9310006 Trappe Research is proposed to determine whether mycorrhizal fungi accelerate plant community development. A series of greenhouse and field studies at the Lyman Glacier forefront in Washington are planned to test: whether VAM enhance the survival and growth of early colonizers; whether surviving mycorrhizal plants allow greater mycorrhizal fungal diversification; and whether the resultant positive feedback between plant establishment, environmental modification, and fungal diversification ultimately increase rates of community development and system carbon accretion. Specifically, researchers will measure how mycorrhizal formation and soil carbon accretion vary as a function of distance from existing plant islands; how mycorrhizal fungi, environmental modification by established plants, soil organic matter, and inorganic nitrogen and phosphorus affect new plant survival and colonization in the field; and test the ability of dark septate endophytes to act as bridges between established plants and colonizing plants. %%% Results of these studies would provide evidence on the degree to which mycorrhizae are responsible factors aiding plant colonization, particularly in nutrient poor, harsh environments. ***
