Simulations and Analysis of Carbon Sink/Source Function of Typical Coniferous and Broadleaf Forest Ecosystems of Beijing Mountain Area in Response to Climate Change Scenarios

摘要

To investigate and evaluate the forest carbon sink/source function change based on global climate change, a process-based biogeochemical model, Biome-BGC, was used to simulate the response of typical coniferous (Pinus tabulaeformis Carr.) and broadleaf (Quercus liaotungensis Koidz.) forests in the Beijing mountain area. In our research, we validated the modeled outputs of the two species using observational data. Results showed that the outputs of the model were consistent with the annual net primary productivity (NPP) measured. The potential impacts of climate change scenarios (S1: C02 710 ppm, temperature+2 °C, precipitation -10%; S2: C02 710 ppm, temperature+2 °C, precipitation+1O%) on the two typical forest ecosystems were predicted using the BIOME-BGC model. The NPP and soil heterotrophic respiration (RH) of the two ecosystems increased significantly after the climate change, but the net ecosystem production (NEP) of the two typical forest systems decreased at the same time. Precipitation increase had positive effects on NPP and RH but negative effects on NEP. Pinus had a higher increasing rate on NPP and RH than Quercus in climate change scenarios. The productivity of Quercus was more sensitive to precipitation change. After climate change, the Pinus forest ecosystem changed from an obvious carbon sink to a slight carbon sink; Quercus changed from a slight carbon source to an obvious carbon source.