no EPT species, relatively low fish richness, and had a ver>" lo-w habitat quaUt)' score. RiverWatch volunteers collected 313 samples at 139 sites on 91 streams. Most RiverWatch biological indicator data also suggest the watershed is below-average in ecological qualin-. It ranked sev- enth and eighth among the ten watersheds in MBI and EPT taxa, suggesting that organic pollution has disturbed sensitive taxa. It ranked fifth in taxa richness — with 9. 1 taxa per site, slightly above the state average of 8.9 — but seventh in taxa dominance. Sowbugs and h^dropsycliid caddisfh* are the most common taxa. a CTAP -INHS River Sites RiverWatch Sites A ForestWatch Sites Figure 35. Monitoring sites Table 19. Wati rshed Indicator Scorecard Indicator Watershed Value Statewide Value Watershed Ranking Macroinrertebrates HIM 5.1 5.2 5 MBI 6.0 5.7 7 EPT richness 6.6 7.1 6 EPT t;ixa (RW) 2.2 2.6 8 Taxa richness 9.1 8.9 5 Taxa dominance 80.4% 80.4% 7 Fish Native fish 14.3 13.6 4 Darter richness 1.8 1.9 5 E.\otic species 0.3 0.2 6 Habitat Habitat score 94.9 88.6 4 Fox and Des Plaines Rivers Watershed 53 Table 20. MBI Values Table 21. Tree Species with the Hifihest Importance Values Statistic 1995 1996 199^ 199« 1999 Overall Mean 6.65 S.91 6 11 S 95 5 81 6.02 Standard deviation 1,^8 0.92 9H 1.02 0.97 1.02 Minimum 4.23 im ^ 52 .-i 6.3 3.47 3.47 .Maximum 9.44 9.9" 9.50 11.00 8.«0 11.00 Number of sites* 10 40 63 110 83 306 * Only samples with cit least 25 organisms were included in the tDialysis ForestWatch volunteers monitored 14 sites in the Fox and Des Plaines Rivers watershed in the fall of 1998. Ten were upland forests (4 oak-hickoiy, 4 maple-ash-basswood, 2 bur oak) and four were bottomland forests (2 ash-elm-maple, 1 ash-cotton- wood, 1 scrub). Tree species richness ranged from four to 16 species per site, averaging 10.2 per site, slightl)' below the statewide average of 11 .8 species per site.Tlie site with only tour species was domi- nated b>' hawthorn trees and was characterized as scrub. Thirty-eight tree taxa were recorded in the watershed (75 taxa statewide). Tlie great abundance of buckthorn recorded here is alarming. This non-native invasive woody plant is particularly abundant in northeastern Illinois and seems to be a problem throughout the watershed. It grows in both shrub and tree form, spreads rapidh- and crowds out native vegetation, reducing the diversity' of the forest and the ability of native plants and animals to survive. In general, the trees that were most abundant also had the highest basal areas and importance values (Table 2 1 ). Buckthorn is an exception. Since it is an understory tree it does not grow very large and is only ninth in ba.sal area and seventh in impor- tance value. In contrast, white oak trees grow very large. Despite being seventh in abundance, they have the greatest basal area and are third in importance. Two upland sites showed some signs of maple takeover. The site graphed in Figure .-^6 shows that sugar maples dominate the smallest size class, indicating poor regeneration by oaks and hickories and the po.s.sible future dominance of maples. This likely reflects changes in the fire regime in the area. Importance Value Species % of total trees counted (n= 1,943) % of total basal area (22.1m-/lia) 30.6 Ash 14% 16% 22.9 Basswood 11% 11% 20.7 White oak 6% 19% 15.5 Hawthorn 9% 3% 15.4 Bur oak 3% 11% 13.7 Slippery elm 7% 5% 13.5 Buckthorn 14% 3% 9.0 Black cherry 6% 3% 7.2 Sugar maple 3% 4% 6.7 Red oak group 3% 4% There were no signs of gypsy moths or dog- wood anthracno.se at any site.Anthracnose has not been a problem in northern Illinois but gypsy moths have been entering northeastern Illinois, primarily from Wisconsin, and pose a major threat to forest health. I 10-20 Tree diameler. centimeters ■ Oaks ■ Hickories Q Maples Figure 36. Maple take-over in an oak-hickory forest Abundance of invasive shrubs (primarily non- native) was rather high, comprising 74% of the 1,340 total shrub stems recorded. Honeysuckle shrubs, buckthorn, and European highbush cranberry reached high densities here comjiared to the statewide average (I'ig. 37). Ninety-eight per- cent of the buckthorn, 60% of the honeysuckle shrubs, 22% of the multiflora rose, and 1 00% of the cranberry recorded across the state were recorded in this watershed. Buckthorns were found on nine of I I sites. Two sites were particularly dominated b\ buckthorn ami contributed most of the 54 Critical Trends in Illinois Ecosystems Spring monitoring also recorded numerous non- natives among the ground cover buckthorn stems for the watershed and for the state. These numbers are not surprising since this is one of the most populated areas in the state and a major port-of-entry, both of which increase the odds that non-native plants will be introduced. Spring monitoring also recorded numerous Non-lnvaslve vines Non-invasive !T- ^ ^^^^^^^^^^^^H . J Japanese honeysucl' land - 17,270 Total natural areas - 16,125 acres High-iiireitehmtes HBI 5.2 5.2 6 MBI 5.4 5.- 3 EPT lichncss 5.0 7.1 9 EP r t;L\a (RW) 3.4 2.6 2 T;ixa richness 9.2 8.9 4 Taxa dominance 78.4% 80.4% 3 FL<:I.) Native fish 14.0 13.6 5 Darter richness 2.1 1.9 4 Exotic species 0..^ 0.2 6 Habitat Haliitat score ■'-.1 88.6 9 Kankakee, Vermilion and Mackinaw Rivers Watershed 61 Table 24. MBl Values Statistic 1995 1996 1997 1998 1999 Overall Average Standard dc\ iation Miiiinium Maxiimini Number of sites' 6.20 5.46 =>M 5.85 4.98 5.43 1.81) 0.^6 0.96 1 .•(() 1.25 1.2.-^ 4.-'l 3.~9 4(11 1..39 2.03 2.03 10."'' 6.49 -.02 -.95 ^.-4 10.7- 9 1- 10 7 20 63 * OiUv siimples with at least J5 organisms were included in the iintilysis. ForestWatch volunteers monitored two sites in the fall of 1998, an oak-hickory upland forest and an ash-elm-maple bottomland forest. Species richness was 12 species at one site and 15 at the other. The average of 13.5 species for these two sites is above the statewide average of 11.8 species per site. A total of 21 tree taxa were recorded. In general, the trees that were most abundant also had the highest basal areas and importance values (Table 25). The exception is oak trees which were fewer in number but had a larger basal area than most species. Table 25. Tree Species with the Highest Importance Values Importance Value Species % of total trees counted (n=156) % of total basal area (19.8m^/ha) 63.7 White oak 6% 47% 30.9 Hawthorn 31% 7% 19.9 American elm 19% 7% 17.0 Swamp white oak 3% 17% 11.9 Ash 8% 2% 11.0 Hackbcrr> 8% 3% 6.2 Shingle oak 4% 2% 6.2 Swamp chestnut oak* 2% 5% 5.3 Black locust 2% 1% 4.9 Honey locust 3% 4% lieamse sucini/) chestnut oak is Jhtiiiil iiuiiiily in smilhcrn Illinois, this was likely misidenlified and slmuld Iw cilher white oak or swam/) white oak. Neither of the two sites showed signs of maple takeover, gypsy moths or dogwood antiiracnosc However, more sites need to be monitored to determine if these threats are present in the water- shed. Of the 420 shrub and vine stems recorded, 89% belonged to two invasive shrub species — the native Missouri gooseberry and the non-native multiflora rose, which was especially abundant. These two sites contributed nearly 50% of the total multiflora rose recorded across the state. '^^M: ..•$1-'* ^^H Spring monitoring at one site recorded two disturbance-sensitive species — white trillium and large-flowered bellwort — and one non-native invasive species — ground ivy. None of these three plants were widespread within the site. Non-invasive vines Non-invasive shrubs Gooseberry Multiflora rose Honeysuckle Bucktiiom ■ St! ■ Ka rtewic nkak "el ee| — 1 ■ > 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Stems per hectare Figure 41. Number of invasive and non-invasive shrub and vine stems REGIONAL ASSESSMENTS Tivo regional assessments have been conducted ill this uatershed —for the Kankakee River ralk'v and the .Mackinau- River basin. Tl.u'se two sites contributed nearly 50% of the total multiflora rose recorded across the state. 62 Critical Trends in Illinois Ecosystems '^t^^-^ ^^^^ In general, relative losses of presettlement habitat in the Kankakee exceed statewide averages. Kankakee River Valley The Kankakee River valley takes in 2,169 square miles, including nearly all of Kankakee and Iroquois counties plus parts of four adjacent counties in north- east Illinois. Two "mainstem" rivers dominate — the Kankakee, which flows west across the valley until it joins the Des Plaines to form the Illinois River, and the Kankakee's principal tributary, the Iroquois. More than three-fourths of the land area is cropland and nearly 16% is grassland — pastures and haj'fields, idle fields, remnant prairies, and grassy strips along roads and railroad tracks. Forest covers 3-1% of the land and non-forested wetlands cover another 0.5%. Forests and wetlands, along with the open water of the river systems, are the refuges where much of the region's plant and animal life persists. CDEFG ■ A Cropland (77.6%) ■ B Grassland (15.8%) D C Urban/built-up (2.5%) ■ D Upland forest (2.3%) n E Bottomland forest (0.8%) ■ F Water (0.5%) ■ G Non-forested wetlands (0.5%) Figure 42. Kankakee River valley land cover In general, relative losses of presettlement habitat in the Kankakee exceed statewide averages. And except for forest and savanna, the ecological qualit)' of what does survive is lower in the Kankakee valley than in the rest of the state. More than 90% of the valley was prairie (including savannas) when Euro-American travelers first saw it. Today about 56 acres of prairie survive in the region, or 0.005% of the original. Conservative calculations suggest that the presettlement Kankakee valley included 375,000 acres of wetlands of various types. An estimated 96% of them are gone. Only about 236 acres of the remaining wetlands (not counting forests along streams) persist in their presettlement state, and of these, only six acres remain «'.< not iiuiiulc luitiinil iiiviis or luitiirv presents tbiit niiiy he sttitc ouiietl. The area is home to at least 249 of the estimated 299 bird sjiccies that regularly occur in Illinois.Ofthe.se. 1h3 arc know n to breed or used to breed in the area and 19 of these are listed as threatened or endangered in Illinois. Kankakee, Vermilion and Mackinaw Rivers Watershed 63 Six species of fish known from the region are listed by state authorities as being endangered or threatened. One of them, the weed shiner, is among the rarest fishes in Illinois and the only large population of the species is found in the Kankakee valle>'. Smaller populations are known in onl}- two other localities in the state. Of the more than 1 .000 species of native plants known in the area, 75 are species whose survival in Illinois is considered uncertain, and two — Mead's milkweed and the eastern prairie fringed orchid — are rare in the nation as a whole. Local economy and outdoor recreation Over the past century the combined pop Illations of Kankakee and Iroquois coun- ties more than doubled, with most of the growth occurring in Kankakee Count)'. Kankakee County is highly urbanized, with almost seven out of ten people living in urban areas. Iroquois County is more rural with fewer than one out of five residents living in urban areas. During the past decade the area has lost population as it has lost some of its indus- trial base. Manufacturing employment fell 32% in the last 25 years, while service sector employment rose 1 20%. Manufacturing is still the largest source of earnings in Kankakee (bounty, however, reflecting its higher wages. Services and trade provide the most jobs. In predominantly rural Iroquois (bounty farming is the third largest employment sector, alter services and trade. Outdoor recreation opportunities in the Kankakee River valley are shaped largely by the river it.self Kankakee River State Park is visited by approximately 1.2 million people annually who come to hike, camp, hunt, fish, ride horses, watch wildlife, and go boating. The smaller Iroc|Uois C^ounty Con.servation Area is known for its sand dune and prairie marsh habitats and its excellent pheasant hunting. Visitors to these sites generate about $14 million in output and 220 jobs for the local econom)'. Threats Habitat loss and fragmentation - Construction of roads, fields, and houses divides once-intact forests, wetlands, or prairies into small habitat "islands." Tlie entire local populations of some plant and animal species in these splintered tracts may include onl)' a few individuals. Tlie smaller such local popula- tions are, the more vulnerable they usually are to disease and in-breeding stress. Fragmented habitats also are often too small for species that need far- flung home ranges. For example, gray squirrels are rare or absent in the area because the extensive tracts of forest they need are rare here. The minimum forested acreage thought necessary to shelter popu- lations of breeding songbirds is 500 acres. None of the three largest tracts of .savanna — found upstream of Momence on the Kankakee and along Spring Creek between Oilman and Crescent (lit)' — is bigger than 428 acres. Grassland and wetland birds al.so lack sufficient breeding space within the Kankakee valley. Fortunately, planned restoration of large tracts just t)utside the region — at the Midewin National Tall Grass Prairie near Joliet and the (irand Kankakee Marsh across the state line in Indiana — sliould help replenish those populations locally. Fragmentation also severs the natural land- .scape links that connect disparate habitats. Fach spring, amphibians like the American toad migrate to lowland areas from upland forests lo breed, while reptiles move to upland retreats to hibernate each fall; fragmentation blocks these natural movements. Grasshind ciiul wetUnid birds also lack sufficient breeding space within the Kankakee ralley. 