Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area

Following the planting of several thousand hardwood seedlings in a 69-ha we tland restoration area in west-central South Carolina, USA, wild pigs (Sus scrofa) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation effort to restore a bottomland hardwood community in the corridor and delta of a third order stream that had been previously impacted by the discharge of heated nuclear reactor effluent. Th e depredated restoration areas had been pretreated with both herbicide and control burning prior to planting the hardwood seedlings. After discovery o f the wild pig damage, these areas were surveyed on foot to assess the magn itude of the depredation on the planted seedling crop. Foraging by the loca l wild pigs in the pretreatment areas selectively impacted only four of the nine hardwood species used in this restoration effort. Based on the survey s, the remaining five species did not appear to have been impacted at all. A variety of reasons could be used to explain this phenomenon. The pretreat ment methodology is thought to have been the primary aspect of the restorat ion program that initially led the wild pigs to discover the planted seedli ngs. In addition, it is possible that a combination of other factors associ ated with odor and taste may have resulted in the selective depredation. Fu ture wetland restoration efforts in areas with wild pigs should consider pr etreatment methods and species to be planted. If pretreatment methods and s pecies such as discussed in the present study must be used, then the prior removal of wild pigs from surrounding lands will help prevent depredations by this non-native species. (C) 2000 Elsevier Science B.V. All rights reser ved.