Small mammals: pests or vital components of the ecosystem

摘要: —Small mammals regarded as "pests" should not be viewed separately from other components in the ecosystem. Small have significant influences on vegetation and soils, exert predatory pressure animals, provide food for predators. Future management efforts include consideration of these diverse influences. Careful evaluation role small their relationships with environment is necessary to fully appreciate impact control programs Rather, must terms interrelationships components. Alteration mammal communities through influence ultimately whole system. may grouped those effects (1) vegetation, (2) (3) animals. Vegetative primary productivity, plant species composition, decomposition rates materials. both physical chemical properties soils. prey insects occasionally mammals, a base carnivores, modify environments such way habitat INFLUENCES ON VEGETATION Researchers proposed various ways which interact communities. The main interactions can categorized relating stature reproduction, Paper presented at 8th Wildlife Damage Control Workshop, April 28-30, 1987, Rapid City, South-Dakota. Sieg Biologist Rocky Mountain Forest Range Experiment Station, South Dakota, cooperation Dakota School Mines Technology. Station's headquarters Fort Collins, Colorado State University. Primary Production herbivores consume much 60% (Migula et al. 1970) 80% (Taylor Loftfield 1942) total annual production. They localized, large-scale impacts productivity during population explosions. However, effect direct consumption plants by evaluated what portion production actually available animal. Estimates herbage ranged <1% northern shortgrass midgrass sites 20% desert grasslands (French 1976). Harris (1971) estimated that 0.17-5.01% net was transferred rodent trophic level. Hayward Phillipson (1979) concluded or negligible most systems. Light grazing stimulate For example, moderate voles (Microtus oeconumus M. middendorffit) increased two stimulating new shoot growth (Smirnov Tokmakova 1971, 1972). Regrowth rye grass (Lolium perenne) had been grazed hispid cotton rats (Sigmodon hispidus) faster than regrowth mechanically clipped (Howe 1982). authors speculated either biochemical agent saliva specific manner tissue removal stimulated