Two of the most fundamental questions in ecology still remain poorly understood: First, although every ecological community is a subset of the local pool of all available species, what factors determine which species coexist together? Second, how does the outcome of community assembly (the composition and biodiversity of the communities) affect the basic functioning of the ecosystem? These questions remain poorly answered partly because ecosystems are characterized by many factors that vary simultaneously. Important factors affecting how communities are assembled include: the chance history of species arrival, competition for resources, and interactions with beneficial species. Rather than ignoring some of this variation or simply trying to demonstrate that one particular factor can affect communities, the investigators are using an integrative approach to better understand the relative importance of these factors in affecting prairie plant and soil fungal communities. The investigators will also address the relative importance of these factors in determining plant production, nitrogen cycling, and soil carbon storage, all of which are critical ecosystem processes. This research will also examine key attributes of the focal plant species, and this will provide for greater generality when comparing to other regions with different species. With less than 1% of the original prairie habitat remaining, this project will provide valuable information for restoration efforts and soil conservation. Undergraduate and graduate students will also design their own experiments that will piggy-back on the larger project. This outdoor laboratory will similarly provide educational opportunities for the local community.