[B-BC03] Earth and Planetary Science Frontiers for Life and Global Environment

[BBC03-P06] China’s terrestrial ecosystem carbon balance during the 20^th century: An analysis with a process-based biogeochemistry model

*Yanyu Lu¹, Wei Sun², Dongyan He¹, Hanqing Deng¹, Hong Tian¹, Biwen Wu¹ (1.Anhui Climate Center, Anhui Meteorological Administration, 2.Anhui Public Meteorological Service Center, Anhui Meteorological Administration)

Keywords:China, Terrestrial Ecosystem Model, Carbon cycle, Climate change, Land use, Hu Huanyong line

China’s terrestrial ecosystems play a pronounced role in the global carbon cycle. Here we combine spatially-explicit information on vegetation, soil, topography, climate and land use change with a process-based biogeochemistry model to quantify the responses of terrestrial carbon cycle in China during the 20^th century. We find that that the regional soil thermal and moisture regimes have dramatically changed. Specifically, evapotranspiration increased due to rising temperature and soils were drying in the last two decades of the 20^th century. At a century scale, China’s terrestrial ecosystems have acted as a carbon sink averaging at 0.09 Pg C yr^-1, with large inter-annual and decadal variabilities. The regional sink has been enhanced due to the rising temperature and CO₂ concentration, with a slight increase trend in carbon sink strength along with the enhanced net primary production in the century. Meanwhile, the heterotrophic respiration increased in response to warming. The spatial and temporal variabilities of carbon balance in China are due to multiple controlling factors including temperature and precipitation and changing atmospheric CO₂ concentrations. Land-use changes including reforestation and afforestation during the late 20^th century partially contributed to the increase in carbon sink at the national scale.