SURFACE MINING INTERACTS WITH TIMBER HARVESTING TO FACILITATE THE INVASION OF WOODY INVASIVE SPECIES IN A TEMPERATE FOREST OF CENTRAL APPALACHIA, USA

Appalachian forests are subjected to various short- and long-term anthropogenic disturbances. Surface mining is among the most potent drivers of land use change in the Appalachian region, reducing native forest cover and causing landscape fragmentation. Furthermore, the ecological footprint of surface mining could be expanded to adjacent forests, and such spill-over effects may be exacerbated by in-situ forest disturbances such as timber harvesting. However, it remains elusive how these two disturbance agents may be compounded to degrade forest health and landscape integrity. One of the major threats to forest health in the Appalachian forests is the invasive species. Many woody invasive species can produce prolific seeds and, when the environmental conditions are conducive, can colonize and occupy a forest floor, eventually reducing the regeneration of native species. An observational experiment was conducted to determine the effects of timber harvesting and mining on the invasion of woody invasive species. 407 50th-acre plots were deployed across four watersheds within Robinson Forest, a 14,800-acre experimental forest in eastern Kentucky. The four watersheds differ in harvesting history and adjacency to surface mining. The Two-way ANOVA results showed that the main effects of timber harvesting and mining adjacency and their interaction effect were statistically significant (p-value < 0.001) in affecting the richness and abundance of woody invasive species. Post-hoc analysis showed that plots in the recently harvested watersheds tended to have more woody invasive species than in unharvested watersheds, irrespective of adjacency to mining. Mining adjacency exacerbated the invasion of woody species, with the harvested watershed adjacent to mining showing the highest richness and abundance of woody invasive species. This study highlights the need to incorporate the spill-over effects of surface mining into the consideration of best management practices of the temperate forests in central Appalachia and the regions with similar landscape-level disturbance characteristics.