Succession Effects on Mammal and Inverterbrate Communities 26 Years After the 1988 huckleberry Mountain Fire

Abstract

Fires are an important and increasingly common driver of habitat structure in the intermountain West. Through an ongoing study of burned and adjacent unburned areas along the John D. Rockefeller, Jr. Memorial Parkway, we examine the long-term effects of the 1988 fire season on community assembly, succession, and ecological processes. We collected mark/recapture data on rodents, removal data for insectivorous mammals and invertebrates, and habitat measurements on four grids in 2014 and combined these results with previous survey data. In 2014, 4,800 trap nights yielded 13 species of small mammals, comprising 618 individuals. Macroarthropod abundance was higher on burned grids, but diversity was higher on unburned grids. In contrast, springtail (Collembola) diversity was higher on burned grids, but abundance was highest in unburned grids. Since the beginning of this long-term study, the total number of mammal species has increased across all sites, and relative abundance in burned areas has shifted from early successional species (Peromyscus maniculatus) to those more associated with old growth forests (such as Myodes gapperi). Other than in 1991, the burned grids have harbored more diverse small mammal communities than the unburned control grids. Significant, long-term differences in vegetation based upon burn history were observed, including different ground cover, less canopy cover, and more coarse woody debris in burned sites. This work provides a unique long-term picture of the interrelationships of small mammal and invertebrate communities and correlated habitat variables as these ecosystems undergo post-fire succession.