ABSTRACT

Volatile organic compounds (VOC) are emitted into the atmosphere through natural and anthropogenic processes and play an important role in air quality and climate. One significant natural source of VOCs is from plants yet understanding how respective soils contribute to VOC emissions remains elusive. The overarching research goal of this study is to unearth microbial processes of VOC cycling below ground that describe how a changing climate may affect VOC emissions. Interdisciplinary expertise in atmospheric chemistry and ecosystem science is secured through collaborations, and necessary infrastructure is available at the University of Arizona to carry out essential field and laboratory studies. This plan provides opportunities for students to learn and engage in research and education across disciplinary boundaries and anticipates to directly impact ~100 students over the five-year project. This project was co-reviewed and co-funded by the Atmospheric Chemistry (ATC) Program in the Division of Atmosphere and Geospace Sciences and the Ecosystem Science (ES) Cluster in the Division of Environmental Biology.
Research objectives focus on identifying, separating, and constraining VOC metabolism in soil, and specifically: (1) identifying and collating microbial and root pathways that drive VOC metabolism in soil; (2) separating belowground root-microbe interactions governing VOC cycling in soil; and (3) constraining belowground VOC cycling from gene to ecosystem scales. New measurements of VOC production and consumption by microbial isolates are performed in controlled experiments in laboratory soil columns and at field scale in Biosphere 2. VOC metabolic pathways from diverse data streams are gathered in a new Microbial Volatilome Database. To distinguish root-derived contributions to net soil VOC exchange 13C stable isotope pulse labeling is implemented with online 13CVOC measurements. Finally, new soil surface and subsurface VOC data is collected in a controlled ecosystem drought experiment to advance soil VOC process models and scale belowground VOC cycling from genes to the ecosystem. Results will aid in understanding belowground drivers of VOC biosphere-atmosphere exchange that will improve projections of atmospheric impacts and biological feedbacks of VOCs.

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.

Please report errors in award information by writing to: awardsearch@nsf.gov.