CAREER: Spatiotemporal Dynamics of Plant-Mycorrhizal Fungal Symbioses at Continental Scale

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

Ecological communities function as a network of interactions among individual organisms. The most widespread of these interactions is that among plants and mycorrhizal fungi in the soil. In these interactions, mycorrhizal fungi provide water and nutrients for plants, increasing plant growth by up to 50%. However, interactions among plants and mycorrhizal fungi are changing as global change alters the spatial distribution of plants and fungi as well as the times of the year in which they are active. This research will investigate how much plant and mycorrhizal fungi interactions vary over time using current and historical records of mycorrhizal fungal locations. The research will also mimic the effects of global change on mycorrhizal fungal distributions by observing how northern plants grow with fungi from southern locations. Finally, undergraduate students will create predictive models of how forests across the eastern United States may be affected by disrupted interactions among plants and mycorrhizal fungi. This CAREER proposal is highly integrated with an educational program where undergraduate students will receive hands on experience in designing, implementing, analyzing, and modeling research at all stages of the project, preparing a cohort of undergraduate students for the scientific workforce. The most widespread and biogeochemically impactful of symbiosis on Earth is the nutritional and protective symbioses between plants and mycorrhizal fungi. Yet, the stability of plant-mycorrhizal fungal interactions in the Anthropocene is far from certain. If plant and mycorrhizal fungal symbiont partners react divergently to shifting climates, previously beneficial interactions may be decoupled in space and across time creating no-analog biological communities with unknown functions. This research will address the potential for plant-mycorrhizal fungal symbiosis decoupling by examining the spatial variation in mycorrhizal fungal associations across ten foundational tree species ranges at 20 sites across the eastern United States, and short and long-term temporal variation in plant-mycorrhizal fungal associations at each of those sites and at continental scales. Through common gardens and newly developed, inquiry driven, course-based undergraduate research experiences (CURES), undergraduate students will test the outcome of symbiosis when plants are grown with mycorrhizal fungi from the leading, center, or trailing edges of their ranges. The project will then create predictive ecological forecasting models of the biogeography and function of plant-mycorrhizal fungal associations under current and future climate scenarios. Undergraduate training is at the heart of this project, with highly integrative course-based, field-based, and laboratory-based research as well as pedagogical training experiences for a cohort of students. 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.