Relative importance of Conservation Reserve Programs to mayfly, stonefly, and caddisfly species richness in the Kaskaskia River basin of Illinois

Conservation Reserve Program;EPT species richness;Kaskaskia River, Illinois

South, Eric James ; DeWalt ; Ralph E

关键词: Conservation Reserve Program;    EPT species richness;    Kaskaskia River, Illinois;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/90890/SOUTH-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The Conservation Reserve (CRP) and Conservation Reserve Enhancement Programs (CREP), funded by federal and state government, offer farmers financial incentives to take erosive agricultural lands out of production. Within these program landscapes, several best management practices, including riparian zone easements and restoration, are used along streams and wetlands to improve habitat for riparian and in-stream species (State of Illinois 2013). This thesis investigates the efficacy of CRP and CREP lands to support assemblages of three environmentally sensitive orders, Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) (EPT) in the Kaskaskia River basin, a heavily impacted, predominantly agricultural watershed in central and southern Illinois. A total of 10,522 EPT specimens were examined from 84 sites across the basin during May and June of 2013-2015. Seventy-six variables from geographic information system (GIS) and in-situ generated variables were used in an Akaike information criterion analysis (AICc) to construct a set of 13 best regression models accounting for variance in EPT basin richness. AICc importance values and hierarchical partitioning revealed five important variables associated with EPT richness: Link (number of first order tributaries), WT_Perm (soil permeability at the total catchment level), WT_Urban (urban land use at the total catchment level), Silt, and DO (dissolved oxygen). AICc showed that Link and WT_Perm have the highest importance value (1.00), followed by WT_Urban (0.99), and Silt (0.83). Individual percent contribution (% I) as determined by hierarchical partitioning placed DO third among these five variables. The amount of CRP/CREP land in the drainage ranked low in relative importance and % I contribution, suggesting that this mosaic of conservation practices may not contribute significantly to supporting highly diverse EPT assemblages.