Effects of Invasive Amur Honeysuckle (Lonicera maackii) and White-Tailed Deer (Odocoileus virginianus) on Litter-Dwelling Arthropod Communities

Litter-dwelling arthropods play crucial roles in litter decomposition and nutrient cycling, and changes in their diversity or abundance can affect these processes. Previous studies have outlined individual effects of invasive plants and overabundant ungulates on litter-dwelling arthropod communities hut have paid little attention to whether invasive plants and ungulates interact to affect these arthropod communities. We examined how invasive Amur honeysuckle (Lonicera maackii) and grazing by white-tailed deer (Odocoileus virginianus) affected diversity, abundance, and taxonomic composition of litter-dwelling arthropod communities in a deciduous forest in southwestern Ohio. We also examined whether deer or honeysuckle affected substrate composition and depth of litter. We found no significant effect of honeysuckle, deer, or their interaction on arthropod diversity, but exclusion of deer increased total arthropod abundance and abundance of Araneae, and thereby affected taxonomic composition of the litter community. These effects were likely related to greater plant cover and less soil compaction in areas front which deer were excluded. Honeysuckle negatively affected Araneae abundance and positively affected Acari abundance, possibly revealing an indirect effect of Araneae on Acari. A honeysuckle X deer interaction on abundance of Acari was important only during the first year of our study. There were no differences in arthropod abundance between honeysuckle-absent and honeysuckle-removed plots, indicating rapid restoration of the litter community after honeysuckle removal. Neither honeysuckle nor deer affected composition or depth of litter. Our findings suggest that current management techniques that control the effects of honeysuckle and deer on native plant communities by separate measures may be sufficient to reduce impacts on litter-dwelling arthropods.