Small mammals in oak woodlands in the Puget Trough, Washington.

Abstract

We surveyed the 22 largest sites dominated by Oregon white oaks on the Fort Lewis Military Reservation, Washington, to determine small-mammal community structure and population abundances. Study areas were in the Puget Trough physiographic province and western hemlock vegetation zone. Most oak communities were ecotonal between prairie and Douglas-fir forest. Small mammals were sampled at each site using paired lines of live traps for four nights, July and August 1999. In order of decreasing abundance, the deer mouse, vagrant shrew, Trowbridge's shrew, and creeping vole were the most abundant and widespread species. The dusky shrew and the southern red-backed vole were infrequently captured in oak ecotones but were abundant in nearby secondgrowth Douglas-fir forest. The relative influences of prairie versus Douglas-fir forest on oak ecotones determined understory plant composition and occurrences of small mammal species. The combination of abundant vagrant shrews and few dusky shrews in oak ecotones suggest that soil food webs and organic matter accumulation differed between oak ecotones and Douglas-fir forest.

Citation

Wilson, S.M.; Carey, A.B. 2001. Small mammals in oak woodlands in the Puget Trough, Washington. Northwest Science. 75(4): 342-349