64 Critical Trends in Illinois Ecosystems Prairie remnants in restorable condition may persist along railroad rights-of-way. Stream alternation - The most direct way to disturb ecosystems is to modify the way they work. Construction of artificial drainage systems is Capart from the plowing of the prairie) the most wide- spread form of ecosystem modification in the Kankakee vaUey. Absence of fire - Oak-hickory forests are not reproducing themselves because the understories are not allowed to burn, resulting in forest floors too shady for sun-loving oak seedlings to flourish. Shade-tolerant maples thrive, however. This has implications for wildlife; squirrels and chipmunks tend to be most abundant in forests heavy with nut-producing trees like oaks and hickories. Opportunities Sensible restoration could enhance and expand three large islands of habitat types that have become scarce in most of the rest of Illinois — the upland forests of the Kankakee River State Park, the forested wetlands of the Momence Wetlands and the savannas and grasslands of the Iroquois Count)' Conservation Area. (Extensive savannas also persist on private lands in the Kankakee Sands area.) This would again make the Kankakee host to large breeding populations of birds of the savanna, forested wetland, and emergent wetland. Other opportunities exist to enhance ecosystems. • Stream corridors, even drainage ditches, can serve as dispersal corridors for plants and animals. Restored riparian zones, for example, enable amphibian and reptiles like the American toad to move safely from the uplands of the Kankakee where it spends most of its life to lowlands where it breeds. Hedgerows in fields offer similar connecting havens for mammals. • Prairie remnants in restorable condition may persist along railroad rights-of-way; these have been cataloged by local conservation groups such as the Crrand Prairie Friends. • Shrubs planted alongside drainage ditches provide shelter for birds, shade water for fishes, and hold ditch banks against erosion. Mackinaw River Basin The Mackinaw River origi- nates in Ford Count\- near Sibley and winds approxi- mately 130 miles in a westerly direction before joining the Illinois River near Pekin. The basin encompasses 1.138 square miles in central Illinois and covers parts of sbc counties. Principal tributaries are Panther, Walnut and Money creeks. The ri\er basin bisects a highly productive agricultural landscape and is bounded by two metropolitan areas. Bloomington- Normal on the southeast and Peoria on the northwest. More than three-fourths of the land is in cropland; corn and soybeans are the predominant crop with )'ields above the state a^"erage. McLean County contains more farmland — nearly "00.000 acres — and produces more com and soybeans than am' other counts- in the state. Habitat loss rates in the ba.sin seem to exceed rates for the state as a whole. Prairie accounted for almost three-fourths of the presettlement land- scape; today the onl\- representative of the prairie ecosystem is 1.5 acres of high quality hill prairie. Wetlands have largely disappeared and occup\- only 0.3"" of the basin. Forest has declined to S",. of the land area, but much of the riparian zone throughout the basin retains at least a narrow forested strip. This buffer stabilizes the river banks and is consid- ered a primary reason for the relati\ eh good health of the Mackinaw River. Other significant features: • natural communities represented in higli quality natural areas include glacial drift hill Kankakee, Vermilion and Mackinaw Rivers Watershed 65 prairie, loess hill prairie, dr>'-mesic barrens, mesic upland forest, and wet floodplain forest; the Mackinaw is considered one of the finest examples of a prairie stream left in Illinois and 136.4 miles have been designated as Biologically Significant; Panther Creek and the portion of the Mackinaw River north and east of the Mackinaw River Fish and Wildlife Area are both designated as "Class A" streams, indicating that they are high-quality habitats for a rich variety of plants and animals; 125,008 acres have been designated a state Resource Rich Area. P dEfg ■ A Cropland (76.9%) ^ ■ B Grassland (13.5%) 'M } IS C Upland forest (4.9%) ■ D Urban/built-up (2.3%) D E Water (1.32%) n F Bottomland forest (0.8%) D G Non-forested ^^^ ^A wetlands (0.3%) Figure 43- Mackinaw River basin land cover Plant and animal life The Mackinaw is the only central Illinois site for a unique, stream-dwelling plant, the state-endangered heart-leaved plantain. Here you can also find the black-winged damselfly and the ruby-spot dam- selfly — both are indicators of good water quality. The macroinvertebrates found in a recent survey appear to be more diverse than those of many other watersheds in Illinois, another indication of good water quality. Basin acreage - 728,495 acres State land* - 1 ,248 acres Total natural areas - 3,182.6 acres High qualit)' natural areas - 43 acres Nature preserves - 84.3 acres * Does tiol incliidf luiliinil tiretis or nature preserves that may he stale owned. While only 9% of the plant species found in Illinois can be found in the Mackinaw basin, almost three-fourths of the mammals occurring in the state live here. At least seven state T&E species occur in the basin: the Illinois chorus frog, western hognose snake and Illinois mud turtle (all limited to the sand areas in the southwest corner of the basin), the short-eared owl and loggerhead shrike, as well as the heart-leaved plantain and tall sunflower. Local economy and outdoor recreation The three main counties through which the Mackinaw flows — McLean,Tazewell and Woodford — have all grown in population by 60-70% since the late 1940s. In the past decade, however, Woodford and Tazewell counties have lost popula- tion as manufacturing jobs declined in the Peoria Metropolitan Statistical Area. McLean County has continued to grow with an economy built around insurance, higher education, and, most recently, automobile manufacturing. While farming may be ubiquitous in the Mackinaw River area, agriculture produces only 2% of the area's income and this percentage has declined over time. The area does not have any high profile outdoor recreation areas, but the streams and surrounding areas offer an array of outdoor activi- ties, from fishing and hunting to canoeing. Threats Pollution - Water pollution from built-up and agri- cultural lands has led to a decline in the aquatic life of the Mackinaw since the 1950s, particularly the mussels and fishes of the lower drainage. Clean water mussels such as the slippershell and spike have been replaced by species that are tolerant of lower water quality, such as the white heelsplitter and three ridge. Sedimentation - Compared to the other major tributaries of the Illinois River, the Mackinaw River basin has one of the highest sediment )'ield rates in the Illinois River basin. Excess sediment comes from increased erosion due lo urlian atid agricultural land use patterns. In urban landscapes the velocity of runoff during storms increases, causing high levels of soil erosion. In agricultural landscapes on flat uplands, most streams have been ditched and the fields tiled to promote drainage, causing water to speeil off areas where it was once retained. Water pollution from hnill-ii/) and agricultural lands has led to a decline in the aquatic life of the Mackinaw since the 1950s. 66 Critical Trends in Illinois Ecosystems With the loss of oak woodlands, the plant and wildlife species that depend upon them are also gone. Along the upper and middle reaches of the Mackinaw, the channels are very stable, due in part to its tree-lined riparian zone. The lower reaches, however, are not as stable and contribute to increased sedimentation. Habitat loss - Nearly one-fourth of the fishes and mussels that once occurred in the Mackinaw live there no more, a direct result of habitat loss. The draining of wet- lands and removal of areas of clear, slow water (because of sedimentation, channelization, increased water velocity) has caused the golden shiner and the brown bullhead to disappear. Unstable bottom conditions, caused by sedimentation, have extirpat- ed certain species of mussels. This loss of habitat has been highest in smaller tributaries that pass through upland areas. The absence of fire also contributes to habitat loss. When fire is suppressed, changes occur in forest structure, composition, and diversity, for example, the invasion of sugar maples into oak- hickory forests. With the loss of oak woodlands, the plant and wildlife species that depend upon them are also gone. Habitat fragmentation - Notable examples of problems caused by fragmentation are increased songbird nest parasitism by cowbirds, interruption of migration patterns, and, ultimately, loss of songbird species diversity. Similarly, habitat con- nectedness is important for species such as amphibians, which often travel long distances between breeding and non-breeding habitats. Many habitats have been degraded by grazing. The palatable and often showy species such as trilliums, ferns, orchids, and belltlowers are gone. The unpalatable species (those that are thorn- bearing or have bristly fruits) are left to flourish. Many woodlands in the basin now have a ground cover of undesirable species like buckbrush. common snakeroot, brambles, and garlic mustard. Opportunities To create stable banks and thus reduce soil erosion, a wide band of vegetation should be planted along streams and rivers — natural vegetation deflects water from the bank, absorbs energ>- from the moving water, and results in a slower flow. Maintaining these forested riparian zones could enhance the suitability of the area as habiut for bobcats and gray foxes, and reducing silt and chem- ical n.m-<)ff will improve the abilit>- to attract and support river otters. Restoring prairie and prairie wetlands would benefit a variety' of amphibians and reptiles and enhance the suitabilit)' of the area as habitat for Kirtland's snake, the smooth green snake and the tiger salamander. Restoring native forests, wetlands, sand prairie and sand ponds in the sand>' southwest area would benefit two of the basin's T & E species — the Illinois chorus frog and Illinois mud turtle. Maintaining small temporar}' fishless ponds in forests — particularly upland forests which are among the rarest in the basin — would benefit almost all reptiles and amphibians, as well as other species that depend on them for food. Habitat loss has also been a major problem for birds in the basin; the area has few liigh quality- areas for breeding birds. Tlie Parklands natural area in the middle Mackinaw Ri\er sub-basin has the best potential for creating a large, forest-interior tract of 500 acres or better. This site already has veeries. northern paula. Louisiana water thrush and ovenbird. It is large enough to contain signific;mt areas of grassland and shrubland habitat. Restoring grasslands would bring back popula- tions of many threatened and end:mgered bird species. Sites should be relativ el> large (more than 100 acres) and dedicated to gnissland management. Wood) \egetation remo\ al (except in areas that are too wet to bum) may be necessar>- to attract some birds and increase their nesting success. Rotational mowing, burning or grazing may maximize the number of grassland birds that cim nest in an area. Spoon River Watershed 67 CHAPTER SEVEN Spoon River Watershed Tlie seventh largest of the 10 water- sheds, the Spoon is fairly average in most respects. It accounts for more than 10% of the statev^'ide acreage of upland forest, grassland and non-forested wetlands. (See page 106 for a color map of the watershed's land cover.) Portions of three Resource Rich areas lie witliin this water- shed — the Middle Illinois River, Peoria Wilds and Mississippi-Lower Rock. The Middle Illinois River RRA covers 899 square miles — 24% in the Spoon River watershed, 41% in the Sangamon and 35% in the LaMoine. It incorporates tloodplain and upland land- scapes along the Illinois River from just below Peoria to Florence. The third largest RRA. the site includes sand prairies, which have a mix of native tallgrass and plants more com- monly associated with the western U.S., such as the prickly pear cactus. • The Peoria Wilds RRA is 434 square miles — 42% in the Spoon River watershed and 59%> in the Kankakee — that encompass the floodplain of the Illinois River, deeply dissected bluffs and hills bordering the floodplain, and relatively flat agricultural areas away from the river. A large tract of forest runs along the bluff to the west of the river, and non-forested wetlands are concentrated along the river. One of the largest remaining oak wood- land areas in Illinois is found here. • The Mississippi-Lower Rock River RRA encompasses 715 square miles — 81% in the Rock River watershed and 19% in the Spoon River watershed. It includes major rivers, bottomlands, upland forests, prairies and river bluffs. The area has a relatively high total acreage of natural areas because of the Mississippi River sites. ECOSYSTEM MONITORING Based on the eight CTAP sites that were assessed, the Spoon watershed had the best average HBI scores of all ISIS basins and above average EI'T rich- ness. Conversely, native fish richness and habitat quality were below average. Most streams One of the largest remaining oak wooclUmd areas iti Illinois is found here. Table 26. Watershed Land Cover Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest 449,073 12.9% (3) Grassland 668,468 19.1% (3) Non-forested wetland 38,883 1.1% (3) Bottomland forest 53,777 1.5% (7) Water 47,706 1.4% (6) Urban/liuili-up 91,772 2.6% (5) Cropland 2,146,345 61.4% (5) Total acreage 3,496,028 100.0% 10.9% (4) 10.4% (5) 11.0% (4) 6.1% (6) 9.5% (5) 4.9% (6) 10.0% (7) 10.0% (7) * The watershed's iH-n entail' of the land cover ly/ie slaleiride. e.^. lO.'JX of the slate's iif)land foivsls are located in this watershed. Note: the watershed's rank ( Ist-IOth) is shown in /laren theses. 68 Critical Trends in Illinois Ecosystems sampled had severe erosion and sand deposition. Only one monitored stream had good habitat quality, David's Creek near Monmouth in Warren County. While the Edwards River had great EPT richness, the stream suffered from sand deposition to the extent that pools were relegated to narrow areas along banks. Table 27. Watershed Indicator Scorecard The watershed ranked either first or second among the ten watersheds in all four indicators. H CTAP-INHS River Sites © RiverWatcIn Sites A ForestWatch Sites Figure 44. Monitoring sites RiverWatch volunteers collected 74 samples at 34 sites on 29 streams. RiverWatch indicators suggest that the watershed's streams are among the best in the state. However, it should be noted that most of the sites monitored were located on streams that flow into the Mississippi or Illinois rivers rather than into the Spoon River itself The watershed ranked either first or second among the ten watersheds in all four indicators. Overall, the values reflect liigh macroinvertebrate biodiversity and only modest organic pollution. The average MBl value has decreased over the five-year period, indicating an improvement in stream c|iiality. However, the changes are not statis- tically significant. Indicator Watershed Value Statewide Value Watershed Ranking Macroin t 'ertehrates HBI 4.4 5.2 1 MB! 5.3 5.7 2 EPT richness 9r 7.1 1 EPT taxa (RW) 3.4 2.6 1 Taxa richness 9.5 8.9 2 Taxa dominance 77.5% 80.4% 2 Fish Native fish 10.8 13.6 9 Darter richness 1.8 19 5 Exotic species 0.0 0.2 1 Habitat Habitat score 83.8 88.6 - Table 28. MBl Values Statistic 1995 1996 1997 1998 1999 Cherall Average 5.92 5.25 5.38 5.15 4.9" 5.29 Standard deviation 1.36 0.81 0.98 0.63 0.82 0.93 Minimum 4.^1 2.69 341 438 3.18 2.69 Maximum 9.03 5.93 "28 6.37 6.61 9.03 Number of sites 9 14 16 13 16 (>8 * Only samples with at least 25 organisms were iiiclutied in the analysis REGIONAL ASSESSMENTS Two regional assessments hare been conducted in this watershed — for the Spoon Riter basin and the Illinois River Bluffs. Spoon River Basin The Spoon River rises in west-central Illinois near the small town of Neponset in southwestern Bureau Counrx'. For approximately the first 100 miles of its course, the Spoon parallels the Illinois River, then abruptly turns southwest- ward in Fulton ('ount>-. Within approximately 2S miles, the Spoon joins the Illinois Ri\er opposite the town of Haxana. Spoon River Watershed 69 The river basin encompasses a surface area of approximately 1,845 square miles and includes portions of nine counties. Most of the land is used for agricultural purposes, ranging from 97% in the upper reaches of the watershed to 55% in the lower Spoon. Prior to European settlement approximately 67% of the Spoon River area was prairie and the remaining 33% was timber Only 112 acres of prairie, 0.01%, remain in an undegraded, high- quality' ecological condition. The 2.4 acres of high qualit)' dr>'-mesic prairie found in the area accounts for 16.7% of such prairie remaining in Illinois. The basin's wet-mesic upland forest accounts for 18% of the total remaining in the state. >XTTile the original savanna acreage for the area is unknown, the area has a notable small remnant (0.7 acre) that accounts for 7.6% of all the high quality savarma in Illinois. It is the only remnant of a Grade A savanna in the state. Other significant features: • underground the region is literally a "coal mine" and 7.5% of the area contains contiguous areas of surface-mined land; • only 21 stream-miles of the Spoon have been channelized, making it one of the least channelized watersheds in Illinois; the area is rich in archaeological resources, with more than 2,600 sites recorded; a major archaeological museum, Dickson Mounds State Museum, presents the world of native Americans through 12,000 years in the Illinois River Valley. DEFG ■ A Cropland (64.5%) rm ^ ■ B Grassland (18.4%) n C Upland forest (13.4%) ■ D Urban/built-up (1.6%) °ttl B n E Non-forested ■ wetlands (1.0%) m □ F Bottomland forest ^^^^^^1 W (0.6%) ^^P Wh D G Water (0.6%) Figure 45. Sfxxm River basin land cover Plant and animal species Twenty-eight percent of the state's plants grow in tiie Spoon River basin, including the state-threatened bunch-flower, a lily found in wet to mesic prairies tliat occurs in .Vlassasauga Prairie Nature Preser\'c. Illinois endangered bird species that live in the area include the black-crowned night heron, northern harrier upland sandpiper and Hcnslow's sparrow. Threatened species include the red shouldered hawk, brown creeper, least bittern, and loggerhead shrike. Wliile several bird species have disappeared from the area, the wild turkey has been re-established. Basin acreage - 1,180,951 acres State land*- 2,399 acres Federal land - 1,671 acres Total natural areas - 2175 acres High-quality natural areas - 111.3 acres Nature preserves - 84 acres " Does not include natural areas or nature preserves that may be state owned. More than three-fourths of Illinois' mammal species are known or likely to occur in the Spoon river area. The river otter, once locally extinct, was reintroduced in 1996. One endangered reptile, the massasauga rattlesnake, is known to exist in the basin, but the state-threatened timber rattlesnake has been extirpated. Local economy and outdoor recreation Except for Peoria County, the area is mostl) rural. Between 1870 and 1990 the combined populations of Peoria, Fulton, Knox, Stark and Warren counties grew only 90%, compared to statewide grovk^h of 350%!. Not suqirisingiy, urbanized Peoria (>)unr\' had the greatest population increase, up 285%. Since the early 1970s, the area economy has changed steadily from a manufacturing base to a more service-related economy. In 1970, the ser\ice sector accounted for 19% of the area's jobs; by 1994, it accounted for more tiian one-third. Although manufacturing employment fell to 1 2% of area employment, it still accounts for more than 20% of all income, and Caterpillar in Peoria remains the largest employer The area has one state-owned outdoor recre- ation .site, .Snakeden Hollow State Fish and Wildlife Area. Restored from a Midland (ioal (;omiiany surface mine, the site encompa.sses 2,500 acres near Victoria in Knox County. Emiquon National Wildlife Refuge is a federally-owned site with 1,671 acres near the confluence of the Spoon anil Illinois The area is rich in archaeological resources, with more than 2.600 sites recorded. 