HR: 09:45h
AN: NB51C-06 INVITED     [Abstracts]
TI: Effects of Fragmentation on Macroinvertebrate Community Composition in Vernal Pools
AU: * Breneman, D
EM: dbrenema@nrri.umn.edu
AF: University of Minnesota Duluth, Natural Resources Research Institute, 5013 Miller Trunk Hwy, Duluth, MN 55811 United States
AU: Johnson, L
EM: ljohnson@nrri.umn.edu
AF: University of Minnesota Duluth, Natural Resources Research Institute, 5013 Miller Trunk Hwy, Duluth, MN 55811 United States
AU: Johnson, C
EM: catherinejohnson@fs.fed .us
AF: Monongahela National Forest, 200 Sycamore St., Elkins, WV 26241 United States
AB: The dynamic nature of vernal pools attracts aquatic communities highly adapted to hydrologic disturbance, but these systems remain susceptible to landscape alterations. We examined the effects of forest fragmentation on invertebrate community structure in temporary pools in northern Minnesota. D-frame nets were used to sample invertebrates in 18 fragmented and 20 unfragmented pools in the early spring and summer during high and low water levels. Twenty metrics based on invertebrate characteristics were analyzed using a mANOVA to examine treatment and seasonal interactions. A majority of the variance (50 percent) was explained by factors related to treatment, and Canonical Correspondence Analysis (CCA) results showed weak relationships between community structure and habitat variables. Total taxa increased slightly between early and late sampling for both treatments, but the fragmented pools contained significantly more taxa and a higher overall abundance than in the unfragmented pools. These differences may be attributed to hydroperiod, as fragmented pools dried up with less frequency, and experienced less water volume loss than the unfragmented pools. Although seasonal changes in vernal pool communities occurred, aquatic insects showed a greater response to local habitat conditions. Landscape alterations such as forest fragmentation can significantly alter temporary pool invertebrate community composition.
DE: 1871 Surface water quality
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly