Small mammals influence and can even regulate the composition of plant communities in desert systems. However, increasing frequency of fire associated with the invasion of exotic grasses in deserts of the western United States alters small mammal communities. Shifts in small mammal communities have the potential to alter composition of plant communities and influence success of post-fire revegetation efforts. Our objective was to evaluate the interactive effects of fire and small mammals on survival of seedlings of common plant species in the Mojave and Great Basin Deserts. We used a randomized complete block design with four treatments (small mammals with fire, small mammals without fire, no small mammals with fire, and no small mammals without fire) and five replicates in each desert. Small mammals had a significant effect on survival of seedlings. Seedlings in plots without small mammals had 54% and 37% greater weekly survival than plots with small mammals in the Mojave and Great Basin Deserts, respectively. In addition, burned plots had greater seedling survival than unburned plots in the Great Basin, but there was no effect of fire in the Mojave Desert. There appears to be significant interactions betweeen small mammals and fire in both deserts. Our results illustrate that the role of granivorous small mammals extends beyond dispersal and granivory to the seedling stage of plant life cycles. Moreover, small mammal-mediated folivory during the seedling stage may be equally or more important for plant survival than both dispersal and granivory of seeds. These results have important implications for post-fire revegetation efforts and recovery of desert plant communities.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.