70 Critical Trends in Illinois Ecosystems Maintaining the forested riparian zone along the Spoon River will enhance the suit- ability of habitat for the gray fox, bobcat, river otter, and amphibians and reptiles. rivers in Fulton County. When land acquisition is complete, the refuge will encompass approxi- mately 1 1 ,000 acres. Threats Habitat loss and fragmentation - Habitat losses for prairies and wetlands (only 1% of the land is in wet- lands) have exceeded the rates for the state as a whole, while forest habitat loss has occurred at a lower rate. In addition to habitat loss through conversion to cropland, most remnant plant communities in the Spoon River basin have experienced changes because of fragmentation, the absence of fire, and exotic species introduction. Tiling and flooding - Tiling agricultural land to improve drainage has a negative impact on streams. The rapid drainage increases the pulse of floods as well as the intensity and duration of low-flow once the water has moved downstream. Also, stream organisms are not adapted to these extreme water level fluctuations and whole populations can be extirpated. Sedimentation - The Spoon River watershed is the largest contributor of siltation to the Illinois River Because of this siltation, no parts of the Spoon are rated as high quality or as a Biologically Significant Stream. Opportunities To Improve bird management in the area, large tracts of forest are needed to offset fr-agmentation. One candidate is the Emiquon National Wildlife Refuge in Fulton County. Restoring grassland tracts of more than 100 acres would also improve prospects for re-introducing Franklin's ground squirrels and provide additional habitat for badgers and red fox. Restoring wet prairie, especially at the Massasauga Prairie Nature Preserve, would help birds as well as amphibians and reptiles. Restoring natural vegetation and maintaining riparian zones will improve water quality. Other recommentlations for the basin include: • protect both upland and floodplain forested tracts and maintain dispersal corridors such as the forested riparian zone along the Spoon River to enhance the suitabilit) of habitat for the gray fox, bobcat, river otter, and amphibians and reptiles; • manage developed areas, especially urban forests and parks, to improve bird habitat by encouraging oaks and leaving shrubby areas for migrants; • Ln agricultural areas, provide increased cover for wildlife with shrub-lined drainage ditches and unmowed roadsides. Illinois River Bluffs Located in west-central Illinois, the Illinois River Bluffs begin near Hennepin, where the Illinois River makes its 'big bend' toward the south, and ends at the southern end of Peoria Lake at East Peoria, taking in nearly 561,000 acres. This part of Illinois marks the furthest reach of the massive glaciers that crept from the north and east during the most recent ice age. As the ice walls melted, rock rubble piled up along their edges. The resulting moraines snake across today's landscape, running roughly north to south for dozens of miles. Streams sliced their way through these moraines on their way from the uplands to the Illinois River below, creating a picturesque terrain. Tlie mix of woodland. sa\-anna. and prairie found in the bluffs along the Illinois Ri\er is one of the largest remnant forest ecosystems left in Illinois. Tlie Illinois Ri\er Bluffs has more fi)rest than most parts of the state — more than one-half of its presettlement forest area remains wooded today, compared to 31''" statewide, and more of the forests retain their original ecological integrit>; 0.2% compared to 0.08% statewide. Other significant features include: • the Illinois River was one of three ri\"er-nood- plain ecosystems in the I'.S. given priorin- for restoration by the National Academy of Science National Research Council: • 2'"~,84^ acres have been designated a state Resource Rich Area; Spoon River Watershed 71 a number of natural communities that are rare or absent in the rest of the state occur here — more than half of the good-qualit>' glacial drift liill prairie, almost half of the seeps, and all of the tall shrub fen. F G ■ A Cropland (59.7%) D B Grassland (15.1%) ■ C Upland forest (13.8%) ■ D Non-forested wetlands (3.5%) D E Water (2.8%) D F Urban/built-up (2.6%) D G Bottomland forest (2.5%) Figure 46. Illinois River Bluffs land cover Plant and animal life Overall, the area is not a haven for rare species. Only 1.3% of Illinois' officially endangered species and 10.5% of its threatened species are found here. However, the valley does harbor rare plant species such as the decurrent false aster, which exists only in the Illinois River Valley, and Schreber's aster, found in Illinois only in and around the river bluffs. A little more than a thousand species of vascular plants (four of five of them are native) are known in the area, but only 10 appear on theT&E list. Basin acreage - 560,874 acres State land*- 9,475 acres Federal land - 1 ,622 acres Total natural areas - 2,459 acres High-quality natural areas - 501 acres Nature preser\'es - 1,300 acres * Does not include luitunil an'tis or mitiirv preserves that may be state owned. Some three dozen species of wetland birds are known to inhabit the region, including 16 species, such as the black peared at rates faster than the statewide a\erages. The losses continue as once-remote farms have acquired new value as building sites. Urban development has alread)' impacted some of the best remaining natural areas and threatens others as it sprawls north of Peoria. The valley serves as an essential cotriclor for transient species, including the federally-threatened bald eagle, the bobcat, and many migratory bird species. 72 Critical Trends in Illinois Ecosystems In general backwater lakes in the area have lost 70% of their capacity to sedimentation since settlement The area has more than 700 separate emergent wetlands, land covered with water shallow enough that plants rooted in the water grow mainly above it.The largest such wetland (in the Marshall County Conservation Area) is 74 acres, but the average wetland is 3- 1 acres. Forested wetlands are split into more than 800 separate parcels with a mean size of 13.8 acres — considerably smaller than the 500 acres thought necessary to provide safe breeding habitat for many forest birds. Pollution - A century ago Chicago decided to eliminate its water pollution problem by flushing it down the Illinois River By 1922 the Illinois River at Chillicothe was ecologically dead. Improved sewage treatment upstream has restored that part of the river to life but not yet to health; the pondweeds, coontail, and wild celery that once sustained flocks of hungry waterfowl on Peoria Lake, for example, never came back. Altered hydrology - Draining chronically wet soils makes them farmable, but it destroys some kinds of habitat and alters the way others function. While some amphibians adapt well to humanized envirormients — the bullfrog can use drainage ditches, flooded fields, even livestock watering troughs as breeding habitat — most species are not so opportunistic. The wet prairies preferred by the eastern massasauga snake have been dramatically reduced in extent since settlement, resulting in the snake's extirpation from the Illinois River Bluffs. Sedimentation - Siltation, increased water tem- peratures, and desiccation all follow when riparian vegetation is removed and fields are tiled for agri- cultural production. Excessive siltation is among the most damaging forms of stream pollution. In general backwater lakes in the area have lost 70% of their capacity to sedimentation since settlement. Opportunities To enhance habitat for breeding birds, existing large forest sites should be conserved. The Peoria Wilds Resource Rich Area, combined with wetlands in Marshall County, could turn the Illinois River Bluffs into a breeding source for other parts of Illinois. Studies suggest that prescribed fires can benefit bird species such as the northern oriole, summer tanager, rose-breasted grosbeak, and great crested flycatcher. The red-headed woodpecker, whose presence in the Midwest has declined nearly 2% a year since 1966, has also shown higher reproductive success in burned woods. The region could be made more welcoming to migrant birds that seek open woods by restoring degraded but still viable savanna. Small sites could be restored with native plant commimities. keeping in mind the needs of migrant birds. Protecting both upland and floodplain forested tracts and maintain- ing dispersal corridors such as the forested riparian zone along the Illinois River could enhance the suitability of the area as habitat for gray fox and bobcats. Remaining forests could be managed to maintain large snags for forest-dwelling bats and den sites for other mammals such as the southern flying squirrel. Existing wetlands should be preserved and they should be buffered h\ wooded and grassland strips. Wetlands or riparian forest restoration could attract river otters, and maintaining small wetlands would benefit almost all amphibi:m and reptile species. Also, maintaining small, temporar); fishless ponds in large forest tracts would benefit many of these species. For most amphibians, however, agricultural fields and \acant lots are barriers to dispersal. For these species to persist in die land- scape, small wetlands must be connected to other wetlands by corridors of natural vegetation. To provide valuable grassland habitat for birds, sites should be at least 100 acres, and be burned or mowed on a schedule that lea\es some areas unmanaged tor at least three years. Preser\ing native prairie and other grassland habitats would provide additional habitat for badger and red fox. Siltatii)n, desiccation. ;uid higher than normal temperature would all be reduced to acceptable levels if streams were lined with native plants that shaded the stream, stabilized the banks, and filtered sediment and chemicals from runoff before they reached the stream. Sangamon River Watershed 73 CHAPTER EIGHT Sangamon River Watershed Located in central Illinois, the Sangamon River watershed is the sixth largest ISIS watershed. It has the largest percentage of its land in crops, and has the second highest cropland acreage in the state. It has the small- est amount of upland forest and is the fourth most urbanized watershed in the state. (See page 107 for a color map of the watershed's land cover) Two Resource Rich Areas are in this watershed, the Sangamon River RRA and the Middle Illinois River RRA. • Relatively small at 84 square miles, the Sangamon River RRA is liighly agricul- tural. The major natural features are the Sangamon River and the forest tract at Robert Allerton Park, a relatively undisturbed stream-valley ecos)'stem which includes bot- tomland forest, upland forest, reclaimed prairie and wetlands. The Middle Illinois River RRA is 899 square miles — 24% in the Spoon River watershed, 41% in the Sangamon and 35% in the LaMoine. It incorporates floodplain and upland land- scapes along the Illinois River from just below Peoria to Florence. The third-largest RRA, the site includes sand prairies, which have a mix of native tallgrass and plants more commonly associated with the western U.S., such as the prickly pear cactus. ECOSYSTEM MONITORING CTAP biologists assessed seven streams in this watershed. EPT rich- ness was above the statewide average and habitat quality was higher here than in any Table 29- Watershed Land Cover Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest 163,812 4.4% (10) 4.0% (10) Grassland 458,121 12.4% (9) 7.1% (7) Non-forested wetland 27,496 0.7% (7) 7.8% (7) Bottomland forest 69,397 1.9% (5) 7.9% (5) Water 35,235 1 .0% («) 7.0% (8) Urban/built-up 121,360 3.3% (4) 6.5% (4) Cropland 2,827,500 76.4% (1) 13.1% (2) Total acreage 3,702,925 100.0% 10.2% (6) * The watershed's percentaf^e of the land cover type statewide, c.j?., 4% of the state's upland forests are located in this watershed. Note: the watershed's rank ( 1st- 1 0th) is shown in fxnvtdheses. 74 Critical Trends in Illinois Ecosystems Only seven shrub and vine stems were recorded from this site, five of which were invasive shrubs. other basin. However, native fish richness was com- paratively low. Many sites had wooded riparian zones, winding stream courses, well-developed undercut banks, and good variation in depth. Sugar Creek, near Armington, had high EPT richness and a low HBI score. The worst site was Horse Creek near Pawnee which had lower than average EPT richness and extremely low habitat quality. Cox Creek, a tributary of Panther Creek near ChandlervUle that drains part of the Jim Edgar Panther Creek State Fish and Wildlife Area had good habitat quality, above average EPT richness, but relatively high HBI scores. Over five years, RiverWatch \olunteers collected 47 samples at 30 sites on 28 streams. Monitoring indicates that the Sangamon watershed has near average stream health. The watershed had fairly average scores in MBI and EPT taxa, indices of organic pollution. With respect to macroinvertebrate diversity, the watershed scored well in taxa dominance and poorly in taxa richness. Overall, the most abundant taxa collected from the Sangamon River watershed were midge larvae, stonefly larvae and sowbugs. The stonefly is an EPT taxa that is particularly sensitive to pollution. Stream qualin- and the number of sites monitored varied considerably from year to year, making detection of trends difficult. Also, streams in the watershed are subject to frequent flooding and are not always accessible to volunteers. Table 30. Watershed Indicator Scorecard Indicator Watershed Value Statewide Value Watershed Ranking Mcicroiii I 'ertebrates HBI 5.1 S.2 4 MBI s.s s.