Herbivory by terrestrial gastropods, particularly Arion sp. (a non-native slug), can alter epiphytic lichen communities; however, little is known about this interaction in forests of North America. We used surveys of grazing damage to lichen thalli in the field on 52 plots within Hubbard Brook Experimental Forest, NH. Grazing damage by terrestrial gastropods was widespread, though few sites had severe grazing. Grazing damage was significantly higher on flatter terrain and on broadleaf trees. Overall, lichen communities in the HBEF were moderately impacted by terrestrial gastropod grazing, but potential effects of the non-native slugs at higher elevations and impacts on lichen health of widespread, moderate grazing deserve further study.
These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the USDA Forest Service, Northern Research Station.