Developing a New Geospatial Approach for Rangeland Carbon Monitoring

Abstract:

Over 25% of the global land surface, and 33% of land in the United States, is used for the grazing of livestock. These grasslands have an enormous potential to sequester carbon dioxide (CO2) from the atmosphere and to provide long-term carbon storage in the soil. Various management practices such as plant restoration, optimizing water use efficiency, and minimizing the duration of grazing disturbances during critical periods of vegetation growth can help to enhance the capacity of a landscape to capture and store carbon. Baseline assessments and monitoring of grassland carbon storage often focus on in situ field measurements of soil carbon. The rates of carbon exchange (i.e., fluxes) between the ecosystem and the atmosphere can also be measured to identify how much CO2 is entering and existing in a grassland system over a duration of time, though this is less common. Both in situ measurements of soil carbon and ecosystem carbon flux are time consuming and expensive to collect, especially over large regions. As a result, rangeland carbon stocks and change in response to management have not been well quantified. This project is developing a new Rangeland Carbon Tracking and Management Tool (RCTM) for monitoring changes in rangeland soil carbon. The RCTM incorporates information from satellite remote sensing within mathematical models of vegetation carbon productivity to provide weekly estimates of change in ecosystem CO2 uptake and loss (via respiration) and changes in soil carbon status at a 30-m spatial resolution. Here we provide a case study of the RCTM applied to landscapes having differing rangeland management and climatic conditions within the northern Rocky Mountain region of the U.S. This tool is versatile and can be applied using Google Earth Engine to other grassland regions.