- ■5 EPT richness 9.~ -.1 2 EPT taxa (RWO 2.8 2.6 S Taxa richness 8.4 8.9 8 Taxa dominance 79.3% 80.4% 4 Fish Native fish 11.- 1.V6 - Diirtcr riclincss 2.7 1.9 5 Exotic species 0.0 0.2 1 Hiibildl Habitat score III.O 88.6 1 CTAP- INHS River Sites ® RiverWatch Sites A ForestWalcti Sites Figure 47. Monitoring sites Sangamon River Watershed 75 Table 31- MBI Values Statistic 1995 199(> Wr 1998 1999 Ovcmll Average Standard deviation Minimum Maximum Number of sites 7.89 5.61 4.72 .S.99 5.69 5.47 3.21 1.48 2.23 2.84 136 1.81 5.63 2.22 2.40 1.99 3.09 1.99 10.16 9.72 9.18 600 7.75 10.16 2 20 9 2 9 42 * Only samples with at least 25 organisms were included in the analysis. ForestWatch volunteers monitored one site, an oak-hickor}' upland forest, in the Sangamon River watershed in the fall of 1998. Thirteen tree taxa were recorded at the site, slightly above the statewide average of 11.8 per site. Hickory and honey locust were the most abundant, and white oak and honey locust led in basal area and importance values (Table 32). Only seven shrub and vine stems were recorded from this site, five of which were invasive shrubs — two gooseberry' stems and three honey- suckle shrub stems. No sugar maples were record- ed at the site and oak and hickory trees seem to be replacing themselves. Although there were no signs of g>'ps)' moths or dogwood anthracnose, more sites are needed to determine if these pests arc present within the watershed. Table 32. Tree Species with the Highest Importance Values Importance Values Species % of total trees counted (n=138) % of total basal area (27.8m^Aia) 38 Honey locust 19% 19% 28 White oak group 7% 21% 25 Hickory 19% 6% 24 Black walnut 7% 17% 24 Hackberry 17% 7% 22 \XTiite oak 2% 20% 11 Black cherry 9% 2% 11 Osage orange 9% 1% 8 Tupelo 6% 2% 6 Post oak 3% 3% 3 Slippery elm \% 2% <1 Shingle oak 1% <1% <1 Pine 1% <1% 76 Critical Trends in Illinois Ecosystems CHAPTER NINE LaMoine River Watershed The watershed has three Resource Rich Areas — Big Rivers, Nauvoo and the Middle Illinois River Located on the western edge of the state, the LaMoine is the second- largest ISIS watershed with almost 4.3 million acres. It is the sec- ond-highest in the amount of surface water and upland for- est, and second-to-last in the amount of urban and built-up land. (See page 108 for a color map of the watershed's land cover.) The watershed has three Resource Rich Areas — Big Rivers, Nauvoo and the Middle Illinois River. • Located on the Mississippi River, the Nauvoo RRA is 235 square miles. Sharply dissected bluffs divide the low, level bottomlands along the river from the higher rolling uplands. The natural resources — woodlands, wetlands and natural areas — are mainly associated with the river. The Cedar Glen Nature Preserve is a sig- nificant roosting site for wintering bald eagles. • Big Rivers, at 979 square miles, is the largest of the Resource Rich Areas. It is characterized by a narrow band of bluffs and rugged topog- raphy that borders the floodplains of the Mississippi and Illinois Rivers. Forest is the predominant natural vegetation, but hill prairies are common on west-facing bluffs. Sinkholes and sinkhole ponds also occur here. • The Middle Illinois River RRA is 899 square miles — 24% in the Spoon River Watershed, 41% in the Sangamon and 35% in the LaMoine. It incorporates floodplain and upland landscapes along the Illinois River from just below Peoria to Florence.The third-largest RRA, the site includes sand prairies, plant communities which are a mix of native tallgrass and plants more commonly associated with the western U.S., such as the prickl}' pear cactus. ECOSYSTEM MONITORING Eleven sites were investigated by CTAP biologists. EFT richness, composed of taxa of moderate toler- ance to organic eitrichment. was slightly above the statewide average. Native fish richness was low, however. Habitat quality- was a little above average. Table 33- Watershed Land Cover Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest 720,848 16.8% (2) 17.4% (2) Grassland 780,215 18.2% (5) 12.1% (4) Non-forested wetland 25,767 0.6% (8) 7.3% (8) Bottomland forest 105,135 2.5% (4) 12.0% (3) Water 73,928 1.7% (2) 14.8% C2) Urban/built-up 59,918 1.4% (9) 3.2% (9) Cropland 2,521,457 58.8% (7) 11.7% (4) Total acreage 4,287,271 100.0% 12.0% (2) * The watershed's percentage of the land cover t\'pe statewide, e.g.. I''.-i% of the <;tate's upland foivsts aiv located in this watershed. Note: the watershed's rank (Ist-IOth) is shown in parentheses. LaMoinc River Watershed I 77 despite scores being lowered b)' the many streams that had bottoms of highly compacted clay, providing little habitat for fish and EPT species. The best streams were Hurricane Creek near White Hall and Little Indian Creek near Virginia, small drainages that had relativeh' high EPT, fish richness, and habitat quality'. The worst stream was the Left Fork Apple Creek near Franklin; the sampling site was near a fertilizer distributing company. Only two EPT and two native fish taxa were taken from this stream, which also scored poorly for habitat qualitv'. RiverWatch volunteers monitored 64 sites on 53 streams, collecting 1 57 samples over five years. Biological indicators suggest an average watershed. The watershed's taxa richness ranked sixth best, while taxa dominance ranked only eighth. The MBI and EPT taxa values were also near the mean. The most dominant taxa overall were midges, sowbugs, and scuds, all common organisms across the state. Although the MBI declined, the change is not statistically significant and no trends are evident. Table 34. Watershed Indicator Scorecard Table 35. MBI Values Statistic 1995 1996 1997 1998 1999 Overall Average 6.04 5.77 5.76 5.61 5.43 5.67 Standard deviation 1.03 0.77 0.86 1.36 68 0.97 Minimum 3.66 3.73 4.07 332 4.00 332 Maximum 8.63 7.17 8.00 9.6S 6.78 9.65 Number of sites 15 21 33 31 35 135 * Only samples with at least 25 organisms were included in the analysis. species. Twenty-one tree taxa were recorded in the watershed (75 taxa statewide). In general, the trees that were most abundant also had the highest basal areas and importance values (Table 36). None of the sites showed signs of maple takeover and oak and hickory trees seem to be replacing themselves. Within the watershed, there were no signs of gypsy moths, but one site had evidence of dogwood anthracnose — several flow- ering dogwood trees were dead or dying in the sampling area as well as elsewhere in the forest. Indicator Watershed Value Statewide Value Watershed Ranking Macroini ertebrates HBI 5.4 5.2 7 MBI 5.7 5.7 6 EPT richness 8.2 7.1 4 EPT taxa (RW) 2.5 2.6 7 Taxa richness 8.8 8.9 6 Taxa dominance 82.0% 80.4% 8 Fish Native fish 10.6 13.6 10 Darter richness 1.1 1.9 9 Exotic species 0.1 0.2 4 Habitat Habitat score 9^.8 88.6 3 In the fall of 1998, Forest Watch volunteers monitored three sites, all oak-hickory upland forests. During the previous spring, two sites were monitored. Tree species richness ranged from 9 to 1 5 species, with an average of 1 2 tree species per .site, similar to the statewide average of 11.8 H CTAP-INHS River Sites RiverWatch Sites A ForestWatch Sites GOMERY Figure 48. Monitoring sites 78 Critical Trends in Illinois Ecosystems Table 36. Tree Species with the Highest Importance Values Importance Value Species % of total trees counted (n=285) % of total basal area (19.6m2/ha) 52.8 Slippery elm 33% 20% 24.5 White oak 7% 18% 22.3 Flowering dogwood 12% 5% 21.3 Swamp white oak 7% 15% 17.8 Red oak 3% 16% 15.5 Hickory 12% 5% 7.8 Hackberry 5% 3% 7.8 Ash 4% 3% 6.5 Sassafras 5% 1% 6.2 Black cherry 5% 2% Gooseberry and multiflora rose were the only invasive species recorded, but they comprised more than 75% of the shrubs and vines recorded. The density of gooseberry was much liigher than the statewide average and one site had 50% of the gooseberry stems recorded statewide. During the spring survey, two disturbance-sensitive species — blue cohosh and large-flowered bellwort — were found at one site. No non-native invasive ground cover species were reported. 1 Non-invasive vines ^ P Statewide ■ LaMoine Non-invasive shrubs Japanese honeysucl' according to how much sunlight each receives. Other significant features: • one section of the Mississippi River — miles 232.5 - 241.5 in Calhoim County- — has been recognized as Bioiogicalh Significant because two state endangered species, the spectacle- case mussel and the western sand darter, are found there; • 626,795 acres have been designated a state Resource Rich Area; • one of the few remaining small, temporar>- forest ponds (free of egg-eating fish) is found in the John M. Olin Nature Preser\e in Madison County. LaMoine River Watershed 79 4!b ■ A Cropland (55.5%) ^ DB Upland forest (21.7%) c , \ 3 ^ n C Grassland (13.6%) ^ ■ D Water (3.1%) ^H D E Bottomland forest W '^ H F Urban/built-up (2.3%) B s --^ r D G Non-forested wetlands (0.7%) Figure 50. Big Rivers land cover Plant and animal life Although animal life has declined statewide since European settlement, it remains riclily varied here. The region is a haven for birds, largely because of its extensive tracts of upland and floodplain forests and riverine wetlands. The bird species that live in the area (at least 90% of the species found in Illinois) are ecologically diverse and, although some are able to live in a variety of habitats, many occupy only one or a few habitats. Thirty-three of them are on the T&E list and 23 of those breed in the area. Basin acreage - 1,133,172 acres State land* - 10,147 acres Federal land - 21,199 acres Total natural areas - 5,584 acres High-quality natural areas - 571.5 acres Nature preserves - 509 acres * Does not iiidiide natural areas or nature preserves that may be state owned. Among the rare plant species found here is the decurrent false aster, a federally threatened species. Two federally-listed endangered species, the Indiana bat and the gray myotis,are also found here, as is the state-threatened river otter. The largest venomous snake in Illinois, the timber rattlesnake, also makes its home here. Local economy and outdoor recreation Most of the Big Rivers area is rural and has experi- enced minimal population growth since early settlement. (Calhoun and (ireene counties have actually lost population in the last 120 years. Only Madison County, which is located in the St. Louis Metropolitan Statistical Area, has grown significantly. Its population grew five-fold between 1870 and 1970 — from less than 50,000 to about 250,000 — but has stabilized during the last two decades. More than 80% of Madison County is urban, while Calhoun County is entirely rural. In the five-county area urbanized land has grown 10% in the last ten years. Area employment growth has been slower than that experienced statewide, and Calhoun and Green counties both lost jobs over the past 25 years. Manufacturing has declined by one-third, although it continues to be the largest source of earnings. During the same time period, the services sector more than doubled in size and wholesale/retail trade grew by 50%.. In the more rural counties, farming continues to be a major employer; in Calhoun and Greene counties 19-28% of jobs are in agriculture. Outdoor recreation opportunities are shaped largely by the Mississippi and Illinois rivers. The river bluffs, marshes, backwater lakes, and wooded areas immediately surrounding the rivers provide the setting for several public recreation areas and for associated activities including hiking, wildlife viewing, fishing, and boating. The most frequently visited sites include Pere Marquette State Park, Beaver Dam State Park, Mississippi River State Fish and Wildlife Area, and the Mark Twain National Wildlife Refuge. The state sites contribute to the local economy, generating about %22 million in economic output and 320 jobs. Threats Physical alteration - Physical change has had a pro- found impact on the area. For example, grazing by cattle and other livestock kills many species of forest plants, and removing trees and other bank- side vegetation over-warms streams. Building drainage ditches or straightening streams speeds the flow of water from land into streams, aggra- vating flooding. Virtually all of Macoupin Creek west of Carlinville has been altered in this way. I lydrologic modification - The development of the water transportation .system on the Mississippi and Illinois rivers has led to a series of dams to create pools of sufficient depth to float today's barges. The "big rivers" have iieen iraiisfornud into Building drainage ditches or straight- ening streams speeds the flow of water from land into slreatvn theses. 82 Critical Trends in Illinois Ecosystems ECOSYSTEM MONITORING For the nine sites assessed by CTAP scientists, nearly all indicators were below statewide averages and none of the sampled streams were high quality. Most were agricultural ditches or urban drainage systems. The worst site was Copper Slough, which Table 38. Watershed Indicator Scorecard H CTAP -INHS River Sites © RiverWatch Sites A ForestWalcti Sites Figure 51. Monitoring sites runs through southwest Champaign. No EPT taxa were taken at this site, and habitat quality was poor. The RiverWatch biological indicator values confirm that the Kaskaskia River watershed is the most disturbed among the ten watersheds. RiverWatch volunteers collected 167 samples at 69 sites along 61 streams between 199^ and 1998. The Kaskaskia ranked nearly last in all measures of macroinvertebrate diversity and pollution tolerance. Even so, hydropsychid caddistly larvae, a com- mon and moderately pollution-intolerant EFI" taxa, were the most abundant macroinvertebrates. Statistical analysis showed no significant change in MBI values. Indicator Watershed Value Statewide Value Watershed Ranking Macroini'ertebrates HBI 5.0 5.2 3 MBI 6.0 5.7 8 EPT richness 4.9 7.1 10 EPT taxa (RW) 1.8 2.6 10 Taxa richness 7.7 8.9 9 Taxa dominance 85.9% 80.4% 10 Fish Native fish 11.3 13.6 8 Darter richness 0.7 1.9 10 Exotic species 0.3 0.2 6 Habitat Habitat score 76.1 88.6 10 Table 39. MBI Values Statistic 1995 1996 199- 1W,S !')<» 0\erall Average Standard deviation Minimiun Maximum Number of sites 6.82 6.18 6.02 5.5- 5.92 5.9'' -1.20 1.13 0.98 1.48 1.1- 1.24 3.85 4.39 3.~ l.-l 4.04 1 "1 9.78 8.6- 8.85 9.6l 8.73 9.-8 2 23 42 33 35 135 * Only samples with at least 25 organisms were included in the analysis. Tliirteen forest sites were monitored in Fall 1998 by Forest Watch volunteers. Eight were oak- hickory upland forests ;md five were ash-elm-maple bottomland forests. Tree species richness ranged from eight to 17 species, with an average of 12 species per site, similar to the statewide average of 1 1.8 species. Forty-three tree taxa were recorded in the watershed, the second-higliest in the state. In genenil, the trees that were most abundant also had the highest basal areas and importance values (Table 40). Exceptions are understory trees such as flowering dogwood and redbud that are numerous but not \ery large, theretbre not rating high for basal area or importance value. Two upland sites showed moderate signs of maple takeo\er At one of them, approximatel) 40 sugar maples within one hectare were greater than 40 cm in diameter Tliis may explain the prolifera- tion of smaller maples at the site — 8.