Land Use Riparian Vegetation And Stream Ecosystem Integrity In An Agricultural Watershed A Thesis Submitted In Partial Fulfillment For The Degree Of Master Of Science Natural Resources And Environment

Author : Heather Lyn Whitman
Publisher :
ISBN 13 :
Total Pages : 127 pages
Book Rating : 4.:/5 (945 download)

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Download or read book Effects of Adjacent Land-use Practices and Environmental Factors on Riparian Vegetation and Water Quality in the Sugar Creek Watershed, Northeastern Ohio written by Heather Lyn Whitman and published by . This book was released on 2009 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Riparian areas provide many critical ecosystem functions, including reducing nutrients and sediments from surface runoff, reducing erosion, and providing shade and organic matter to stream ecosystems. One watershed with highly disturbed riparian areas is the Sugar Creek watershed in northeastern Ohio, which was identified by the Ohio Environmental Protection Agency as one of the most degraded in the state. We examined how land-use influences water quality in the South Fork subwatershed of Sugar Creek. These analyses imply that urbanization is associated with total solids, turbidity, conductivity, and the concentration of phosphorus and ammonia. Wooded areas and buffer strips are inversely associated with agricultural land-uses, pH, and nitrate concentration levels. We suggest that restored riparian buffers can help improve water quality by reducing sediment and phosphorus loadings through reducing erosion, and can help alleviate nitrogen loadings via plant uptake. Additionally, understanding these relationships can help farmers and resource managers target specific subwatersheds that require restoration plans to improve overall water quality in the Sugar Creek watershed. To better understand the current condition of riparian areas in the Sugar Creek watershed, and the factors that influence their development, we examined the composition and structure of the ground-flora, sapling, and overstory layers of riparian areas of three subwatersheds of Sugar Creek with contrasting geology and land-use histories. We found that ground-flora species composition was significantly different among riparian areas adjacent to different land-uses in the Upper (P=0.0018) and South Fork (P=0.0450) subwatersheds. Few differences in ground-flora diversity were observed among riparian areas with different adjacent land-uses; however, riparian areas adjacent to grassed pastures had the highest species richness and Shannon Diversity Index in the South Fork subwatershed. We found that many highly invasive, non-native species were present in the ground-flora of riparian areas adjacent to lawns in the Upper subwatershed, grassed pastures in the North Fork subwatershed, and mixed row crop and grassed pastures in the South Fork subwatershed, suggesting that riparian areas adjacent to these land uses require active restoration. Additionally, the presence of these non-native invasive species, including Alliaria petiolata and Schedonorus phoenix, may make it difficult to successfully restore these riparian areas to a more natural condition. We observed few differences in the overstory composition of riparian areas, regardless of adjacent land-use in all three subwatersheds (P=0.3650). Results from ordination analyses supported this conclusion, as we observed strong relationships between individual overstory species, adjacent land-use, physiographic, and stream variables. Despite these similarities, we found significant differences in the overstory structure of riparian areas adjacent to different land-uses, including mean point-to-tree distance (P=0.0000), basal area (P=0.0150), and canopy openness (P=0.0070). Specifically, riparian areas adjacent to wooded land-uses had the most diverse canopy structure in terms of crown class of overstory trees, as well as the most saplings than any other land-use type. This suggests that the riparian areas adjacent to more wooded areas in the Sugar Creek watershed are more structurally complex than those areas adjacent to more frequently disturbed land-uses, such as lawns, pastures, and row crops.