This project produced a series of attributed GIS feature classes that describe nested classification units consisting of Ecological Drainage Units and Aquatic Ecological Systems that can be used for conservation and management planning for stream systems at a variety of landscape scales. Valley Segment Types were also developed for the 1:100,000 scale GIS that was available when the project was started but have not yet been redeveloped for the finer scale system (1:24,000).
We also examined existing Illinois Natural Areas Inventory (INAI) Natural Community Types (NCT), and Subtypes, associated with streams and identified areas that meet the physical descriptions of these NCTs based on stream size and gradient. We discuss the identification of natural features in terrestrial and stream systems within the initial development of the INAI and how this lead to differences in their evaluation and separation into different Categories (Category I: High Quality Natural Communities; Category VII: Outstanding Aquatic Features). An approach for defining and evaluating natural features for stream systems that is more similar to that used for terrestrial NCTs is presented.
Information from recent and historical surveys of fish, mussels, and other invertebrate taxa was assembled for use in identifying potential Illinois Natural Areas Inventory (INAI) sites using existing criteria for streams. We identified stream reaches that contained current element of occurrence records for Illinois Endangered and Threatened fish and mussels including those that were not currently listed on the INAI that may qualify as Category II sites (Specific Suitable Habitat of Endangered and Threatened Species) and give recommendations for their further evaluation. These data were also used to identify stream reaches that may qualify for the INAI as Category VI (Unusual Concentration of Flora and Fauna). Additional guidance is provided for implementation of existing criteria that use mussel species richness, the mussel classification index, and the fish index of biotic integrity as criteria for qualifying as Category VI INAI sites.Illinois Department of Natural Resources, Division of Natural HeritageIllinois Department of Natural Resources, State Wildlife Initiative Grants Program T-75-R-001unpublishednot peer reviewedOpe