^,^ maple seedlings per hectare that were less th;ui five Kaskaskia River Watershed 83 centimeters in diameter, about eight times the num- ber of smaller hickories. No oaks were found that were less than 5 centimeters. Table 40. Tree Species with the Highest Importance Values Importance Value Species % of total trees coimted (n=l,198) % of total basal area (24.4m-/ha) 31.0 White oak 9% 24% 25.8 Slippery elm 17% 8% 20.8 Hickor)' 12% 9% 17.5 Ash 7% 10% 16.0 Hackberry 11% 5% 8.4 Box elder 6% 2% 8.3 Red oak 2% 6% 7.0 Black walnut 3% 3% 5.7 Sugar maple 3% 2% 5.5 Pin oak 1% 4% There were no signs of gypsy moths, but one site showed evidence of dogwood anthracnose and another site showed possible anthracnose. This disease is becoming widespread in the state, and since flowering dogwood is a common species in the southern half of Illinois, it is likely that dogwood anthracnose is present in other forests in the watershed. Non-invasive vines Non-invasive shrubs Japanese honeysuckle Gooseberry MultHlora rose Honeysuckle 1 ■ Kaskaskia ■ Statewide 1 ^ ^■^^ - . ■ -W" 1 ^^ ■^i^^"r ^^^ Buckthorn Cranberry II 100 200 300 400 500 Slams (Mr hectare Figure 52. Number of iuvasit'c and non-invasive shrub and vine stems About 70% of the 688 shnib and \inc stems recorded were from invasive species, mostly honeysuckle shrub and multiflora rose. Of the 10 watersiicds, the Kaskaskia watershed recorded the second-highest abundance of honeysuckle. I'lie watershed also recorded more than 7()"ii (of 34 stems) of the Japanese honeysuckle found statewide. Additional monitoring will help delineate how widespread this species is. Spring monitoring at three sites recorded only two disturbance-sensitive ground cover species, maidenhair fern and Virginia spiderwort, both found at the same site. REGIONAL ASSESSMENTS One regional assessment has been completed for this watershed — for the Sinkhole Plain. Sinkhole Plain The Sinkhole Plain encom- passes the karst area in southwestern Illinois near the Mississippi River. Karst areas are characterized by easily erodible carbonate bedrock, which promotes the formation of caves and sinkholes. Rather than draining to a stream, water often slips through innumer- able sinkholes directly into groundwater. The Sinkhole Plain and its environs cover about 1,228 square miles in southwest Illinois, including all of Monroe County, much of St. Clair, and portions of Randolph and Madison counties. Bordered by two major rivers — the lower Kaskaskia River to the east and the Mississippi to the west — the region has examples of virtually every habitat known in Illinois, from floodplains lined by bluffs of exposed bedrock to prairies and wooded ravines, sluggish rivers and clear-running springs. 84 Critical Trends in Illinois Ecosystems Basin acreage - 785,821 acres State land* - 20,070 acres Total natural areas - 7,177 acres High quality natural areas - 1,215.5 acres Nature preserves - 854 acres ■ Does not include natural areas or nature preserves that may be state owned. About 60% of the land in and around the Sinkliole Plain is used for agriculture of one kind or another. This is less than in Illinois as a whole, where nearly 78% of the land is farmed. The region also has proportionately more trees, more wet- lands, and twice as much urban and built-up land than does Illinois on average. Other significant features: • about 44% of the presettlement-quality flood- plain forest still standing in Illinois is found in the region, as is more than a tliird of all south- ern flatwoods (in the Marissa Woods Nature Preserve in St. Clair County) and about 43% of the high-quality limestone glades; • two watercourses have been recognized as Biologically Significant Streams — a tributary to Horse Creek in Monroe County and a six- mile stretch of the Mississippi River in Randolph County; • nearly half of Illinois' surviving loess hill prairie is here and the 532-acre Fults Hill Prairie Nature Preserve in the Mississippi bluffs of Monroe County contains the largest complex of undisturbed prairie of this t)'pe in Illinois; • 291,305 acres have been designated a Resource Rich Area. ■ A Cropland (48.4%) n B Upland forest (15.8%) D C Grassland (14.4%) 13 D Urban/built-up (11.0%) ■ E Bottomland forest (4.7%) D F Water (3.2%) D G Non-forested wetlands (2.5%) Plant and animal life The region harbors 75 plant and animal species whose survival is threatened or endangered, includ- ing five species whose survival is at issue not only in Illinois but in the U.S. as a whole. The western sand darter, an Illinois endangered species, is fairh' common in clear sandy runs of the upper Mississippi, but outside of that setting it survives in only a few places, including the Mississippi River just south of Prairie du Rocher Among the mammals known from the region are the Indiana bat and river otter, whose survival in Illinois is considered to be endangered or threatened. Other rare species include the Illinois chorus frog, the coach- whip snake, the timber rattlesnake, and the eastern massasauga. Illinois' largest colonies of snow\- egrets and little blue herons are found here, along with some of the largest colonies of great egrets and black-crowned night herons. A few pre\iously extipated species such as the double-crested cormorant (which nest on the edges of backwater lakes along the Mississippi), the wild turkey, and the bald eagle have been re-established in recent years. Other bird species are still present but no longer breed here, among them the trumpeter swan, osprey, least tern, and \ellow-headed blackbird. One of Illinois' rare aquatic worms (a sludge worm) dwells only in springs found at two sites in Monroe Counts' and one site in St. Clair Coiuit\. The Illinois cave amphipod is found only in the ca\es of the Sinkhole Plain and was recenth listed by federal authorities as an endangered species. Figure 53- Sinkhole Plain land cover Kaskaskia River Watershed 85 Local economy and outdoor recreation Since 1870 the population of the Sinkhole Plain area has grown 277% (compared to 350% statewide), and now accounts for 2.8"o of the state's residents. Nearl)- all growth occurred in urbanized St. Clair Count)-, wliich grew steadily until 1970, when population began falling. Not surprisingly, St. Clair Count)' accounts for about eight-tenths of the area's employment and earnings. >X^iile the sersice sector is now the largest empIo>er in the area, government earnings remain strong. Tlie area is home to five major state-owned recreation sites. Frank Holten State Park is an urban site near East St. Louis featuring a golf course and expansive picnicking facilities. It hosts over a half- million visitors each year. Horseshoe Lake State Park. Kaskaskia River State Fisli and Wildlife Area, and Peabody-River King State Fish and Wildlife Area are directed towards fishing and hunting enthusi- asts. Illinois Caverns State Natural Area receives fewer visitors, but provides an example of the area's unique topography. Collectively, the 850,000 visitors to these sites generate $9.1 million in economic output and 140 jobs each year. Threats Pollution - Much progress has been made in reducing pollutants that enter area rivers and streams from point sources' like factories and city sewer systems. Nonetheless, in general water qualit)' in the region's streams and rivers remains onh' fain While groundwater is generally safe, the pecu- liar geology- of the Sinkhole Plain poses unique risks of contamination. Water moves freely into and through the shallow limestone nearly as freely as water moves through a tile drain, taking mere hours to cover distances that take da)s or weeks in less porous formations. Water entering these rocks is not filtered or chemically buffered by slow seepage through upper layers of clays and sands, as is the case in many parts of Illinois. As a result, there is a significant threat of contamination by pollutants spilled, dumped, or stored on the surface, from .septic field discharges, road nmoff, and pesticide and fertili/er runoff from farm fields. A recent four- year Illinois Stale deological Survey stud\' .sampled wells and springs throughout the Sinkhole Plain, and foimd that in the summer months 55% of 29 private wells drilled into bedrock ct)ntained higher- than-recommended levels of coliform bacteria, a common indicator of fecal wastes. Erosion - Much of the soil displaced by erosion ends up in streams, lakes, and ponds, often in such quantities that soil becomes, in effect, a water pol- lutant. The packed sand and gravel bottom of the lower Kaskaskia, where that river nears the Mississippi, is buried each summer beneath fine silt as much as a foot deep. Erosion from fields has been much reduced since the 1980s. By 1997 nearly six of ten farm acres were losing soil no faster than it was being replaced by nature. This is a relatively sizable pro- portion, given how vulnerable the sloping farmland is to erosion. Habitat fragmentatit)n - Once-extensive wet- lands, forests, and prairies have been fragmented into small habitat "islands". The developed land often becomes a barrier to animals mo\ing between habitats. The great plains rat snake, a denizen of the Mississippi bluffs from I'ults to Renault, is undisturbed within the liilts llill Prairie Nature Preserve. Many of these snakes, however, are killed b\ traffic when the\ attempt to cross the roads that di\'ide their larger habitat, of which the nature preserve is only a part. Plant populations in these splintered habitats become so small that they are Miiner.ible to disease and genetic weaknesses, a result of in-breeding, ihe Illinois Caverns State Natural Area receives fewer visitors, but provides an example of the area's unique topograpfjy. 86 Critical Trends in Illinois Ecosystems Bobcats, which have been sighted in Randolph and Madison counties since the 1980s, require extensive and varied terrain and cover region in and around the Sinkhole Plain still boasts a liandful of sizable forested tracts — the two largest are about 1,250 acres each — along the Mississippi and Kaskaskia rivers. However, the mean size of surviving tracts of contiguous forested bottomland is 19 acres, vastly smaller than the 500 acres thought to be the minimum-sized woods capable of sheltering nesting songbirds. The 173 acres of loess hill prairie iii the region is split into 12 sites. The more than 3,000 emergent wetlands include a few large ones on the Mississippi near the former site of Valmeyer and near Fults, but the mean size of emergent wetlands is only 4.1 acres. Hydrology - Paving once-porous surfaces and installing storm drains concentrates runoff from rains and melting snow, making bigger floods out of less water. The lower Kaskaskia River has always tended to flood. Carlyle Lake was built in 1969, 50 miles upstream from the Kaskaskia's confluence with the Mississippi, to catch and hold water that used to overwhelm downstream parts of the valley. The lake has caused noticeable reductions in peak water flow downstream. Carhle not onl\ lowers flood peaks but boosts flows during droughts when water is released from the reservoir. The remodeling of the watershed in and around the Sinkhole Plain has tended to aggravate the effects of drought. Drained farm fields speed the flow of water into nearby streams. This water used to soak slowly into the soil, building up subsoil moisture that fed streams for weeks or months. As a result, droughts that once merely reduced flow through the regions upland creeks now cause them to dr>' up completely. In low-water seasons, most of the flow of some streams like Richland Creek is effluent from sewage treatment plants. Opportunities Several large tracts of forested land along the Mississippi in Monroe and Randolph counties and the more than 15,000 acres in the Kaskaskia River State Fish and Wildlife Area have potential as breed- ing grounds tor birds that could populate the rest of the region. Bobcats, which have been siglited in Randolph and Madison coimties since the 1980s, require extensive and varied terrain and cover; the Kaskaskia River corridor and the forested bluffs in Monroe Count)' offer suitable habitat. In addition, the State of Illinois has been releasing river otters from Louisiana in Illinois river systems, including sites near the Sinkhole Plain. Embarras and Vermilion Rivers Watershed 87 CHAPTER ELEVEN Embarras and Vermilion Rivers Watershed Located in east-central Illinois, this watershed has a little more than three million acres, ranking it eighth among the 10 ISIS watersheds. It has the least amount of aquatic acreage (water plus non-forested wetlands) of the 10 watersheds; less than one per- cent of the watershed is covered by water. It is second-to-last in grassland acreage and has the smallest percentage of land in grassland. It is third among the 10 watersheds, however, in the percent age of land devoted to crops. (See page 110 for a color map of the watershed's land cover.) Three Resource Rich Areas are located within this watershed — the Upper Wabash River, Embarras River and Vermilion River. • The Upper Wabash River RRA encompasses 267 square miles of the Wabash River mainstem from where it enters Illinois to just above Lawrenceville, and the narrow band of small tributaries to the river. In this area the Wabash River is wide and slow flowing with sand- gravel substrate. It is one of the last relatively unaltered big rivers in the Midwest. • The Embarras River RRA includes the entire length of the river. Rich species diversity and a variety of habitats such as gravel bars, gravel-sand raceways, sand- bars, riffles, and deep pools are the outstanding features of the river, particularly in the middle sections. The area, encompassing 700 square miles, is one of the most agricultural among the RRAs. • The Vermilion River RRA (207 square miles) is located on a level glacial plain that in presettlement times was covered with prairie, with occasional savannas on the uplands and forests along the streams. Unusual terres- trial features include seeps, beech-maple forests and hill prairies. A segment of the Middle Fork of the Vermilion is Illinois' only stream designated as a National Wild and Scenic River. Table 41. Watershed Land Cover Land Cover Acres Percent of Watershed Statewide Percentage'* Upland forest 292,549 9.5% (7) 7.1% (6) Grassland 378,123 12.3% (10) 5.9% (9) Non-forested wetland 9,413 0.3% (10) 2.7% (10) Bottomland forest 52,692 1.7% (6) 6.0% (7) Water 14,665 0.5% (10) 2.9%. (10) Urban/built-up 74,978 2.5% (7) 4.0% («) Cropland 2,243,955 73.2% (3) 10.4% (6) Total acreage 3,066,378 100.0% 8.5% (8) A segment of the Middle Fork of the Vermilion is Illinois' only stream designated as a National Wild and Scenic River. * The watershed's percentage of I In- land corcr type slaleiride. e.g., 7 /% of the state's upland foivsts are located in this watershed. Note: The watershed rank ( Isl-iotb) is .shown in parentheses. 88 Critical Trends in Illinois Ecosystems ECOSYSTEM MONITORING The 10 sites sampled by CTAP biologists scored below average for HBl and about average for habitat quality, but had the best scores for EPT and native fish species richness. Several sites were large streams in the Embarras drainage where a shifting sand bottom predominated. However, snags (wood debris) and undercut banks were plentiful, providing stable habitat for a large number of EPT and fish species. Because the larger streams have a tendency to flood, row crops are kept further from their banks, allowing for meandering, wooded H CTAP -INHS River Sites RiverWatch Sites A ForestWalch Sites Figure 54. Monitoring sites riparian corridors. Smaller streams, however, have been cleared of trees, wood, and natural bimk struc- tures to facilitate drainage for row crops. The best site was the Embarras River at Fox Ridge State Park, where native fish and EPT richness and habitat scores were well above statewide and basin averages. An unnamed tributary of Freept)rt Creek near Oblong, channelized long ago but now heavily wooded, had EPT and native fish richness well below statewide and basin averages. This situation suggests a fairly recent spill event that was either toxic or depressed oxygen levels enough to kill sensitive insects. Table 42. Watershed Indicator Scorecard Indicator Value Watershed Value Statewide Ranking Watershfd Macioimertebrales HBI S,S S.2 8 MBI 6.0 5." 