FOREST FERTILIZATION WITH BIOSOLIDS - IMPACT ON SMALL MAMMAL POPULATION-DYNAMICS

This study was designed to measure the effects of a biosolids (sewage sludge) fertilization application on resident small mammal populations in young coastal coniferous forest near Maple Ridge, British Columbia , Canada. Populations of the deer mouse (Peromyscus maniculatus), Oreg on vole (Microtus oregoni), Townsend chipmunk (Eutamias townsendii), s hrews (Sorex spp.), and a few species caught occasionally, were sample d in replicated control and treatment study sites from May 1990 to Oct ober 1991. Sludge application occurred in November 1990. Them were no detectable differences in the abundance of deer mice, Oregon voles, an d chipmunks on treatment areas relative to controls after sludge appli cation. This was also the case for recruitment, survival, mean body we ight and species diversify. There was, however, a significant increase in the growth rate of juvenile deer mice on post-treatment sites. We conclude that then: was no apparent effect on population parameters at tributable to sludge treatment one year after application. Silvicultur al applications of biosolids likely have less impact on small mammal p opulations than other forestry practices such as harvesting and slashb urning.