A Survey of Cavity-Nesting Bees and Wasps in Loblolly Pine Stands of the Savannah River Site, Aiken County, South Carolina
In recent years concern over widespread losses in biodiversity has grown to include a possible decline of many native pollinators, primarily bees (Buchmann and Nabhan 1996, The Forgotten Pollinators, Island Press). Factors such as habitat fragmentation, agricultural practices, use of pesticides, the introduction of invasive species, or changes in land use may negatively impact these vital organisms (Kearns et al. 1998, Ann. Rev. Ecol. Syst. 29: 83-l 12). Most reported studies show that human impacts on pollinators are overwhelmingly negative (Vinson et al. 1993, Hymenoptera and Biodiversity, CAB International; Buchmann and Nabhan 1996). Because 60 to 70% of plant species rely on insects for pollination (Richards 1986, Plant breeding systems, Chapman and Hall), reductions in pollinator populations may profoundly impact plant population dynamics (Bond 1994, Philos. Trans. R. Sot. Lond. B. Biol. Sci. 34: 83-90). Consequently, decreases in native pollinator diversity and abundance may severely impact ecosystem function.