CAREER: When do mycorrhizal fungi influence plant community dynamics?

Stanford University, Stanford CA

Investigators

Abstract

There is a growing recognition that microbial organisms are not simply agents of disease, but play important positive roles in the everyday health of plants and animals. Much of this paradigm change has been driven by the availability of new DNA sequencing technologies that enable accurate quantification of the normally hidden microbial biodiversity. While there has been a great deal of research on the effects of the microbiome on human health, understanding the role of microbial symbiosis in structuring natural ecosystems is a current research frontier in ecology. This project will build on a long-term research program by the investigator who has used DNA based techniques to establish key patterns in the diversity and ecology of one the most common forms of plant-microbe cooperation - mycorrhizal symbiosis. Using this knowledge, the project will determine how mycorrhizal symbiosis affects the diversity, productivity, and composition of natural plant communities. Given that over 90% of all plants engage in mycorrhizal symbiosis, better understanding of these interactions will help scientists and land managers sustain robust and resilient ecosystems. In addition, this project will support development of an integrated teaching and research program to train undergraduates to use publicly available DNA sequence data and citizen science data to build species distribution models for fungi, and then publicly disseminate this information to help inspire public science participation. While molecular tools have finally enabled increasingly accurate description of the diversity and structure of mycorrhizal fungal communities, this new information has not been well integrated with existing theoretical frameworks for plant ecology. This project will use an established research system on mycorrhizal fungi in coastal California as the basis for greenhouse, field, and modeling experiments designed to identify the mechanisms and conditions under which mycorrhizal fungi strongly influence plant species coexistence at local, landscape, and regional scales. This will be carried out through a combination of greenhouse studies that manipulate the presence of mycorrhizal fungi and observe the effects on plant competition, field experiments testing the effects of mycorrhizal symbiosis for organic matter decomposition under different environmental conditions, and simulation modeling to predict the effects of mycorrhizal symbiosis on patterns of vegetation development over large spatial and temporal scales. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.