The potential for climate-induced disruption of plant-microbe symbioses along altitudinal gradients

University Of New Mexico, Albuquerque NM

Investigators

Abstract

Species are moving up mountainsides as temperatures rise. As ranges move to higher altitudes, important interactions between species may be disrupted, with as yet unknown consequences. The coupled dynamics arising from species interactions can produce complex and unanticipated ecological responses to climate change. Novel species responses may feed back on the rate of climate change itself by altering processes that influence carbon cycling. Fungal symbionts of plants, such as endophytes and mycorrhizal fungi, are now well documented to influence the resilience of plants to climate change. Fungi also play critical roles in carbon cycling, by storing carbon in recalcitrant forms and decomposing organic material. Therefore, the potential for climate change to decouple plant and fungal interactions deserves careful attention. While plant movement under changing climates is easily observed, movement of fungal species is inconspicuous and little studied. This project will gauge the potential for plant-fungal symbioses to become destabilized under future climates and test the consequences of disruptions for individual plant species and carbon cycling. This project has four major components. First, the distributions of fungal symbionts colonizing plant leaves and roots will be described along replicated elevation gradients in the Rocky Mountains of Colorado, using microscopy and DNA sequencing. This work constitutes the largest altitudinal survey of fungal symbionts anywhere in the world. Second, an NSF-funded, 22-year long warming experiment will be leveraged to test, for the first time, whether fungal responses to climate warming match their distributional patterns along natural, altitudinal gradients. Third, reciprocal transplants of plants and fungi will mimic range shifts under a 3°C warmer climate and experimentally test the consequences of symbiosis decoupling. Fourth, functional assays will evaluate how disrupted symbioses affect carbon cycling. Broader Impacts: A majority of the budget is allocated to training the next generation of scientists, including students from underrepresented groups at the University of New Mexico, a majority-minority institution. K-12 outreach includes high school teacher training and curriculum development for under-served schools and symbiosis workshops in a kids nature camp and adult citizen science program supported through the Rocky Mountain Biological Laboratory.