Factors Influencing Structure of Headwater Stream Communities in the Cuyahoga Valley National Park, Northeast Ohio

Download or read book Factors Influencing Structure of Headwater Stream Communities in the Cuyahoga Valley National Park, Northeast Ohio written by Marie Ann Schrecengost and published by . This book was released on 2005 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Processes at various spatial and temporal scales are known to affect lotic systems and the organisms that inhabit those systems. Because processes within watersheds are interactive across spatial scales, it is important to examine these processes at multiple scales. Additionally, multiple taxa studies are necessary in ecology because each group of taxa has a very different life-history and may react differently to various processes. Studies involving multiple taxa groups have been limited by the taxonomic specialization of many ecologists. Recent studies have examined the effects of single-scale processes on one or two groups of taxa or multiple-scale processes on a single group of taxa. However, multi-scale and taxa research has been neglected. In this study, I examined the effects of hierarchical landscape properties on aquatic macroinvertebrate assemblages in four first and second order streams in the Cuyahoga Valley National Park. Processes at sub-basin, reach, and microhabitat scales were studied to determine their influence on the macroinvertebrate assemblages. Sampled biota, in addition to macroinvertebrates, included salamanders and fishes: these biota were assessed in their relationship to the same hierarchy of habitat properties. Processes at each of the scales I examined had influence in structuring each group of taxa. Macroinvertebrate families are influenced most strongly by processes at the microhabitat and reach scales. Sub-basin and reach scale properties influenced salamander assemblages, and fishes were influenced more strongly by factors relating to stream size (both sub-basin and microhabitat). Stream size factors are determined mostly by watershed area, but underlying geology and hydrology also playa role. The presence of fish had no detectable effect on macroinvertebrate structures and a negligible effect on salamander assemblages.