The upper Green River watershed in Kentucky is known for an aquatic faunal community among the richest in the U.S., hosting 151 fish species and 73 mussel species, including nine listed as endangered. This basin has been the focus of a USDA Conservation Reserve Enhancement Program (CREP) designed to convert pasture and crop land to riparian buffer along the Green River and its tributaries, and has recently been expanded to include restoration of significant regions of karst drainages through native grass and forb plantings around sinkholes as well. A multifaceted sampling program has been undertaken to assess impacts of the riparian corridor restoration, including measurements of water quality, aquatic biota, habitat parameters, riverbank erosion, vegetation characteristics of restored grasslands, avian use of the grasslands and forested riparian corridor, and, using a geographical information system (GIS) approach, landuse assessments and watershed characteristics at multiple scales.
Results/Conclusions
Some of the water quality parameters related most strongly to current land use patterns are total suspended solids, turbidity, specific conductance, triazine concentrations, and E. coli; precipitation was an important cofactor. Severe bank erosion was more frequent on banks lacking a forested riparian buffer, and less frequent in a region dominated by karst drainage. Grassland restoration areas exhibited increased plant species richness and structural diversity. Responses of riparian birds to surrounding landuse at multiple scales have also been analyzed. Over 5,000 Carolina wren calls were detected using bioacoustic analysis on recordings made in the riparian zone of the Green River corridor. Higher densities of wintering song sparrows and swamp sparrows were found in CREP fields than in fescue fields. The responses of biotic and abiotic system components to restorations of agricultural land to riparian buffer and native grasslands has been complex and highly interconnected.
