Habitats around the world are experiencing species losses, biotic homogenization, and invasions of non-native species. We are documenting these processes by systematically resurveying forest plant communities first surveyed 50+ years ago in the upper Midwest of the United States. We have re-sampled ~300 sites in upland and lowland forest habitats within areas of high and low habitat fragmentation.
Results/Conclusions Our work confirms that all three processes are occurring in Wisconsin forests even in the absence of direct habitat destruction or conversion. Differences among sites in the rates of species loss, homogenization, and invasion implicate particular drivers of ecological change including succession, habitat fragmentation, and herbivory by white-tailed deer. Exotic earthworm invasions, climate change, and other factors are also affecting community dynamics. We are investigating the mechanisms driving these shifts in community composition by exploring how plant functional traits affect the distribution and abundance of species within and among sites experiencing contrasting ecological conditions. We are using an extensive database on plant functional traits to evaluate how ecological conditions interact with species characteristics to affect the dynamic processes of colonization, persistence, and local extinction.
