Wildlife Responses to Long-Term Application of Biosolids to Grasslands in North Carolina

Abstract

Applications of biosolids to grassland areas might alter the attractiveness of those habitats to wildlife. For the past 21 yr, biosolids have been applied annually to grasslands at Marine Corps Air Station (MCAS) Cherry Point, Havelock, North Carolina. During 2003-2005, we conducted a study to determine if the long-term application of biosolids has altered plant communities and/or wildlife use of grassland areas. Ten circular 1.7-ha plots were established: five plots served as controls (untreated) and five plots were located in areas that received biosolids. We monitored vegetation growth, measured plant community composition, and observed all plots for wildlife activity during December 2003 through December 2005. Long-term application of biosolids to grasslands at MCAS Cherry Point has altered the botanical structure and composition of those areas. Plant communities in grassland areas receiving biosolids were taller (P < 0.001), denser (P < 0.001), and less diverse (P < 0.001) than control areas that did not receive biosolids. Biosolids study plots were dominated by tall fescue (Lolium arundinaceum [Schreb.] S.J. Darbyshire), whereas control plots consisted of a diversity of grasses, forbs, and woody plants. We observed more (P < 0.001) total birds 3-min survey-1 using biosolids treatment plots (6.7 +/- 0.5 birds; x +/- SE) than birds using control (2.6 +/- 0.2 birds) plots. Species-specific differences in use of biosolids and control grasslands did occur and was often related to season. We observed no differences in white-tailed deer (Odocoileus virginianus) use of biosolids and control areas when examining information from two types of deer surveys. Long-term biosolids application to cool-season grasslands alters plant communities and favors use of those areas by some grassland birds.