Ecosystem ecology of the golden mouse

Abstract

Various mammalian examples of dominant species such as the white-tailed deer (Odocoileus virginianus; Seagle 2003), keystone species such as the blue wildebeest (Connochaetes taurinus; McNaughton et al. 1988), and ecological engineers such as the beaver (Castor canadensis; Naiman et al. 1994) have been described, clearly representing species that strongly influence various aspects of ecosystem structure and function. Small rodents have also been noted to strongly affect pattern and change in ecosystems. For example, Stephen's kangaroo rats (Dipodomys stephensi) influence the composition and spatial pattern of plant communities through their burrowing and foraging activities (Brock and Kelt 2004). Similarly, black-tailed prairie dogs (Cynomys ludovicianus) create hot spots of vertebrate diversity (Lomolino and Smith 2003) and unique vegetation composition and structure that facilitate nutrient and energy flux (Fahnestock and Detling 2002). Rodents have long been proposed as a significant vector for dissemination of fungal spores in forests of the Pacific Northwest (Maser et al. 1978). More recent studies continue to highlight the extent of mycophagy in small rodents (Colgan and Claridge 2002, Orrock and Pagels 2002) and the potential for consumption and passage through small mammals to enhance the germination and the inoculation potential of spores (Caldwell et al. 2005). Based on various studies, Inouye et al. (1987) suggested a positive feedback among arvicoline rodent consumption of plant material, subsequent deposition of nutrients in fecal matter or urine, and regrowth of food plants. Pastor et al. (1996) found that the total amounts of nitrogen and phosphorus mineralized by meadow voles (Microtus pennsylvanicus) and red-backed voles (Clelhrionomys gapperi) were relatively small components of the nutrient budgets for a 13-year-old forest stand. They did note, however, that localized fertilization and spore dispersal to microsites of seedling regeneration might significantly impact forest dynamics. In contrast to localized impacts, Clark et al. (2005) estimated that rodents in an Oklahoma old field deposit fecal and urinary nitrogen in amounts comparable to large herbivores and other system nutrient fluxes and thus represent an integral part of the terrestrial old-field nitrogen cycle. This list of small mammal interactions with ecosystem structure and function is highly abbreviated (Hayward and Phillipson 1979), but it does highlight the variety and extent of small mammal impacts on ecosystems and prompt the question: What is the role of the golden mouse (Ochrotomys nuttalli) in forest ecosystems? © 2008 Springer Science + Business Media, LLC.