Organisms are embedded within food webs in which they interact directly and indirectly with other species. While many studies have shown the importance of direct and indirect interactions in altering community structure (i.e. species abundance and diversity), much of this work has focused on changes in the density of the component species. However, there is growing evidence from short-term experiments (i.e. = 1 generation) that changes in the traits of species can lead to similar results independent of changes in density. If changes in species traits lead to similar effects as density they may be equally important to the long-term structure of ecological communities. Our proposed research will implement a long-term approach to examine the relative importance of changes in species' density versus species' traits to the structure of ecological communities. Our research also offers a number of broader impacts. We have an excellent record of incorporating underrepresented groups (minorities and women) into our research. Our students are actively engaged in the research and are encouraged to develop their interests into experiments that supplement our own work and expand it in new directions. These students have presented their research at scientific meetings and published their results in top-tier journals. Thus, undergraduates learn the skills necessary to develop as scientists including how to publish their results. In sum, our results will be disseminated in seminars presented to national and international audiences, webpages that present our research to scientific and public communities, and in the popular press including with worldwide readership.
