Tiffany Betras, Carson Lab
Understanding the causes of biodiversity declines in temperate forests: Disentangling the impacts of browsing and nonnative plant species
Overbrowsing by high populations of white-tail deer, the invasion of nonnative plant species, or both together likely underlie dramatic declines in biodiversity throughout the Eastern Deciduous Forest Biome. To date, few studies have used experimental approaches to rigorously tease apart these two critical drivers. Here, I use a wide variety of approaches including large-scale field experiments, mesocosms designed to quantify soil feedbacks, and observational studies to evaluate how each driver alone or together can shape forest communities. Results to date demonstrate that invasive species and deer together create a near alternative stable state composed of depauperate plant communities dominated almost entirely by invasive plants and highly browse-tolerant native plant species. Observational studies provide parallel support that browse-sensitive species are often restricted to refugia.