THE AUTHORS 



DEAN E. MEDIN is a research wildlife biologist with 

 the Intermountain Research Station at the Forestry 

 Sciences Lakwratory in Boise, ID. He earned a B.S. 

 degree in forest management from Iowa State Univer- 

 sity in 1957, and from Colorado State University he 

 earned an M.S. degree in wildlife management in 1959 

 and a Ph.D. degree in range ecosystems in 1976. His 

 research has included studies in mule deer ecology, 

 big-game range improvement, mule deer population 

 modeling, and nongame bird and small mammal 

 ecology and habitat management. 



WARREN P. CLARY is Project Leader of the 

 Intermountain Research Station's Riparian-Stream 

 Ecology and Management research work unit at Boise, 

 ID. He received a B.S. degree in agriculture from the 

 University of Nebraska and an M.S. degree in range 

 management and a Ph.D. degree in botany (plant 

 ecology) from Colorado State University. He joined 

 the Forest Sen/ice in 1960 and has conducted re- 

 search on forested and nonforested rangelands in 

 Arizona, Louisiana, Utah, Idaho, Oregon, and Nevada. 



ACKNOWLEDGMENTS 



We gratefully acknowledge the field or office assis- 

 tance of John W. Kinney, Sherri A. Brown, Justine L. 

 Wirch, Kevin Tom, and Patrick V. Turner. Lyie A. 



Lewis, Caryl Elzinga, Loren D. Anderson, and Gtoria 

 Romero provided unpublished information about the 

 study area. 



RESEARCH SUMMARY 



We compared snfiall mammal populations and 

 community organization between a beaver pond 

 ecosystem dominated by wiltows (Salix spp.) and an 

 adjacent nonwillow riparian habitat on Summit Creek 

 in east-central Idaho. Populations were assessed by 

 removal trapping on 1 .7-ha grids in late summer of 

 1988 and 1989. Small mammal relative density was 

 3.06 times higher and standing crop biomass was 

 2.71 times higher in the beaver pond habitat than in 

 the adjacent nonponded habitat. There were no 

 pronounced differences between the two habitats in 

 small mammal species richness or species diversity. 

 Montane voles {Microtus montanus) and shrews 

 {Sorex spp.) were most abundant in the beaver pond 

 habitat, while the deer mouse {Peromyscus mani- 

 culatus) was the most commonly trapped small 

 mammal in the nonponded riparian area. Among four 

 foraging guilds represented on the study site, herbi- 

 vores and insectivores were numerically dominant in 

 the beaver pond habitat. The dense and structurally 

 more complex vegetation of the beaver pond ecosys- 

 tem apparently provided the food and cover resources 

 needed to support larger populations of small mammals. 



The use of trade or firm names in this publication is for reader information and does not 

 imply endorsement by the U.S. Department of Agriculture of any product or sen/ice. 



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