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Monday, May 26, 2008 - 4:45 PM
111
The effects of habitat heterogeneity on macroinvertebrate community stability and food web structure
Raven L. Lawson and Bryan L. Brown. Department of Forestry and Natural Resources, Clemson University, 261 Lehotsky Hall, Clemson, SC 29634-0317
Previous research suggests that community stability increases with habitat heterogeneity. The objective of this study was to determine if high substrate heterogeneity would increase stability among a local benthic macroinvertebrate community, due to increased refugia from predators. We manipulated substrate heterogeneity in twenty enclosures placed along a 300m reach of Six Mile Creek in the Clemson University Experimental Forest. We used an analysis of covariance design with crayfish (Cambarus bartonii) presence or absence as a fixed factor, and substrate heterogeneity as a continuous factor. Substrate heterogeneity ranged from plots of nearly homogeneous substrate composition to plots of extremely diverse substrate composition that included several different cobble sizes as well as sand, gravel, and CPOM. After an acclimation period of two weeks, we sampled the macroinvertebrate community weekly (for eight weeks) to track changes in community structure. We predicted that stability in enclosures containing crayfish would increase with substrate heterogeneity while there would be no change in stability with habitat heterogeneity in enclosures without crayfish. In this paper, we discuss the effects of habitat heterogeneity and predator presence/absence on macroinvertebrate community stability and food web structure using community composition, and effects on algal and detrital resources.
Web Page: Habitat Heterogeniety, Macroinvertebrate Community Stability, Food-web Structure
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)
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See more of The Nabs 56th Annual Meeting (25-28 May, 2008)