Community responses of litter dwelling ants to removal and exclosure of invasive Amur honeysuckle (Lonicera maackii) and white-tailed deer (Odocoileus virginianus)

Traditional ecological studies have separated above and belowground food webs, however, it is becoming clear that the two food webs are intrinsically linked. Over the last century Ohio’s deciduous forests have been altered by two invasive species: white-tailed deer (Odocoileus virginianus) and Amur honeysuckle (Lonicera maackii). Deer are keystone species altering the plant community composition through selective herbivory and overabundance. Amur honeysuckle is a highly competitive, introduced shrub that shades native plants and affects moisture, temperature, and nutrient availability of soils. Ants are significant members of forests, interacting in both above and belowground communities by dispersing seeds and enhancing decomposition. Ant communities are sensitive to environmental change and can be used as bio-indicators. In this study we test the effects of deer and honeysuckle on ant communities using a removal and exclosure experimental design.

Paired, fenced deer exclosure and open control plots (20m²) were established in 2010 in five of Miami University’s Natural Areas. Honeysuckle was removed from half of each plot. We sampled leaf litter ant communities with Winkler funnels. We used generalized linear mixed models to test deer and honeysuckle effects on ant composition, richness, and abundance. Baseline 2011 collections showed no effects of deer or honeysuckle on ant variables. Data from 2013 showed no effects on ant richness or community composition, but significantly higher ant abundance in the presence of deer and honeysuckle. The results suggest that these invasive species, known to affect the aboveground communities, may also be affecting important members of belowground communities.