Inaugural Charles Bullard Lectures: What Controls the Transit Time of Carbon in Ecosystems?
- Date: Mar 31, 2023
- Time: 11:00 AM - 12:00 PM (Eastern Time (US & Canada) UTC-4:00)
- Speaker: Susan Trumbore
- Location: Harvard Forest, Petersham, USA
- Room: Zoom & Harvard Forest Fisher Museum
- Host: Harvard Forest and the Harvard University Center for the Environment
- Contact: huce@environment.harvard.edu
How long does C remain in ecosystems before it is returned to the atmosphere? The answer is important because it tells us how long we might be able to manage vegetation and soils to store carbon. The major measure we have used for this is the ‘turnover time’, estimated as the inventory of carbon divided by the input or output rates. However, a single number is not sufficient to integrate the complex cascade of processes that return C fixed by photosynthesis to the atmosphere. This talk will discuss how the global isotope tracer of bomb radiocarbon can provide a means to estimate the distribution of ages of C being respired from ecosystems. Dr. Trumbore will use data from the new International Soil Radiocarbon Database to demonstrate how transit time distributions change globally, suggest how we can use this information to test global carbon cycle models, and what we can learn about managing soils to take up carbon.