Globally, mycorrhizal fungi are likely to sequester a substantial amount of carbon in their living and dead tissues and through the production of recalcitrant compounds such as chitin and glomalin. Dr. Treseder and colleagues will test the hypothesis that increases in nitrogen availability in soils will reduce the immobilization of nutrients in this mycorrhizal material, because nitrogen additions may decrease mycorrhizal growth but increase death rates and decomposition of dead tissue. If this is the case, increasing nitrogen deposition could reduce soil carbon storage and accelerate the current rise in atmospheric CO2 levels. The investigators will employ field and laboratory techniques to assess the effects of nitrogen fertilization on mycorrhizal carbons. The findings will be evaluated in the context of potential interactions between nitrogen deposition and elevated atmospheric CO2, and with possible implications for natural and agricultural ecosystems