9 EPT richness 13.8 -.1 1 EPT taxa fRW) 3.3 2.6 4 Taxa richness 10.0 8.9 1 Taxa dominance 79.7% 80.4% S Fish Native fish 19.3 13.6 I Darter richness 33 1.9 1 Exotic species O.I 0.2 4 Habitat Habitat score 87.6 88.6 6 RiverWatch volimteers monitored 43 sites on 32 streams between 1995 and 1999. collecting a total of 86 samples. The watershed scored high in taxa richness but low in MBI. indicating that the organisms found there are generally pollution toler- ant. It ranked near the average in EPT taxa and taxa dominance. The hydropsy chid caddisfl) lar\a was the most common taxa in the watershed, followed by the midge and the riffle beetie.The riffle beetle is more common here than in the other watersheds. The average annual MBI indicates no significant changes in stream qu;ilit\' over the five years. Table 43. MBI Values Statistic 1995 1996 199- 1998 1999 Overall Mean 6.40 5.78 5.93 5 41 6.09 5.90 Standard deviation 1.>S8 11" 1.55 ()(i6 1.45 1.46 Minimum 3.49 3.91 4.48 4.^6 4.92 3.49 Maximum 10.5"' 8.44 9.16 6.73 9.74 10.5^ Number ol .sites 19 1~ 9 9 11 65 * Only samples with at least J5 organisms were included in the iiiudysis. In the fall of 1998 ForestWatch volunteers monitored six sites — five oak-liickor)' upland Embarras and Vermilion Rivers Watershed 89 forests and one ash-elm-maple bottomland forest. Tree species richness ranged from seven to l6 species, with an average of 1 2 tree species per site, similar to the statewide average of 11.8 species. A total of 34 tree taxa were recorded. Two sites showed some sign of maple takeover, with one of these having a few large sugar maples. Table 44. Tree Species with the Highest Importance Values Non-invasrve vines Non-invasive shrubs Importance Value Species % of total trees counted (n=616) % of total basal area (28.4m^Aia) 51.4 Hickor)- 29",, 20"„ 25.8 Red oak 9% 14% 24.3 Sugar maple 1.3".. 16% 15.1 White oak 8",. 8".. 13.6 White oak group 3% 10% 8.8 Ash 4% 5% 8.4 Oak species 3% 5% 6.4 Slippcn elm 6% 2% 4.4 Flowering dogwood 6% 1% 4.0 Pin oak 1% 6% There were no signs of g)'psy moths, but two sites had evidence of dogwood anthracnose. At one of these sites, nearly all of the dogwood trees showed symptoms of the disease. It is likely that more areas within the watershed have anthracnose since flowering dogwoods are relatively common and the disease is becoming widespread. Only 41 shrub and vines stems were recorded from all the sites. Of these, 53% were invasive species, the .second lowest amount in the state. None of the inva.sive species present seemed dense or a .serious threat at this tinic, lint more sites arc needed to determine their extent. 200 300 Stems per hectare Figure 55- Number of invasive and non-invasive shrub and vine stems REGIONAL ASSESSMENTS Two regional assessments have been completed for this area —for the Embarras River Basin and the Illinois Headwaters. Embarras River Basin The Embarras River is the second-largest Illinois tribu- tary (194 miles) of the Wabash River. Its basin comprises 2,440 square miles, with the northern half falling within the Bloomington Ridge Plain — hilly, morainal ground — and the southern half mostly within the Springfield Plain — a flat landscape. Dominated by agriculture, the basin has onl)' a minuscule amount of original high quality prairie left (0.0002%) and onl>' about 30% of the presettlement area of forest, and the amount that is old-growth is vanishingly small. However, 1 1% of wetlands remain, more than the statewide average. Other .significant features: • five state-designated nature preserves offer hill prairies, till plains, marsh, .sandstone outcrops, prairie-chicken habitat, cxjiosiires of Ice Age sediments, and wet-mesic I'loodplains; • well over half of the Embarnis Rivers main .stem — two sections totaling II2.S miles, the 90 Critical Trends in Illinois Ecosystems In general, habitat losses in the region appear to exceed rates for the state as a whole. second-highest in the state — is designated a Biologically Significant Stream; the middle section of the river is considered outstanding because it has a high species count and a diversity of habitats, including sandbars, gravel bars, raceways, riffles, and silt-bottomed pools: in general, the basin's aquatic life is in better shape than elsewhere in the state; 447,925 acres have been designated a state Resource Rich Area. defg m A Cropland (73.5%) c^ ■ ^^ n B Grassland (11.5%) ■ ^^^ D c Upland forest b/ ^\ ■ ^^H i (10.4%) v™ ^^H 1 O D Bottomland forest ^ ■ 1 (2.2%) 1 ^^^^^^H f °^ Urban/built-up (1.8%) 1 ^ P ' ■ F Non-forested wetlands (0.3%) K D G Water (0.3%) Figure 56. Embarras River basin land cover Plant and animal life At least 50 state threatened and endangered plant and animal species occur in the region. Some of these species occur only in natural areas or nature preserves because there are very few other places with suitable habitat. The four state endangered plant species include the water penn^-wort, run- ning pine, halbred-leaved tearthumb, and royal catchfly. The primitive, spore-bearing rumiing pine is restricted to a single locale, a seep springs in Red Hills State Park. Endangered bird species found here include the short-eared owl, Henslow's sparrow, American bittern and barn owl. among others. Of the 147 recorded breeding birds, 47 are now either locally extinct or are extremely rare during the breeding season, suggesting that habitat loss is a major problem in the area. At least two locally extirpated species, the greater prairie chicken and the wild turkey, have been reestablished in the basin. Of the eight mammal species listed as endan- gered or threatened in Illinois, the Indiana bat (also federally endangered) has been reported in the Embarras basin as has the river otter (state threat- ened). The insect fauna of the area, particular!)' butterflies and skippers, are poorly known. But it is likely that at least 74% of the butterflies and 64% of the skippers that occur in Illinois also occur in the Embarras basin. Local economy and outdoor recreation The Embarras basin is overwhelmingly rural, with only one city, Charleston, approaching a population of 20,000. Tlie nine main counties through which the Embarras and its tributaries flow contain only 1.6% of the state's population. Currently, the area economy supports some 95,000 workers and creates $31 billion in personal income. Farming remains importimt — farm employment's share of the total is generall)- four times and in some counties eight times greater than the state average of 2%. The dominance of cropland nor^ithstanding. the Embarras River basin contains a \arier\- of parks which offer open-air recreation such as boating, canoeing, horseback riding, hunting, fishing, and camping. Visitors to state-run lands create 515 million in annual economic acti\ir\'. Threats Habitat loss and fragmentation - In general, habitat losses in the region appear to exceed rates for the state as a whole and habitat ^^•hich remains is often fragmented. For example, the basin contains stands of Ibrcst and small sections of preserved i>r restored prairie that tend to be separated from one another by large areas of farms and some industrial and urban land. These small, insular habitats often contain a relatively high number of nati\c plant and animal species, with each species prone to at least Embarras and Vermilion Rivers Watershed 91 local extinction because it is represented by only a small number of individuals. Stream alteration - The widespread introduc- tion of agricultural tiles, together with substantial channelization — 16% of the stream miles in the basin are channelized — has created new ecologi- cal challenges. Both of these modifications promote higher stream velocity', pronounced downcutting, increased sedimentation downstream, and the potential for more destructive flooding. As a result, the Embarras and its feeder streams contain zones of severe bank erosion. Basin acreage - 1,541,523 State land* - 4,171 acres Total natural areas - 5,719.6 acres High-qualit)' natural areas - 379.4 acres Nature preserves - 252 acres * Does not include natural areas or nature preserves that may be state owned. Water quality - Of the 811 river miles (30% of the basin) assessed by the Illinois Environmental Protection Agency, almost half, 45%, were designated as "full support", meaning they met all applicable water quality' standards. Another 46% were determined to be impaired to a minor degree. Two percent (15 miles) were severely impaired. In certain areas, such as the North Fork and the headwaters above Lake Charleston, oil field pollution and siltation have been identified as water quality problems. Non-native species - A few aggressive exotic herbaceous plants have had a significant impact on more stable habitats in the basin. In the waters of the Embarras and its tributaries, the introduced common carp has destroyed aquatic vegetation by rooting about in the substrate and increasing turbidity, and by consuming .sources of food that would otherwise be available to native tlsh. Avian invaders such as European starlings have harmed native bird populations by stealing nesting cavities. Their effect is particularly serious in the small lots of woodland that typicalh remain after large forest tracts are fragmented. Opportunities Strategies to restore and manage biodiversity in the region include: • identify the distribution, abundance, and qualitative condition of remnants among several natural community classes, particularly prairie communities, • slow or minimize habitat degradation by removing the source, such as grazing, • restore habitats to high quality' condition by using intensive vegetation management, • reverse exotic species invasion with appropri- ate control measures, such as controlled burns, • stabilize stream banks with natural materials and native vegetation, and establish native grassland buffers along drainage ditches and other waterways where needed, • identif>' and promote restoration of suitable wetland habitat and promote side stream storage such as sloughs and backwater lakes. Conservation programs and projects are already underway to protect and enhance the ecology of the area. For example, the Jasper County Prairie Chicken Habitat is restoring the once- substantial prairie-chicken population. Illinois Headwaters The Headwaters area is per- haps unique in all of Illinois. Centered in c:hampaign and Ford counties, it is one of the flattest parts of the state. It is characterized by glacial topography, with the flat areas separated by glacial moraines that serve as drainage divides. This causes water to flow downhill in most directions, giving rise to six — the Vermilion, Embarras. Sangamon, Mackinaw, Kaskaskia.and little Vermilion rivers — that together drain almost one third of the state. Because of the brief lime since the retreat of the last glaciers, the Headwaters area has undergone comparatively little erosion. major streams 92 Critical Trends in Illinois Ecosystems The streams that originate in the Headwaters area are among the most pristine and scenic in the state. The streams that originate in the Headwaters area are among the most pristine and scenic in the state, and even though agricul- ture is the dominant land use, a surprising diversity of natural communities can still be found here. These include seven types of forest, five kinds of prairie, four types of savanna, plus seeps and cUffs, many of which are protected in the region's 15 nature preserves. However, forests of all types cover only a little more than 2% of the land area of the Headwaters compared to more than 11% statewide, and wetlands cover only 1% — about 11,500 acres of floodplain forests, shrub swamps, seeps, ponds and lakes. Other significant features: • the Middle Fork of the Vermilion River is the first Illinois river to be included in the National Wild and Scenic River System; • 1.3% of the Headwaters has been set aside by the state and counties as parks, fish and wildlife areas, or forest preserves; • two hundred and twenty-five miles of six Headwaters streams (the Middle Fork and Salt Fork of the Vermilion River, Jordan Creek, Stony Creek, the upper Sangamon River, and Lone Tree Creek) have been recognized as Biologically Significant because of their fish and mussel diversity; • 167,101 acres have been designated an Illinois Resource Rich Area. qDEFG ■ A Cropland (82%) D B Grassland (11.3%) H C Urban/built-up (3.1%) ■ D Upland forest (2.2%) D E Bottomland forest (0.7%) ■ F Water (0.4%) n G Non-forested wetlands (0.3%) Plant and animal life At least 46 species of state-threatened or -endan- gered plants and animals occur in the area, including two species (Indiana bat and clubshell) that are federalh' endangered Basin acreage - 1,072,198 State land* - 7,005 acres County land - 6." 10 acres Total natural areas - 3,~12.6 acres High quality natural areas -251.4 acres Nature preserves - 236 acres * Does not include natural areas or nature preserves that mar be state owned. Significant populations of all the songbirds common to this part of the world, from yellow- billed cuckoos to great crested flycatchers, can be found in the Headwaters, as well as endangered or threatened species such as the American bittern, black-crowned night heron and red-shouldered hawk. Forests host locally rare species such as the wood thrush, American redstart, barred owl. and summer tanager. Figure 57. Illinois Headwaters land coivr Of the seven fish considered threatened or endangered, the bluebreast darter occurs in Illinois onh' in the tributaries of the N'ermilion River. Endangered plants include the Sangamon phlox and Wolf's bluegrass. Local economy and outdoor recreation Although most of the Headwaters area (Champaign and Ford counties) is rural and agricultural, the metropolis of ("hampaign-l'rbana dominates the central part of the area, with 100.000 of the area's Embarras and Vermilion Rivers Watershed 93 187,000 population living in these two cities. Champaign and Urbana grew ver>' rapidly following World War II. a time when the University- of Illinois became increasingl)- important to the area. From 1969 to 1993, the area experienced slightly higher employment growth than did the state as a whole, and personal income growth averaged 1".. anmialh- Both Ford and Champaign counties are among the top five counties in the portion of land that is farmed, with nearly 85% of the land area in agriculture. The 2,000-plus farms in the area produce high yields of both corn and soybeans — Champaign Counry currently ranks second in the state for crop cash receipts. However only 2% of the area workforce is engaged in farming and farm earnings accounted for 1% of area earnings in 1993. a drop of 60% since 1969. More than 13,000 acres have been set aside by the state or the various counties as state parks (Kickapoo), fish and wildlife areas (Middle Fork), or forest preserves. Threats Habitat Loss - In general, habitat loss to cropland appears to exceed rates for the state as a whole. Before settlement, 1S% of Headwaters land is thought to have been forest and almost all the rest supported grassland ecosystems such as prairie and savanna. Today, only about 2'% of the land remains in forest, buildings and roads take up nearly i"... and slightly more than 2% is open water and wetlands. Almost all the rest is agricultural land. Absence of fire - Naturally-occurring fires in Headwaters woods and fields have been suppressed to protect fields and buildings. However, the composition and striicliirc of many native plant communities demonstrate some level of fire dependency, and fire absence in these com- munities can result in profoimd changes, such as converting from prairie to shrub thicket or forest. Fragmentation - Construction of roads, fields, and houses divide forests, wetlands, and prairies into habitat "islands." Lsolatcd habitat fragments often cannot supply the resources needed by species with extensive home ranges. Some species are unable to disperse among these isolated frag- ments, which increase their risk of becoming locally