Restoration of agricultural land to riparian buffer in the upper Green River watershed of Kentucky

The upper Green River watershed in Kentucky is known for an aquatic faunal community that is among the richest in the U.S., hosting 151 fish species and 73 mussel species, including nine listed as endangered. This basin has been targeted for a USDA Conservation Reserve Enhancement Program (CREP) to convert pasture and crop land to riparian buffer along the Green River and its tributaries, and has recently been expanded to include karst drainages via 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 a range of scales. Some of the water quality parameters related most strongly to current land use patterns are fecal coliform bacteria, total suspended solids, turbidity, specific conductance, and triazine concentrations; 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. Higher densities of wintering birds 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.