Objective

Biological invasions by non-native invasive species (NIS) are a major cause of native ecosystem degradation. This is particularly true for grasslands in North America, where non-native plants can dominate grasslands following soil disturbance and become persistent problems for land managers. Disturbance may facilitate dominance by non-native plants because it destroys the native soil community on which native plant species depend, including symbiotic fungi. Arbuscular mycorrhizal (AM) fungi form symbiotic associations with plant roots and aid in plant uptake of limiting soil resources such as phosphorus, nitrogen, and water. In exchange, plants deliver carbon to their obligate symbionts in the form of sugars. Disruption of the association of native plants with AM fungi can reduce rates of carbon sequestration and reduce soil aggregate stability, thereby potentially contributing to soil erosion. Restoration of native AM fungi can help restore native plants and ecosystem function of grasslands.

The objective of this project is to evaluate the potential benefits of native soil fungal inoculation to control non-native plant invasions and enhance restoration of ecosystem function at U.S. military installations. Researchers specifically will test whether disturbance of soil results in reductions in density and diversity of AM fungi, reductions in aggregate stability, and facilitation of invasion by NIS. Researchers also will test whether inoculation with native AM fungi at disturbed sites will improve the establishment of native plant species, suppress NIS, and restore soil aggregation while increasing soil carbon sequestration. Finally, researchers will evaluate whether changes in soil communities due to global climate change (e.g., warmer temperatures, increased droughts, and increased climatic variability) will alter plant-AM fungal interactions.