extinct. For example, prairie and savanna remnants in the Headwaters are often less than one acre in size. The entire populations of some plant and animal species in these tracts may include only a few individuals; the smaller such local popula- tions, the more vulnerable they are to disease and in-breeding stress. Drainage - One of the most significant changes made to the Headwaters ecology is a massive artifi- cial drainage system.Today, some 65-70% of the land in Champaign and Ford counties is underlain with tiles which empty into an extensive network of surface drainage ditches. Not since the glaciers retreated has any single hydrologic change so affected the Headwaters region. Populations of wet- land species have declined, and a few species are no longer found here due to the draining of prairie marshes. Wet prairies, once so common, today are not found at all within the Headwaters region. Opportunities Even though the Headwaters area is one of the most intensively farmed regions in the state, existing public holdings are relatively large and often contiguous. Habitat quality for birds is fairly good and has the poten- tial to get better. For example, to improve habitat for breeding birds forests could be restored where they would con- tain at least a 5()()-acre core. There are several sections along the Middle Fork River that could be Prairie and savanna remnants in the Headwaters are often less than one acre in size. 94 Critical Trends in Illinois Ecosystems Patches of available grassland habitat in the area have potential for restoration. enlarged by allowing regeneration of oak forest on ridgetops and along the old floodplain terrace. Grasslands should be at least 100 acres, should be burned or mowed on a schedule that leaves some areas unmanaged for at least three years, and should contain small wet- lands. Even though patches of available grassland habitat in the area are small and heavily used, they have potential for restoration. Many are grassy strips along roads that, if planted in appropriate species and managed to delay mowing until fledglings are out of nests, can boost populations of grassland birds such as the grasshopper sparrow and the Eastern meadowlark. Other opportunities for restoration: • restore forested wetlands, as well as grassy- wetlands, especially sedge meadows and marshes and along margins of lakes to benefit a variety of amphibians and reptiles; • improve forest corridors that link larger wooded areas in the Headwaters river \alle\s to make extensive habitat available to far-ranging animals; • protect forested riparian corridors and reestablish trees along banks to make ri\ers and streams more suitable as river otter habitat and to benefit other species that use these zones for foraging (e.g. bats) and as travel routes; • reduce silt and chemical run-off into wetland habitats; • maintain Ashless upland ponds and wetlands to benefit both of the state-listed salamanders found in the region; ponds in upland forests would be particularly valuable because these habitats are among the rarest in the area. Little Wabash River Watershed 95 CHAPTER TWELVE Little Wabash River Watershed The Little Wabash is the smallest of the 10 watersheds and has the smallest amount of both cropland and urban and built-up acreage. Because of its small size, it ranks near the bottom for statewide acreage in most of the other land cover categories, except for bottomland forest, of which it has the fourth largest amount. (See page 111 for a color map of the watershed's land cover.) Two Resource Rich Areas are in the watershed, the Lower Wabash River RRA and the Southern Till Plain RRA. The 256-square-mile Lower Wabash River RRA includes the mainstem of the Wabash River below LawrencevUle to its conflu- ence with the Ohio River and its small tribu- taries. The area has bottomland forest with wet prairie, sloughs, oxbows, and marshes. The bottomlands are the last strongholds of the eastern deciduous forest in Illinois. The immense size of the trees (some are over 130 feet tall and six feet in diameter) and diversity- of species are remarkable features of the woods. Several state tree champions are pre- sent in Beall Woods Nature Preserve. • Most of the Southern Till Plain RRA lies within the Little Wabash River watershed, but the western arm comprising 1 2% of the area lies in the Kaskaskia River watershed. With 914 square miles, the Southern Till Plain is the second largest RRA. In presettlement times, the region was characterized by rolling prairies between broad woodlands following stream corridors. Today the area is largely agricultural. Nevertheless, a SO-mile stretch of the Little Wabash is a Biologically Significant Stream and almost one-fifth of the area is wooded. The Little Wabash is tlje smallest of the 10 watersheds. Table 45. Watershed Land Cover Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest 259,737 10.8% (6) 6.3% (8) Grassland 456,555 18.9% (4) 7.1% (8) Non-forested wetland 9,949 0.4% 9) 2.8% (9) Bottomland forest 90,652 3.8% (2) 10.4% (4) Water 15,851 0.7% (9) 3.2% (9) I'rban/liiiilt-up 3 1 ,979 1.3% (10) 1.7% (10) Cropland 1,547,458 64.2% (8) 7.2% (10) Total acreage 2,412,183 100.0% 6.7% (10) * The watershed's percentage of the land cover tyipe statewide, e.g., 6.3% of the state's upland fotvsts. Note: the watershed rank (Ist-lOth) is shown in parentheses 96 Critical Trends in Illinois Ecosystems H CTAP - INHS River Sites © RiverWatch Sites The Little Wabash watershed scored poorly according to every biological indicator con- structed with RiverWatch data. GALLATIN Figure 58. Monitoring Sites ECOSYSTEM MONITORING Because CTAP biologists have sampled only three sites in the Little Wabash watershed, no definitive statement can be made about the quality' of its streams. Of the three sites, Horse Creek near Dix was the best.WliUe it had a somewhat lower EFT taxa richness, its HBl score was very good and its fish richness and habitat quality were extremely high. Bonpas Creek, a large sandy stream near West Salem in Wabash Count)', had low habitat quality due to tremendous sand deposition, channelization, frequent bank failures, and frequent flooding. RiverWatch sampling was low also; only 20 samples were collected at seven sites on seven streams. The Little Wabash watershed scored poorly according to every biological indicator constructed with RiverWatch data.The watershed had the worst MBI among the 10 Illinois watersheds and was ninth or tenth in the other three indicators. Midge larvae, bloodworms, and h>drops)chid caddisfly larvae were the most common taxa collected. No trends in MBI or other indices are evident. Table 46. Watershed Indicator Scorecard Indicator Watershed Value Statewide Value Watershed Ranking Macroirirertebmtes HBI 4.6 5 2 2 MBI 6.6 5.^ 10 EPT ricliness -.0 -I 5 EPT taxa (RXXO 1.9 2.6 9 Taxa richness ^■^ 8.9 10 Taxa dominance 82.7% 80.4% 9 Fish Native fisli 16.5 13.6 2 Darter richness 2.5 1.9 3 Exotic species 0.0 0.2 1 Habitat Habitat score 104.0 88.6 7 Table 47. .MBI Values Statistic 19';5 1996 199~ 1998 1999 Ch-erall Average Slaiul.irtI dc\iatioii Miiiinium Maxinuim Number of sites -— 6.11 ^.42 6.10 5.60 6.61 2.21 0"2 149 ().53 0.24 1.45 5 l,-\ 5,61 5.96 5.42 5. 28 5.1.^ 10.^,^ 662 895 6."1 5 ,S4 10..^,^ 4 2 .^ 4 4 r * Only saniples with at least 25 organisms were included in Ihe anahsis. Big Miidd)', Saline and Cache Rivers Watershed 97 CHAPTER THIRTEEN Big Muddy, Saline and Cache Rivers Watershed Tliis watershed, featuring the Shawnee National Forest and the Cache River wetlands in southern Illinois, is generally considered to be among the state's richest ecological regions. It has the most acreage and the largest percent- age of land devoted to upland and bottomland forest and surface water, and it has the second-highest acreage and percentage of land in grassland and non-forested wetland. Conversely, it also has some of the small est acreage and percentage of land in cropland and urban uses. (See page 112 for a color map of the watershed's land cover.) Five Resource Rich Areas have been identified in this watershed — the Middle Fork of the Big Muddy, Illinois Ozarks, Cache River, Shawnee Hills and Cretaceous Hills. • The Middle Fork of the Big Muddy is a small, single watershed site covering 180 square miles. The significant natural features are the large tracts of forest located along the river. • Covering 729 square miles, the Illinois Ozarks is one of the richest, most biologically diverse areas of the state. Many species found here are rare and limited in distribution to this area of the state. This RRA encompasses the Mississippi River bottomlands, Ozark plateau, and unglaciated hill country. The Illinois Ozarks RRA shares a boundary with the Cache River RRA. • The Cache River RRA is located at the southern tip of Illinois; it covers 693 square miles. The upper reach flows through the hills of the Ozark plateau: the lower Cache flows through flatter coastal plains where drainage is slow and wet- lands become more abundant. Unique features include bald cypress- tupelo gum swamps and several species associated with the southern U.S. The Shawnee Hills RRA, covering 745 square miles, is a scenic wooded area in an unglaciated part of the state. An escarpment of sandstone nms east to west in this area. Bluffs, rugged hills, deep ravines, and clear streams support distinctive flora and fauna. Table 48. Watershed Ixtncl Cover Land Cover Acres Percent of Watershed Statewide Percentage* Upland forest Grassland Non-forested wetland Bottomland forest Water UrbanA)uilt-up Cropland Total acreage 991,770 924,376 50,302 227,037 101,734 84,037 1,350,312 3,729,571 26.6% (1) 24.8% (2) 1.4% (2) 6.1% (1) 2.7% (1) 2.3% (8) 36.2% (9) 00.0% 24.0% (1) 14.4% (2) 14.2% (2) 25.9% (1) 20.3% (1) 4.5% (7) 6.3% (8) 10.0% (5) This u'litcrsheil is generally considered to be among the state's richest ecolofiical re^^ions. * The ualersheil's /h'IiciiIi- iiflhf liiiiil coivr ly/ic sltiU'ifMc. en.. J-1% oj Ihc sliite's iifiliind /nn'st.i an' loailcd in Ihis iitilersbed i\(>te: the wtilersheil rtiiik ( Isl-IOIh) is shoiiii in /uiivnlheses. 98 Critical Trends in Illinois Ecosystems The Cretaceous Hills RRA, encompassing 137 square miles, is characterized by rolling hills of sand, gravel and clay and bottomlands along the Ohio River. Acidic seeps, which support some of the most interesting natural communi- ties in the state, are found in this area. richness was lower than expected. This was proba- bl)' due to the site being sampled later than usual for the region, with many species entering the egg stage of their life C) cle. The worst site was Mud Creek near Unionville, which had low EPT and habitat quality. ECOSYSTEM MONITOREVG The Cache River basin contains some of the most pristine streams in Illinois, but many streams in the Big Muddy and Saline river basins are heavily degraded because the natural riparian corridor has been denuded, and streams have been channelized and polluted with nutrients from row crop agriculture. From 1997 through 1999 CTAP biolo- gists sampled eight randomly chosen streams. They found that, overall, the watershed scored below average for EPT richness and HBI score. It scored slightly above average for total native fish and for habitat quality. The site with the best habitat condition was an unnamed tributary of Lusk Creek near Golconda. Although it had a very good HBI score, EPT taxa Table 49- Watershed Indicator Scorecard H CTAP -INHS Rivet Sites i..ri RlverWatch Sites A ForesiWalch Sites Indicator Watershed Value Statewide Value Watershed Ranking Macfoim 'ertebrates HBI 5.6 5.2 9 MBI 5.2 5." 1 EPT richness 6.-1 "1 - EPT taxa (RVtO 3.3 2.6 3 Taxa richness 9.4 8.9 3 Taxa dominance 77.2% 80.4% I Fish Native fish 16.0 13.6 3 Darter richness 1.8 1.9 5 Exotic species 0.3 0.2 6 Habitat Habitat score 94.0 88.6 5 Figure 59. Monitoring sites Between 1995 and 1999 RiverWatch volunteers collected 208 macroinvertebrate samples at ~9 sites along 68 streams. Most of the streams are located in the southern half of the watershed, either in the Cache River basin or within or near the Sha^^•nee National Forest. Very few of the monitored streams flow througli the heavily row-cropped ai^eas of the Big Mudd}' or Saline river basins. RiverWatch biological indicators generally rein- force the area's reputation as home to some of Illinois' finest ecosystems. Tlie watershed ranked first among the ten watersheds in .MBI and third in the number of EPT taxa. tA\'o proxies for the le\el of organic poUutiiin. Sowbugs, midges, and scuds were the three most common taxa: these species are common throughout the state ;uid have low to medium tolerance for pollution. Tlie watershed also ranked best in taxa dominance, a useful measure of species diversity. Overall, the indicators suggest that the Big Muddy/Salinc/Cache watershed — at least the southern portion — is among Illinois' best, rivaled only b\ the Spoon Ri\cr watershed. The average MBI declined fixim 6.2 to S.O between I99S and 199^). indicating imjiroved Big Muddy, Saline and Cache Rivers Watershed 99 stream quality (Table 50). However, the decline is not statistically significant. In addition, changes in several other indicators (including taxa richness and taxa dominance) suggest degradation, though these changes are also statistically insignificant. It will take more years of data before trends can be assessed with confidence. Table 50. MBI Values Table 51. Tree Species with the Highest Importance Values Statistic 1995 1996 1997 1998 1999 Overall Average Standard deviation Minimum Maximimi Number of sites 6.19 S.S 5.35 4.88 5.01 5.22 1.59 1.2.-S 1..-S.3 0.79 0.70 1.10 4.63 3.44 3.19 2.09 304 2.09 9.82 9.52 9.85 6.00 6.61 9.85 14 29 .35 48 48 174 * Only samples with til letisl 25 oriiiiiiisnis were hicliideil in the analysis. ForestWatch volunteers monitored 13 forest sites in the fall of 1998. Twelve were upland forests (nine oak-hickor)-, two tulip, one beech-maple) and one was an ash-cotton wood bottomland forest .Tree species ricliness ranged from seven to 17 species, with an average of 1 3 tree species per site, slightly above the statewide average of 1 1 .8 species per site. The site with only seven species was a beech- maple upland with a relatively low tree abundance of 62 trees in a monitoring area of 1500 vrr (the statewide average w as 1 1 1 trees) Forty-nniL ull i.i.\.i ueri. ivluilIccI hi the water- shed, the most in the state (75 taxa were reported statewide). This is not surprising since souliiern Illinois contains species found in both northern and southern latitudes. In general, the trees that weiv most abundant also had the largesi ba.sal areas and highest importance values (Table 5 1 ). Importance Value Species % of total trees counted (n= 1,448) % of total ba.sal area (20.9m-/ha) 33.8 Hickory 16",, 20% 28.3 White oak 8% 20% 16.3 Red oak 5'!'.', 11% 15.7 Sugar maple 10% 5'.',, 13.8 Tulip tree 4% 8% 10.7 Ash 8% 6% 9,1 Flowering dogwood 6% 1% 7.7 Winged elm 5% 2% 6.9 Southern red oak 2% 6% 5.9 American beech 2'!',', .