Various types of species interactions including competition, herbivory, and mutualisms, as well as disturbance and other processes operating at different spatio-temporal scales may influence the structure and diversity of plant communities. Many of these processes have been studied independently, but the interactions between these various organizing influences are not understood. Asses how a mutualism (Vesicular-arbuscular Mycorrhizae (VAM) and plant competition interact to shape grassland community structure within the natural context of a variable regime of large scale disturbance. Co-occurring plant species may respond differentially to the effects of VAM fungi, and these differential responses to VAM fungi may strongly influence plant competition and community sturcture. The objectives of this research are to 1) assess the importance of VAM determine how VAM fungi influence competition among co-occurring plants which vary in mycorrhizal dependence at both the seedling and established plant stage, and 3) to understand how mycorrhizal-mediation of these processess influences plant community structure. Tallgrass prairie represents an ideal system for the proposed studies because both mycorrhiza dependent grasses and forbs (obligate mycotrophs and relatively independent species (facultative mycotrophs) coexist as important species and compets for resources. //
