Carbon and nutrient mineralization and fungal spore composition of fecal pellets from voles in Minnesota

Numerous investigators have suggested that small mammals may regulate ecosystem processes because they couple producers and decomposers through deposition of fecal materials and by dispersing spores from mycprrhizal symbiotic fungi. We investigated carbon, nitrogen, and phosphorus mineralization rates from feces of two arvicoline rodents, Clethrionomys gapperi and Microtus pennsylvanicus , common in the forests of the Lake Superior region. We also examined fungal spore composition from these feces. Mineralizable pools of C and N and their decay rates were higher in feces from C. gapperi than from M. pennsylvanicus , but there were no differences in sizes of mineralizable pools of phosphorus. Feces of C gapperi contained four times more fungal spores than those of M. pennsylvanicus. Twenty‐three fungal genera were represented in these feces, and all but one genus have predominantly ectomycorrhizal forms. Fungal species composition also differed significantly between the two arvicoline species. Although the amount of N and P mineralized annually from populations of these two species is small compared with nutrient budgets for the forests as a whole, these species may be important in dispersing spores and labile nutrient pools to microsites of seedling establishment.