The consequences of biological invasions range from threats to biodiversity and human health to the high economic costs of mitigation; therefore, identifying the mechanisms behind introduction and maintenance of invasive species in communities is crucial. In Midwest prairies, invasive non-native plant species have been seen to directly compete with natives, resulting in a change in community structure and the foraging behavior of animals. Lesser understood is the role of apparent competition in increasing consumer pressure on native plant species. Examining this relationship will help to understand why restoration efforts are unsuccessful in establishment and persistence of native plant species.

On the campus of SIU Edwardsville, established populations of Chinese lespedeza (Lespedeza cuneata), a highly invasive plant, appears to greatly increase small mammal herbivory on native plants, eventually extirpating native grasses. In this study, experimental exclosures were used to determine the impacts of herbivory on the growth of three native plant species (Sporobolus heterolepis, Solidago speciosa, and Penstemon digitalis) and how predation rates differ between plots of semi-natural grassland and plots invaded by lespedeza.

Plant herbivory only existed outside of exlcosures, confirming that vertebrates, rather than invertebrates, were responsible for herbivory. At all paired sites, plant herbivory was 30-50% greater in invaded plots than in native grassland plots. This is likely due to herbivores encountering a food desert, which led them to consuming the only palatable food source present.