Laura Finkes Indirect Effects of Endophyte Infection on the Distribution and Abundance of Spiders in Tall Fescue (Festuca arundinacea) Division Sciences Department Biology Year 2004 Advisor Juliana Mulroy

The importance of fungal endophytes in pair-wise interactions between grasses, herbivores and other plants is well established, but ecologists are just beginning to understand the importance of endophytic fungi at the community level.  In this research, I review literature regarding the importance of endophytic fungi in pair-wise interactions as well as recent literature on the community level impacts of grass-endophyte symbioses.  Following the literature review, I present my own field research investigating the indirect effects of endophytes and structural complexity on the distribution and abundance of spiders in old fields.  I experimentally manipulated endophytes and thatch in fields of tall fescue.  I found that fungal endophytes strongly reduce the species richness of spiders as well as the abundance of some     spider families.  I also explore one potential mechanism underlying these results, endophyte mediated plant interactions, in a greenhouse experiment using tall fescue and Conyza canadensis.