Monster Seminar JAM - Nutrient Controls over Terrestrial Carbon Storage
Dr. Alan Townsend, Institute of Arctic & Alpine Research, University of Colorado
Multiple lines of evidence suggest that terrestrial ecosystems have stored a considerable fraction of anthropogenic CO2 emissions to the atmosphere, and many future projections of atmospheric CO2 rely on continued terrestrial sinks. However, carbon storage on land is tightly coupled to the availability of several key nutrients, most notably nitrogen (N) and phosphorus (P). Thus, variations in the availability of N and P, both naturally across the terrestrial landscape, and due to human induced changes in their cycles, are likely to play a significant role in determining future carbon storage. Yet, our knowledge of these controls remains far from complete, especially for soil carbon, which comprises by far the largest actively cycling reservoir of C on land. In this talk, I will describe several recent experiments designed to test the effects of variations in N and P availability on the storage and turnover of soil carbon, in ecosystems ranging from alpine tundra to tropical rain forest. Our results suggest that at least in some instances, soil carbon reserves may be far more sensitive to changes in nutrient availability than previously thought, thereby raising questions about current projections for terrestrial carbon sinks.
Date and Time:
February 12, 2004,
11:00 am - 12:30 pm