HR: 10:20h
AN: B21H-01 INVITED     [PDF]
TI: Controls over the fractional stabilization of GPP: key processes and possible geochemical tracers
AU: * Schimel, D S
EM: schimel@ucar.edu
AF: National Center for Atmospheric Research, Climate and Global Dynamics Division 1850 Table Mesa Drive, Boulder, CO 80307 United States
AU: Still, C
EM: still@icess.ucsb.edu
AF: UC Santa Barbara, Geography Department 3611 Ellison Hall, Santa Barbara, CA 93106 United States
AU: Stephens, B B
EM: stephens@ucar.edu
AF: National Center for Atmospheric Research, Atmospheric Technology Division 1850 Table Mesa Drive, Boulder, CO 80307 United States
AB: It is often assumed that there is a relationship between biological productivity and carbon storage, but high rates of sequestration can be documented in areas with widely different levels of primary productivity. A number of analyses have shown that estimated global sinks cannot be due only to increases in productivity, because the required increases are too large for known mechanisms. Changes in the rate of storage must also be occurring. Both autotrophic and heterotrophic processes can affect the stabilization of plant material. Likely candidates include high allocation to wood and/or decay resistant organic matter, and increases in residence time of sedimentary organic matter in areas of enhanced erosion. Both of these processes are linked to changes in disturbance regime. In this talk we review mechanisms affecting the fraction of productivity stabilized, the ratio of NBP to GPP, and discuss the utility of this ratio as a tracer. We suggest that because of the chemical and isotopic composition of stable plant material, large-scale geochemical tracers of NBP/GPP may exist.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2003 Fall Meeting