Speaker

Dr. Matthew McCary
Ford Foundation Postdoctoral Fellow
Yale University

Abstract

Soils contain the most diverse community of organisms in terrestrial ecosystems, with essential roles in nutrient cycling and food-web dynamics. Human-induced disturbances remain a significant threat to the structure and functioning of soil communities, yet our understanding of how they respond to environmental change is limited. I present two examples (i.e., plant invasion and resource subsidies) of how environmental change can influence soil community dynamics. First, I show how garlic mustard (Alliaria petiolata)—a widespread North American plant invader—re-structures soil food webs by changing fungal composition and biomass. In a second study, I show how aquatic insect subsidies can affect subarctic soil communities by adding novel resources, resulting in increased microbial activity, litter decomposition, and plant biomass. Together these two studies illustrate that soil communities are highly sensitive to resource changes in the environment, leading to shifts in ecosystem processes and plant community dynamics.