A Simulation Study of Coupled Feedback Mechanism between Physical and Biogeochemical Processes at the Surface
地表面物理过程与生物地球化学过程耦合反馈机理的模拟研究

The mechanism and approach of intercoupling between physical and biogeochemical proesses at land surface are investigated by the use of an atmosphere-vegetation interaction model (AVIM). The basis for the feedback mechanism is that on seasonal and interannual scales, the physical exchange processes of materials and energy between plant and abiotic environment and physiological processes influence plant growth, leading to significant change in macromorphology of plant, and then the changes in surface dynamical parameters, in turn, affect physical exchange processes between vegetation, atmosphere and soil. By using the AVIM to semi-arid steppe in Inner-Mongolia, China, net primary production of grass ecosystem, exchanges of CO 2, sensible and latent heat fluxes between vegetation and the atmosphere are simulated. The results show that the seasonal and interannual variations of NPP are significantly affected by the climate; meanwhile, the budget and partitioning of energy at the surface are also affected by the growth of steppe.