CAREER: Illuminating how plant water-use strategies mediate ecosystem response to multiple climate extremes

Climate change is expected to bring more frequent and more severe droughts in many regions of the globe including the western United States. While important strides have been made in understanding how forests respond to individual droughts, the long-term response to multiple drought events is unclear. Thus, the response of forests to multiple climate extremes like severe drought is unknown but critical for predicting future forest health and resilience in a changing climate.

This research will combine greenhouse experiments, field measurements of mature forests, long-term forest plots, and remote-sensing data to quantify how trees and forests respond to multiple droughts. The research activities will be integrated with a wide array of education activities to achieve three goals: 1) develop undergraduate community-engaged learning projects for three community non-profit organizations, 2) integrate student learning projects with science engagement activities to broaden participation in science, technology, engineering and mathematics, and 3) train undergraduate and graduate students in research activities.

The project will establish an iterative and interactive engagement with land managers and the US Forest Service to improve forest management and resilience in a changing climate.

Climate extremes pose a fundamental threat to forest health in the coming century, but the physiological processes that govern tree responses and ecosystem fluxes remain elusive. In particular, understanding the cumulative effects of successive droughts at the tissue, tree, and ecosystem scales remains challenging due to a wide array of individual and interacting mechanisms that can either increase or decrease resilience.

This project will quantify these drivers across scales from individual trees to ecosystems using a combination of greenhouse experiments, field trait and demography measurements, long-term monitoring networks, and remote-sensing data. This research will develop and discover novel information about the physiology of plant hydraulics in response to multiple drought events, accounting for variation within individual plants, populations, and species across the southwestern United States.

The project will tackle the scaling of the non-linear physiological and demographic processes that mediate responses to climate extremes. Thus, the project will provide an advance in the ability to predict and manage forest responses to multiple droughts in a changing climate.

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.