Evaluating Remote Sensing and Prescribed Fire Methods to Aid in the Restoration of Bottomland Hardwood Forests Invaded by Chinese Privet (Ligustrum sinense)

Abstract

Chinese privet (Ligustrum sinense Lour.) is an invasive shrub with a wide distribution outside its native Southeast Asia range. It is particularly common and problematic in the southeastern U.S., where researchers have documented negative impacts to woody and herbaceous plant communities, which in turn likely affects wildlife habitat quality. This research project evaluated two management tools that could assist land managers in efforts to restore bottomland hardwood forests that have been invaded by L. sinense. Our first objective was to evaluate whether free multispectral satellite imagery and free simple-to-use software could be used to map L. sinense invasions and aid in planning and budgeting restoration projects. We found that the Semi-Automatic Classification Plugin within QGIS was effective at detecting L. sinense, particularly when using late dormant season Sentinel 2 imagery. Our second objective was to evaluate whether prescribed fire could reliably move through bottomland hardwood forests and reduce L. sinense slash following cutting operations to improve the efficiency of follow-up treatments on re-sprouts. We found that stand composition had the most important effect on fire spread (plots with greater proportions of tree species with flammable leaf traits tended to burn best), but that the fires were only successful in a limited number of cases. Only small diameter L. sinense slash was significantly reduced, and more research is needed to determine whether prescribed fire is beneficial in this context.