Fire is a critical tool for maintaining plant diversity in tallgrass prairies. However, little is known about how prescribed fire timing affects prairie plant communities. While most prescribed fires throughout the tallgrass prairie occur in the spring, there is evidence that fall prescribed fire can drastically affect the productivity and phenology of different plant groups. In addition, Midwestern regional climate change predictions suggest that the winter climate will change considerably, resulting in less snow and more freeze-thaw cycles in spring and fall. The effects of fire timing and winter climate change have strong potential to interact in ways that will influence prairie vegetation responses in the future. To most effectively apply prescribed fire in the face of climate change, understanding vegetation responses to this interaction will be critical. This topic has been identified by managers and scientists as a key area of interest where knowledge is lacking. The results of this study will provide important information on the future effects of fire on prairie plant communities in the face of rapid winter climate change. To address this issue I propose to set up a field experiment in a southern Wisconsin remnant prairie. This experiment will involve manipulating snow depth with a snow fence and four experimental plot types including fall prescribed burn, spring prescribed burn, litter removal, and control plots. The effects of snow depth, fire timing, and their interaction on prairie plant growth and reproduction, phenology, and seedling recruitment will be assessed yearly in experimental plots. It is expected that different plant guilds will respond differently to burn timing where C4 grasses will be inhibited while forbs and C3 grasses will be promoted by fall burns. Stress tolerant species should benefit from lower snow depth due to the longer growing season that is coupled with higher potential for growing season frosts. The interaction between snow depth and fire timing is expected to be mediated by the presence of litter as an insulating layer.