LTREB: The population dynamics of forest understory invasion: mechanistic experiments with generalist herbivores, natives, and invaders

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

Using long-term experimental plots that exclude deer (native plant consumer) and garlic mustard (allelopathic forest invader), this investigator previously demonstrated that 1) over-abundant deer facilitate forest invasion by garlic mustard, 2) the presence of both garlic mustard and deer cause native perennial herb populations to decline, and 3) deer and garlic mustard negatively affect forest soil characteristics. The proposed research will extend and expand the seven-year dataset on key focal native herbaceous forest understory species to analyze the effects of deer and garlic mustard on population demography of the focal species. Integral Projection Models, a powerful new demographic method, will be employed to predict the long-term persistence or extinction of the focal species under different deer and invader scenarios generated by these experiments. This research will return novel insights into the direct, indirect and synergistic interactions of the powerfully disruptive duo, deer and garlic mustard, on the sustainability of forest native plant populations and the forest plant community as a whole. Invasive species and overabundant deer threaten the functional integrity of native ecosystems and cause billions of dollars in economic losses annually. Results of this research will yield needed information on the effects of deer and garlic mustard to forest ecosystem managers by expanding our basic understanding of multi-species trophic forest interactions (deer, invader and natives). These researchers will continue outreach efforts and community engagement via public lectures, the development of a high school teacher workshop based on our findings, service on a non-profit board and community organizations, and through continued development of Virtual Trillium Trail (VTT), a computer gaming platform that provides a virtual field trip through our field site based on our field data. The effectiveness of VTT as a learning tool has been rigorously assessed with middle school students. Research training will include undergraduate and graduate students and a post-doctoral fellow.