EPSCoR Research Fellows: NSF: Building Radiocarbon Infrastructure and Capacity Towards a Western US Observatory of Forest Nonstructural Carbon

In long-lived trees, sugars and starches (carbohydrates) can be stored and used to support trees’ metabolism many decades later. Old carbohydrates are critical to helping trees recover from wildfires, hurricanes, drought, frost, and other extreme climate events. The age of these old carbohydrates can be estimated by measuring radiocarbon (a byproduct of nuclear bomb testing in the 1950’s and 1960’s).

However because these measurements of the age of carbohydrates are uncommon, old carbohydrates are poorly represented in global models of vegetation and climate. This proposal will support a fellowship to build new equipment and technical capacity at the University of Nevada, Las Vegas (UNLV) to measure the age of carbohydrates in long-lived trees using radiocarbon.

The PI, along with a predoctoral graduate student, will visit Northern Arizona University, during which the team will build the preparatory infrastructure to prepare samples for radiocarbon measurement. Carbohydrate age will be measured in two widely distributed and important tree species, ponderosa pine, and trembling aspen. Equipment will be transferred to UNLV to initiate a new facility to support research into carbohydrate ages, as well as additional research in southern Nevada using radiocarbon methods.

This project will train undergraduates, graduate students, and the PI to initiate a new carbohydrate research facility in southern Nevada and improve our understanding of long-lived trees and their role in the global carbon cycle.

Nonstructural carbon reserves in trees supply stored energy for later metabolism (e.g., sugars), and can be decades old. However such “old” reserves are typically absent from terrestrial vegetation models, perhaps because observational data at sufficient spatial and temporal scope are lacking. Towards quantifying the age and distribution of old carbon reserves across western forests, the PI seeks to radically enhance capacity for radiocarbon measurements at the University of Nevada, Las Vegas (UNLV).

This fellowship will thus support a visit to Northern Arizona University for mentorship to design and build the infrastructure for a radiocarbon preparatory facility. During the visit, an accompanying PhD student will gain essential training to fast-track future research. Pilot samples of two of the most widely distributed North American tree species (Pinus ponderosa and Populus tremuloides) will be collected across an elevation gradient during the fellowship period to test the new system and generate pilot data towards estimating landscape-scale carbohydrate ages in western forests.

After the visit, the system will be partially deconstructed and transported to UNLV. This proposal will thus initiate a new core facility for UNLV and the broader research community in Nevada, only 70 miles from the Nevada Test Site, where nuclear tests in the 1950’s and 60’s labeled the global biosphere with radiocarbon. The fellowship will be transformative for the PI given the research infrastructure generated.

A new core facility at UNLV will enhance institutional research and training capacity by enabling cost-effective 14C measurements. The facility will leverage broadening participation programs such the Louis Stokes Alliance program SNNA-LSAMP to train underrepresented undergraduate researchers. Training will also directly benefit a predoctoral graduate student.

Finally, students and the public will be fascinated by learning the inner workings of long-lived trees through outreach that leverages science education groups across the Southwest, including Las Vegas.

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.