Mutualisms are vital to plant survival and reproduction, but climate warming has the potential to alter these interactions. One such mutualism involves foliar mites, which provide plants with defense by consuming harmful fungi. In exchange, plants offer protective structures on their leaves called domatia. Both mite and fungal communities are potentially temperature-sensitive, and warming may shift community composition, potentially altering trophic interactions between botch groups. However, the specific changes in mite and fungal community composition and their implications for plant-mite mutualism and plant performance remain unclear. To investigate the responses of both of these communities to warming, and the effects these changes will have on plants, I conducted a nested factorial field experiment with 96 P. serotina seedlings at the University of Michigan Biological Station. Plants were warmed using open top chambers, nested within which were fully factorial manipulations of the mite and fungal communities. Each group was manipulated using either pruning tar to exclude mites or Quilt fungicide to exclude fungi.