Can improving predictions of soil oxygen dynamics increase understanding of greenhouse gas hotspots and hot moments?

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

The amount of oxygen in a soil affects many ecosystem processes, including the release of greenhouse gases such as nitrous oxide, methane and carbon dioxide. However, soil oxygen concentrations are rarely directly measured in research projects because they are difficult and expensive to measure accurately. Better understanding of the controls over soil oxygen could help guide land restoration projects that result in a greater removal of greenhouse gases from the atmosphere. The new technologies and approaches proposed in this project could lower the cost and enable easier measurements of soil oxygen, which could help reduce the financial burden of reducing greenhouse gas emissions in the future. This project will add to the national scientific capacity through support of four early career scientists and the interdisciplinary training of a postdoctoral student. The scientists will also enhance undergraduate research experiences. An important broader impact will be a partnership among land managers and the scientists involved to develop a continuing education program aimed at providing opportunities for citizens to engage in climate-friendly projects for the restoration of local ecosystems. Soil oxygen concentrations are usually estimated using computer models based on soil properties that are easier to measure, particularly soil water contents. But measurements made in prior research indicate that directly measured soil oxygen levels differ considerably from modeled soil oxygen levels. In fact, current computer models cannot predict the rapid changes in soil oxygen that are observed in wetlands, where the production of greenhouse gases is particularly high compared to other types of ecosystems. Mismatches between models and measurements may occur because in actual ecosystems the emission of greenhouse gases may not be constant across space and time, but likely occur under specific environmental circumstances that are particularly difficult to identify and keep track of (called hot spots or hot moments). This project will measure emissions in relation to hot spots and moments along transects running from abandoned agricultural lands into adjacent creeks at an established research site near Dayton, Ohio. Success requires high-resolution measurements of soil oxygen concentrations in space and time. This is a major challenge, but if successful, the project will critically contribute to the assessment of greenhouse gas fluxes from local ecosystems, as well as their incorporation into large-scale climate models.