Document: GRE-3-59-11

Dissolved organic carbon and nutrient modeling in terrestrial ecosystems: Integrating plant-soil physics and biogeochemistry.

ASNER, G.P.* ¹, J.C.NEFF ², W.RILEY ³ and P.A.MATSON ⁴

Univ. of Colorado, Boulder, CO 80309 USA ¹
Colorado State University, Ft. Collins, CO USA ²
Univ. of California, Berkeley, CA USA ³
Stanford University, CA USA ⁴

Abstract:
We have developed a process model, TerraFlux, of dissolved organic carbon and nutrient dynamics in near-surface (0-3 m) soils of terrestrial ecosystems. TerraFlux was developed to test hypotheses regarding the fate of dissolved elemental dynamics under varying conditions of plant physiology, biochemistry and productivity, hydrology, soil physics, and microbial biochemistry. The model employs remote sensing measurements of leaf area, productivity, and phenology to constrain estimates of organic carbon and nutrient inputs to the soil environment. TerraFlux places paramount emphasis on the transport of materials and energy within the plant-soil system by employing physically-based soil hydrological and solute transport algorithms within a multi-layer soil model. We have successfully tested the model in a variety of systems ranging from tropical and temperate forests to agriculture and semi-arid savannas. We have found that dissolved organic carbon transport and rooting distribution play a major and interactive role in determining the movement and stability of soil organic matter, which has important implications for prognostic analyses of land use and climate impacts on biogeochemical processes.

Keywords: dissolved organic carbon, DOC, dissolved organic nutrients, carbon cycle, solute transport, modeling

This abstract is being presented at: 10:30 AM in session:
CARBON STORAGE