Assembly and disassembly of mammal communities in a fragmented temperate rain forest

We capitalized on the anthropogenic, large-scale "experiment" of deforestation in the temperate rain forests of the Olympic Peninsula, Washington Stare, USA, to test whether mammalian-community structure is significantly influenced by anthropogenic transformation of this landscape (principal macrohabitats include continuous, old-growth forest; old-growth corridors; old-growth fragments; second-growth forest; and clearcuts). Species richness of all non-volant mammals was lowest in second-growth forests, while richness of the eight forest-dependent species was lowest in clearcuts. Species composition of mammalian communities differed significantly among the five principal macrohabitats, as did environmental characteristics recorded at each survey site. These differences indicate that both natural and anthropogenic processes have resulted in the nonrandom assembly of mammalian communities in this transformed, temperate rain forest landscape. The effects of deforestation are significant, interpretable (based to a large degree on changes in local habitat), and persistent given that the structure of mammalian communities from mature second-growth forests (up to 80 yr post-harvest) have not converged on those from native, old-growth forests.