HR: 0830h
AN: B51D-0987    [PDF]
TI: A global relationship between hetero-/autotrophic respiration and total soil surface CO$_{2}$ flux?
AU: * Bond-Lamberty, B P
EM: bpbond@wisc.edu
AF: University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706 United States
AU: Wang, C
EM: ckwang@calshp.cals.wisc.edu
AF: University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706 United States
AU: Gower, S T
EM: bpbond@wisc.edu
AF: University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706 United States
AB: Soil surface CO$_{2}$ flux (R$_{S}$) is overwhelmingly the product of respiration by roots (autotrophic respiration, R$_{A}$) and soil organisms (heterotrophic respiration, R$_{H}$), two source fluxes with different carbon sources and temperature dynamics. Many studies have attempted to partition R$_{S}$ into these two components, with highly variable results. An analysis of all published data reporting annual R$_{S}$ and the R$_{A}$/R$_{H}$ partitioning, encompassing 54 primarily forested sites, suggests that the heterotrophic and autotrophic source fluxes are each strongly (R$^{2}$ $>$ 0.8) related to total annual CO$_{2}$ flux across a wide range of ecosystems. Study biome, measurement method, mean annual temperature, and leaf habit had no significant effect on these relationships. Because belowground measurements are difficult to perform but measuring annual R$_{S}$ is straightforward and common, these relationships may provide a useful method with which to estimate the heterotrophic and autotrophic contributions to soil surface CO$_{2}$ flux for undisturbed terrestrial ecosystems.
DE: 1615 Biogeochemical processes (4805)
SC: Biogeosciences [B]
MN: 2003 Fall Meeting