^% Only one site showed clear signs of maple take- over (Fig. 60), with the tliree smallest size classes dominated by sugar maples. Maple takeover is not a factor, however, in most forests in the watershed. S 300 1 o 250 ■ .2 200- m 150 • S'lOO- g 50- : 0^ 1 1 J^ DOak ■ Hickory ■ Sugar maple 1 — b <5' 5.0-10 10.1-20 20.1-30 Tree diameter, centimeters 30.1-40 >40 Figure 60. Maple takeover in an oak-hickory forest There were no signs of gypsy moths at any site, but about half of the flowering dogwood trees at one site showed signs of dt)gwood anthracnose. Because flowering dogwoods are relaliveh abun- dant in the watershed and anthracnose has been found elsewhere, it is likely that other forests in the watershed have the di.sease. Future monitoring will provide more information on the extent of dogwood anthracnose. This watershed had the fewest ntimber of invasive shrubs and \ines recorded dtiring fail mon- itoring — only 13% of the 53 i .shrubs and \ines recorded. Multiflora rose was the only non-nalive 100 Critical Trends in Illinois Ecosystems ^^^HH The area is home to unique and extensive complex natural commu- nities that have earned state, federal, and international recognition for their biological significance. shrub recorded and Japanese honeysuckle the only non-native vine. Spring monitoring, at five sites, also recorded few invasive species among ground cover plants. Ground ivy, a non-native invasive species, was recorded at one site. Another site had two disturbance-sensitive plants — bleeding hearts and doll's eyes — while two other sites had one distur- bance-sensitive plant, the Virginia spiderwort. ■ Non-invasive vines 1 1 Japanese \ honeysuckle □ Statewide ■ Big Muddy Multiflora rose 1 ■ Honeysuckle Buckthorn Cranberry 1 1 200 400 600 800 1000 Stems per tiectare Figure 61. Number of invasive and non-invasive shrub and vine stems REGIONAL ASSESSMENTS One regional assessment has been conducted in this watershed — for the Cache River basin. Cache River Basin The Cache River originates in Union County and runs 110 miles before it empties into the Ohio River The basin drains nearly the entire southern tip of Illinois and includes nineteen water- sheds covering approxi- mately 8.^S square miles. Sixty-four percent of the land is either cropland or pasture; statewide, 77% of the land is agri- cultural. Twenty- percent of the land is owned b)- state or federal agencies, primarily the U.S. Department of Agriculture (Shawnee National Forest) and the U.S. Department of the Interior (Cypress Clreek National Wildlife Refuge). The area still has a third of the land in forest, two and a half times higher than the state average. and it has a relati\el\' large percentage of the state's unique habitats. Although it makes up only 1.5% of the land area of Illinois, it contains 23% of the state s remaining high quality barrens, 11.5% of the high quality- floodplain forest, 91% of the state's high qualit}^ swamp and 42% of the shrub swamp.. \lso. though caves are scarce in the rest of Illinois, there are 43 caves known here. Given its relatively large amount of forest, including significant bottomland forest, the area is home to unique and extensi\e complex natural commimities that have earned state, federal, and international recognition for their biological signifi- cance. For example: • the United Nations Educational, Scientific, and Cultural Organization added the Cache River and Cypress Creek wetlands to its list of 15 "Wetlands of International Importance" in the United States because of their crucial role in sustaining waterfowl and shorebirds that use the Mississippi fl^-way: • the National Park Ser\'ice designated three areas of the Cache River basin as National Natural Landmarks because they represent nationally significant tvpes of vegetation and habitat; • most of the area (443.616 acres) has been designated a state Resource Rich Area; • 52 miles of Biologically Significant streams are recognized including segments of the Cache River Limekiln Slough, Horseshoe Uike. Lake Creek, and the Ohio River E FG ■ A Cropland (31.6%) ■ B Grassland (31. S'o) n C Upland forest (26.4'>o) n D Bottomland forest (7.0%) D E Urban/built-up (1.6%) ■ F Water (1.4%) ■ G Non-forested wetlands (0.5%) Figure 62. Cache Kircr basin hind cover Big Muddy, Saline and Caclic Rivers Watershed 101 Plant and animal life Diversity in habitat leads to a diverse flora and fauna. For example, the C^ache River bottomlands support the greatest diversity of tree species of any bottomland stream system in Illinois. Consequently, the area is home to 128 native bird species while another 1 29 migrate to the area. Basin acreage - 534,786.3 State land* - 24,773 acres Federal land - 34,775 acres Total natural areas - 19,074 acres High quality natural areas - 3,200 acres Nature preserves - 3,465.6 acres * Does not iiiciiule natural areas or nature preserves that may be state owned. With so much rare habitat, it is no surprise that the area also shelters man)' rare creatures — 104 species whose sur\'ival in Illinois is considered endangered or threatened, and seven species rec- ognized by federal authorities as endangered or threatened throughout the U.S. Among the man)' unique species that live in the area: • river otters — they persisted in the Cache River basin when they were disappearing from the rest of the state (they have since been rein- troduced in several areas ); • bald eagles — 20 to 50 winter in the cypresses lining Horseshoe Lake; • bobcats — with a home range as much as 3. 2 5 square miles, the Shawnee Hills is one of three places in Illinois that offers this animal enough space to roam; • the green treefrog, bird-voiced tree frog, cot- tonmouth and mole salamander — they all reach the northern limits of their distribution here and are restricted to the cypress-bulton- bush s"wamps and adjacent watersheds. Local economy and outdoor recreation The area is uniquely rural. Toda)' the population is about the same as it was in 1870 and |'>opulati()n density is only one-fifth iIku oI the statewide average. The slow-growing population ma\ he traced to a slow-growing local economy. In recent years, the local econoni) grew less than one-hall as much as the state overall. The five main counties in the basin — Union, Massac, Johnson, Alexander and Pulaski — ranked among the 1 5 poorest counties in Illinois in 1990. Contributing to the local economy are numer- ous outdoor recreational opportunities. The area attracts many anglers and hunters, including many from Kentucky, Indiana, and Missouri, and many people visit the three state parks for activities such as sightseeing, hiking, cross-country skiing, and picnicking. In 1994, more than 2.6 million people visited the area's state parks and conser\'ation and natural areas. The parks generated $14.9 million in economic output, created about 396 jobs and increased personal income by more than $8.46 million. Threats Logging, water draining, and conversion to agricul- tural uses have lead to a considerable change since pre-settlement times. Approximately 80% of the area was densely forested when settlers arrived; today only a third of the area is forested. Ver)' little of the swamps and floodplain forests remain in pre- settlement condition.These physical changes to the landscape have had a profound ecological effect. Fragmentation - Fragmentation renders habitats too small to supply a sufficient food supply, to protect animals from predators, or to accommodate genetically varied breeding species. For example, small isolated tracts of forest had 40% fewer bird species than c o m p a r a b 1 y - s i z e d woods along Approximately 80% of the area was (tensely forested irhett settlers arrived; today only a third of the aiva is forested. 102 Critical Trends in Illinois Ecosystems The cypress- tupelo forest and the associated species of the swamps and sloughs are found only in the basin and are totally dependent upon the natural hydrologic cycle of the Cache River the Cache corridor. Nests of forest-dwellers in the basin, such as the yellow-billed cuckoo and indigo bunting, suffer more than 60% losses to predators. Losses are lower in the larger wooded tracts. Non-native species - Many of the plants that grow in the basin were introduced to the area, although the Cache River basin does not suffer infestations as severe as other parts of Illinois. Autumn olive is a significant problem throughout the area, and in the Cache River Natural Area in particular Black locust, planted to enrich depleted soils and to provide firewood, is a pest in such areas as the Halesia Nature Preserve. Altering water tlow - No change made in the past 190 years has affected the ecosystem more drastically than the reordering of the presettlement hydrology undertaken to cure the areas chronic flooding. These alterations speed the flow of water from where it falls into the nearest stream channel. Rushing the water downstream has caused massive bank erosion and gullying in the Upper Cache River channel and led to excessive sedimentation and channel aggregation in the Lower Cache River Natural Area. The continued gully formation and deepening of stream channels drains wetlands (e.g.. Bird Spring Pond, Heron Pond), whose eleva- tion becomes significantly higher than the stream channel because of channel bed scour Draining wetlands takes away the natural water control func- tions they provide, such as slowing moving water and moderating the extremes of flood and drought. It also diminishes habitat for migrating geese, bald eagles, and other waterfowl. Sedimentation -The reduced flow of the Lower Cache River area has caused most of the sediment from tributaries draining into it to deposit near the mouth of the tributary streams and within the Lower Cache. This has reduced the depth of water within the Lower Cache and degraded the aquatic and plant habitat within the area. The c>press- tupelo forest and the associated species of the swamps and sloughs are found only in the basin and are totally dependent upon the natural hydrologic cycle of the Cache River. This unique vegetation will continue to be threatened unless some favorable hjdrologic conditions are recreated in the basin. Diminished water qualiU" - Nearly all Cache basin stream segments monitored for water qualir\- by the Illinois Environment Protection Agenc\' were rated as "partial support/minor impairment" (water qualit)' has been impaired to a minor degree). Exceptions include all of Lick Creek which received the highest rating of "full support"' and a segment of the upper Cache that was rated as partial support/moderate impairment. Reasons for less than full support ratings include siltation and turbiditv^ from agricultural runoff and erosion in the Lipper Cache, and siltation, turbidit)\ channeliza- tion, and sedimentation in the Lower Cache. Opportunities Given the many unique natural communities and plant and animal species in the Cache River area, there are many opportmiities to preserve and enliance natural resources. For example, preser\-ing and restoring large habitat areas will prevent further habitat fragmentation. Larger tracts of forest and wetland would pnnide ior a greater number of bird species and pro\ide habitat for the state-threatened river otter, which requires large tracts of habitat. Improving hydrologic conditions — reducing bank erosion, entrenchment, and gulhing in the I'pper Cache and sedimentation and channel aggre- gation in the Lower Cache — will in turn improve the water qiialin- of streams and wetlands, prevent further loss of wetlands, and preserve habitat for ti.sh, waterfowl, and other animals. Watershed Land Cover Maps 103 Figure 63. Rock River Watershed i^T^nd^^-T^ k-f -f.. >! ■/ * C i,,ilca,i ;t' i'ivLl>.i,i Scale 1:1,100,000 liircsl- Dcciduous.c'loscd caiiopy l-i)resi- Deciduous.open canopy f-oiL'sl- Coniferous Wetland- Shallow marsh Wetland- Deep marsh Wclland- Swamp [ Wetland- Forested I Wetland- Shallow open water I Open water deeper than 2ni Urban- High density Urban- Medium high density Urban- Medium density I I Urban- Low density ^^1 Urban- Grassland I . I Ag- Row crops 1^ I Ag- Small grains ^^1 Ag- Rural grassland ^^^1 Ag- Orchards and nurseries ^^1 Barren and exposed land 301 5a 104 Critical Trends in Illinois Ecosystems Figure 64. Fox and Des Plaines Rivers Watershed Forest- Deciduous.closed canopy Forest- Deciduous.open Ciuiopy Forest- Coniferous I Wetland- Shallow marsh I Wetland- Deep marsh I Wetland- Swamp I Wctkuid- Forested I Wetland- Shallow oix'n water I Open water deeper than 2m Urban- High density Urban- Medium high density Urban- Medium density I Urban- Low density I Urban- GrassUmd I Ag- Row citips 1 Ag- Small grains I Ag- Rural grassland I Ag- Oa-h;mls and nurseries I BaiTcn and exposed land Scale 1:600.000 I Watershed Land Cover Maps 105 Figure 65. Kankakee, Vermilion and Mackinaw Rivers Watershed Scale 1:1,100.000 Forest- Deciduous.closed canopy I Forest- Dcciduous.opcn cunopy I Forest- Coniferous I Wetland- Shallow marsh I Wetland- [X-ep marsh I Wetland- Swamp I Wetland- Forested I Wetland- Shallow open water I Open water deeper than 2ni Urban- High density Urban- Medium high density Urban- Medium density Urban- Low density Urban- Grd.ssland I Ag- Row crops I Ag- Small grains I Ag- Rural grassland I Ag- Orchards and nurseries I Bairen and exposed land 106 Critical Trends in Illinois Ecosystems Figure 66. Spoon River Watershed 1^1 Forest- Dcciclimus.closcd canopy ^^1 Forest- Deciduous.open canopy ^^1 Forest- Coniferous I I Wcllanil- Shallow niai'sh J Wetlanil- Deep maisli Wellaml- Swamp Wcllaiid- Foivsted Wetland- Shallow open water Open water dec|X'r than 2ni Lh-tian- High density Urban- Medium liigli density Urban- Medium density Urban- Low density Urban- Grassland Ag- Row cixips Ag- SnnJI gi~ains Ag- Rural grassland Ag- Oivhards and nul^eries Barren and ex|X)sed land Scale 1:1,100,000 I 1~~ Watershed Land Cover Maps 107 Figure 67. Sangamon River Watershed Scale 1:1,100,000 son Forest- Deciduous.closed canopy Forest- Deciduous.opcn canopy Forest- Conitcrous Wetland- Shallow marsh Wetland- Deep marsh Wetland- Swamp Wetland- Forested Wetland- Shallow open water Open water dee|XT than 2m Urban- High density Urban- Medium high density Urban- Medium density Urban- Low density Urban- Grassland Ag- Row crops Ag- Small grains Ag- Rural grassland Ag- Orchards and niirscncs Barren and cxposetl land 108 Critical Trends in Illinois Ecosystems Figure 68. LaMoine River Watershed Forest- Deciduous.closed cuiiopy Forest- Deciduous.open canopy Forest- Coniferous Wetland- Shallow marsh Wetland- Deep marsh Wetland- Swamp Wetland- Forested Wetland- Shallow open water Open water deeper than 2ni Urban- High density Urban- Medium high density Urban- Medium density Urban- Low density Urban- Grasshind Ag- Row crops Ag- Small grains Ag- Rural grassland Ag- Orchards and nurseries Ban'en and exposed land Watershed Land (;over Maps Figure 69. Kaskaskia River Watershed I Forest- Decidut)us.cIosed cunopy Forest- Deciduous.open canopy I Forest- Coniferous I Wetland- Shallow marsh I Wetland- Deep marsh I Wetland- Swamp I Wetland- Forested I Wetland- Shallow open water I Open water deeper than 2m Scale 1:1.100,000 110 Critical Trends in Illinois Ecosystems Figure 70. Embarras and Vermilion Rivers Watershed I Forest- Deciduous.closed canopy I Forest- Deciduous.open canopy I Forest- Coniferous I Wetland- Shallow marsh I Wetland- Deep manih I Wclliuid- Swamp I Wetland- Forested I Wetland- Shallow open water I Open water deeper than 2m I Urban- High density I Urban- Medium high density I Urban- Medium density I Urban- Low density I Urban- Grassland j Ag- Row crops ] Ag- Small groins j Ag- Rural grassland j Ag- Orchards and nurseries Barren and exposed land Scale 1:1000000 Watershed Uind Cover Maps 111 Figure 71. I.illle Wabash River Watershed Purest- Dcciduous.closcd ciinopy Forest- Deciduous.open canopy Forest- Coniferous I Wetland- Shallow marsh Wetland- Deep marsh ^H Wetland- Swamp ^^1 Wetland- Forested [ J Wetland- Shallow open water ^^1 ( )|x;n water deeper than 2ni Lirhan- High density Urban- Meditiin high density Urban- Medium density Urban- Low density Urban- Grassland I Ag- Row crops I Ag- Small grains Ag- Rural grassland Ag- Orchards and nurseries Barren and exposed land 112 Critical Trends in Illinois Ecosystems Figure 72. Big Muddy, Saline and Cache Rivers Watershed Scale 1:1000000 a Mil Forest- Deciduous.closcd canopy Forest- Deciduoiis.opcn canopy ForesI- Coniferous Wetland- Shallow marsh Wetland- Deep marsh Wetland- Swamp Wetland- Forested Wetland- Shallow open water Open water deeper than 2m I Urban- High density I Urbiui- Medium high density ! I'rhan- Metliiim density 1 LIrhan- Low density I Urban- Grassland J Ag- Row crops Ag- Sm;ill grains ^^1 Ag- Rural grassland I* ''*^| Ag- Orchards and niiiNcries 1^1 Banvn and exposed Imid