Restoring habitats that have been invaded by exotic, non-native plant species is often challenging. Efforts to promote success of desired species must be balanced with efforts to control detrimental exotic species. Furthermore, likelihood of success and cost of successful restoration can vary dramatically among equivalently invaded habitats and thus are difficult to predict. In this project, wetlands and grasslands in Texas invaded by exotic Chinese tallow trees will be used as a model system to better understand mechanisms driving restoration outcomes. The necessary and appropriate management methods (and thus cost) depend on how intensely tallow trees return following their removal. This is hypothesized to depend on soil moisture and the local availability of tallow and native plant seeds. At 12 tallow-invaded habitats located across a moisture gradient, moisture, native seed availability, tallow seed availability and management methods will be manipulated. Experimental results and data on initial habitat characteristics from each site will be used to develop a model that predicts restoration outcomes based on site characteristics. In addition to advancing understanding of how environmental factors influence invasions and plant community development, this work will have broader impacts for conservation and restoration. The ability to predict restoration outcomes could allow land managers to prioritize efforts where chances of success are high and costs are low. This would increase the extent of successful restoration and tallow control on a landscape scale, benefiting wildlife as well as land managers and landowners struggling with tallow.
