Monday, May 26, 2008 - 2:15 PM
76

(TALK WITHDRAWN BY AUTHOR) patterns of macroinvertebrate diversity and community structure across a gradient of river-floodplain connectivity

Bradley S. Williams, Department of Ecology and Evolutionary Biology, University of Kansas, 2041 Haworth Hall, 1200 Sunnyside Ave, Lawrence, KS 66045 and Reid Adams, Department of Biology, University of Central Arkansas, 201 Donaghey Ave. LSC 180, Conway, AR 72035.

 A limited number of studies have examined the effects of river-floodplain connectivity on macroinvertebrate diversity and community structure, and even fewer have utilized a multi-spatial scale approach.  This study assessed these effects by sampling macroinvertebrates within the vegetated shoreline of 18 riparian wetlands with different degrees of hydrologic connectivity to the Arkansas River. Analysis included core samples and habitat data taken from 6 backwaters contiguous with the main channel, 6 floodplain wetlands intermittently connected to the river by supra-bankfull flooding, and 6 floodplain wetlands isolated from the river by levees. Though there was no significant effect of connectivity on α diversity, overall β-1 and β-2 diversity was higher in intermittent and isolated floodplain wetlands than in backwaters. This indicated a greater degree of compositional dissimilarity among the wetlands comprising these regions. Non-metric multidimensional scaling and indicator species analysis revealed a number of taxa with strong associations with each wetland type and that macroinvertebrate community structure was influenced by connectivity. These patterns of diversity and community structure and the mosaic of habitats observed in the Arkansas River Floodplain are a product of dynamic hydrologic processes such as river-floodplain connectivity.


Web Page: Arkansas River, Beta Diversity, Wetlands

See more of Large River Ecology
See more of Contributed Sessions

See more of The Nabs 56th Annual Meeting (25-28 May, 2008)