The Role of Soil Microbes in Plant Invasions: Inhibition at Home and Facilitation Away?

University Of Montana, Missoula MT

Investigators

Abstract

A major unanswered question in biology is why some exotic plants attain very high densities and wreak havoc in communities where they are introduced, but are minor components of their native communities. This project is a broad international research program to test an emerging hypothesis for the success of invasive plants - that soil fungi control exotic invasive plants in their native communities, but not in the communities that these exotics invade. This research will involve field experiments in North America and Eurasia to test the effect of soil fungi on spotted knapweed (Centaurea maculosa) and leafy spurge (Euphorbia esula) and how soil fungi interact with human-caused disturbance. As well, to generalize beyond these two invaders, plant-soil microbial feedback experiments will be conducted to determine how the strength of positive and negative soil feedback differs between native and introduced soil. This research has the potential to change the way we understand and respond to exotic plant invasions. Invasive organisms cause billions of dollars of damage annually, and the United States invests substantial funding into chemical and specialist insect based control of weeds. Instead, if soil fungi play an important role in invasive success, a reorientation of our efforts to fight weeds would be warranted.