Nonnative invasive plants (NNIP) have far-reaching effects on native ecosystems worldwide. Understanding the role of generalist seed dispersers in spreading NNIP across the landscape is important to the conservation of native ecosystems and to the management of NNIP. We studied white-tailed deer (Odocoileus virginianus) as a seed disperser in a mixed maritime pine (Pinus spp.) forests on Parris Island, SC, with particular interest in the dispersal of Chinese tallowtree [Triadica sebifera (L.) Small], a highly invasive tree species in the southeastern United States, which is a management concern on Parris Island, SC. We collected deer scat pellet groups along transects in two forest types: those that had recently been treated with silvicultural timber harvest (thinned) and those that have not been so treated (unthinned). Using two pellet-treatment methods, directly planting or rinsing and sorting, we determined that, out of 25 species grown under greenhouse conditions, 28% (n  =  7) were nonnative, small-seeded, herbaceous species. However, T. sebifera was not identified in either of the two treatment methods. Recent forest thinning significantly affected the number of species determined in deer pellet groups (F  =  8.37; df  =  1; P < 0.01), with more native plant species identified in unthinned (x̄  =  25 ± 11) than in thinned (x̄  =  3 ± 10) forest stands (F  =  5.33; df  =  1; P  =  0.02). Our results indicate that white-tailed deer are actively dispersing nonnative seeds but not those of T. sebifera or other woody NNIP.

Nomenclature: Chinese tallowtree; Triadica sebifera (L.) Small; pine; Pinus spp.; white-tailed deer; Odocoileus virginianus.

Management Implications: Our study investigated whether white-tailed deer (Odocoiles virginianus) were active dispersers of Chinese tallowtree (Triadica sebifera) and other nonnative invasive plants (NNIP) in mixed maritime pine (Pinus spp.) forests at Parris Island Marine Corps Recruit Depot (MCRD), Parris Island, SC. Dispersal by generalist herbivores can lead to the establishment of NNIP in new, potentially uninvaded locations resulting in changes in ecological trajectories that can directly affect management activities. We determined that white-tailed deer were not dispersing T. sebifera but were active dispersers of other nonnative plants. White-tailed deer are ubiquitous, generalist herbivores that are overabundant in many areas of the eastern United States. When overabundant, or when native plant resources are lacking during periods of nutritional stress, white-tailed deer will alter their forage choices and select alternative plant species. Forest management activities (i.e., timber harvesting operations, prescribed burning, etc.) may provide the necessary conditions for nonnative plant establishment through increased solar radiation and mineral soil exposure and should be considered if mitigating invasive species spread.