Small Mammal Communities In Riparian And Upland Habitats on The Upper Coastal Plain Of Virginia

We compared small mammal communities between riparian (stream corridor) and nearby upland habitats in a hardwood forest ecosystem on Fort A.P. Hill, Caroline County, Virginia. We used a combination of small-scale drift fence/pitfall trap arrays and snap traps to capture small mammals during April October 1998, with an additional winter sample in January 1999. We captured seven small mammal species at 14 sites (7 pairs). Numbers of species were not significantly different between habitat types. Bray-Curtis polar ordinations showed that plant and small mammal community compositions were similar in upland sites and that these communities were most varied in riparian sites. Riparian sites supported wetland and moist soil obligate plants that made this habitat type distinct from upland sites. Small mammal communities were dominated by Peromyscus leucopus and Blarina brevicauda. Numbers of individual small mammals captured were higher in riparian sites than in upland sites. Mean number of captures per trap night averaged 2.6 in riparian sites and 1.4 in upland sites but the difference was not statistically significant. Numbers of rodent captures were significantly higher in both habitat types than captures for insectivores. Hardwood habitats in riparian and upland systems support diverse small mammal communities in the upper Coastal Plain of Virginia. Because small mammals use both habitat types extensively, composition of contiguous upland habitats should be considered in studies of tl1ese animals in riparian ecosystems. INTRODUCTION Focus on riparian ecology and management has intensified recently because of local, state, and federal mandates to protect water quality and biodiversity (see reviews in Veny et al., 2000). For example, species and their habitats are required to be protected ( or at least managed for their protection) under such federal mandates as tl1e National Forest Management Act and Section 404 oftl1e Clean Water Act. Most oftl1e research that has been conducted on tl1e ecology of small mammals in riparian ecosystems has occurred in tl1e Midwest (Geier and Best, 1980) and tl1e Pacific Northwest (e.g., Doyle, 1990~ McComb et al., 1993). Comparatively little research has been conducted in eastern North America. Two studies in southeastern North America Correspondence address of ASB: Department of Biology, Old Dominion University, Norfolk, Virginia 23529. Correspondence address of JCM: Department of Biology, University of Richmond, Richmond, Virginia 23173. ,., ,,