The influence of managing a loblolly pine (Pinus taeda) forest for biofuels production via switchgrass (Panicum virgatum L.) intercropping and woody debris removal on rodents

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Matthew M. Marshall (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Matina Kalcounis-Rüppell

Abstract: The abundance and distribution of wildlife communities can be influenced by many factors including resources, competitors, predators and parasites, and climate. Changes to managed forest understory composition and structure may affect ecologically important rodent communities. Furthermore, diversity of rodent communities can correlate with vertebrate biodiversity across a diverse range of ecosystem types. To help meet demands for renewable sources of energy, biofuel feedstock production options include intercropping switchgrass (Panicum virgatum L.) within intensively managed loblolly pine (Pinus taeda) stands, and removal of residual woody debris. The objective of my study was to experimentally examine rodent responses to these options. I surveyed rodent populations using mark-recapture techniques to determine their responses to pine and switchgrass intercropping and residual woody debris removal. For 6 months in 2009, and 5 months in 2010, we captured rodents on experimental plots within newly established pine plantations that were subjected to five different treatments that involve biomass removal. Habitat measurements conducted in 2010 on percent cover and height of habitat types reflected differences among the 5 treatments as indicated by a significant interaction of habitat type (i.e. grass, pine, etc.) among biomass removal options and across sampling dates from April to October. This interaction indicates the preparation of the study plots created habitats that differed in structure. Rodent community diversity metrics including species richness, Shannon Diversity index, and Fisher's á index were not influenced by biomass removal options in either 2009 or 2010. In 2009, treatments did not influence the abundance of any species. However, there was a trend for house mice (Mus musculus) and hispid cotton rats (Sigmodon hispidus) adults to be more abundant in habitats with switchgrass. In 2010, treatments significantly influenced the abundance of the number of unique individuals and total captures of white-footed mice (Peromyscus leucopus), M. musculus, and S. hispidus of. During the second year of study, P. leucopus adults showed highest abundance in non-switchgrass habitats, intermediate abundance in pine and switchgrass intercropped habitats, and lowest abundance in switchgrass only habitats. Additionally, P. leucopus juveniles showed a trend to be more abundant in habitats without switchgrass, suggesting differences were a result of P. leucopus reproduction in these habitats. M. musculus abundance was highest in switchgrass only habitats, intermediate in pine and switchgrass intercropped habitats, and lowest in habitats without switchgrass. Mus musculus juveniles showed a trend for higher abundance in habitats with switchgrass suggesting differences were a result of M. musculus reproduction. Abundance of S. hispidus tended to be higher in habitats with pine and switchgrass intercropped than habitats without switchgrass and habitats with only switchgrass. Juvenile abundance of S. hispidus did not differ among biomass removal options, suggesting all habitats in this study provided similar resources for S. hispidus reproduction. My results suggest residual woody debris removal has no influence on rodent population abundance, incorporation of switchgrass intercropping has an intermediate influence on rodent population abundance, and planting only switchgrass has a significant influence rodent population abundance. Switchgrass habitats supported higher abundance of the invasive M. musculus, and lower abundance of the native P. leucopus than habitats without switchgrass. Thus, forest managers may want to consider introducing switchgrass exclusively to interior forest stands, that are far from potential M. musculus source populations (e.g., agricultural fields and residential buildings. This strategy could also benefit native species that avoid switchgrass, such as P. leucopus, by providing refuge areas devoid of switchgrass in exterior stands. A better understanding of rodent responses to forest management will be beneficial in maintaining biodiversity and the sustained use of the services provided by forest habitats.

Additional Information

Language: English
Date: 2011
Biodiversity Management, Biofuels, Habitat Resources, Loblolly Pine, Rodent, Switchgrass
Rodent populations $x Effect of forest management on $z North Carolina
Rodents $x Habitat $z North Carolina
Loblolly pine $x Research $z North Carolina
Switchgrass $x Research $z North Carolina
Forest management $x Research $z North Carolina

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