Contents Notes |
Land use and cover patterns, such as forest vs. farmed lands (which in Northeast Ohio include both technological modern farms and traditional Amish properties), can greatly influence ecological functioning at multiple scales. Too often, alterations in land use have been made with little or no consideration of potential impacts on adjacent systems, including streams. The objective of this thesis was to evaluate influences of land cover on habitat for fish and other aquatic vertebrates within tributaries of the Grand River in Ashtabula, Trumbull, and Geauga Counties. I used Geographic Information System tools to delineate watersheds of 8 tributaries, and to determine percentages of forested, wetland, and farmland in each. I used a combination of land parcel search by common Amish surnames, in addition to ground trothing to differentiate Amish vs non-Amish properties. I conducted Qualitative Habitat Evaluation Indices (QHEI) at publicly assessable points on each stream, and also calculated stream gradient above assessment sites. I used Pearson Correlation and Principle Components Analysis (PCA) to investigate associations among land cover, stream gradient, and habitat quality variables. Watersheds closest to the Grand River were predominantly forest and wetlands. There was a distinct spatial separation between Amish and non-Amish farms, with Amish farms concentrated in uplands to the west of the Grand River Valley near the village of Middlefield. QHEI scores ranged from 47 (poor/fair) to 80 (excellent). In-stream factors such as sediment heterogeneity and riffle-pool development contributed the most to high QHEI scores. High Gradient streams also scored the highest in habitat quality. PCA also revealed these patterns in land cover, interestingly suggested that land cover was not strongly influencing stream habitat quality. Habitat assessment sites located substantial distances from farms, so perhaps the natural land cover in between may be sufficiently buffering impacts of human land uses. |