Rodent population and community responses to forest-based biofuel production

Abstract

Intensively managed forests in the southeastern United States are a potential source of cellulosic bioenergy and, as conversion technologies improve and demand increases, a greater land area may be required to produce biofuel feedstocks. However, responses of wildlife to forest-based biofuel production are largely unknown. We examined the 4-year response of rodent populations and assemblages to a range of biofuel production regimes, including harvesting residual woody debris and intercropping switchgrass (Panicum virgatum), in an intensively managed loblolly pine (Pinus taeda) forest in eastern North Carolina, USA. We investigated abundance, demography, and community response of rodents in a randomized and replicated field experiment using mark-recapture techniques during 2009–2012. Whereas removal of downed woody biomass did not affect abundance, diversity, or demography of rodents, we detected species-specific effects of incorporating switchgrass. After switchgrass was well established, invasive house mice (Mus musculus) were most abundant in plots with switchgrass. In contrast, white-footed mice (Peromyscus leucopus) were commonly captured in plots without switchgrass and other rodents were not affected by biofuel treatments. Across the study, natural succession exerted greater effects on rodent species and the rodent community than biofuel production regimes. As remaining logs and stumps decay and become limiting, downed wood may become more important to rodents. Our results indicate that intercropping switchgrass and harvesting residual woody material had limited effects on rodents in the Coastal Plain of North Carolina, USA within 4 years of stand establishment.