关键词: 气候变化, 潜在自然植被生态系统碳储量, LPJ-GUESS模型, 主导因子, 中国

Abstract: Aims Carbon sequestration in terrestrial ecosystems is one of the important ways to slow down the rise of atmospheric CO2 concentration. Understanding the natural vegetation ecosystems carbon storage (EC) under climate change is conducive to the formulation of regional land management policies. Methods In this study, the sensitive parameters of LPJ-GUESS model are calibrated based on genetic algorithm. Using the downscale climate data-driven model, combined with Mann Kendall test, Sen's slope estimation and partial correlation analysis, the temporal and spatial pattern, trend change characteristics and climate dominant factors of China's EC from 2001 to 2100 are analyzed. Important findings The Nash-Sutcliffe efficiency coefficient and Pearson correlation coefficient of the calibrated LPJ-GUESS model in simulating EC are 0.751and 0.901 respectively, indicating that the LPJ-GUESS model can simulate China's EC well. During 2001–2020, China's EC decreased from southeast to northwest, with a total amount of 156.06 Pg C.. Vegetation, litter and soil accounted for 34.2%, 1.9% and 63.8% respectively. The EC in 2081–2100 have the same spatial heterogeneity as that in historical periods. Compared with 2001–2020, the total amount of EC at the end of this century are expected to increase by 0.51–11.16 Pg C. During 2001–2020 and 2021–2100, the growth rates of China's EC was 8.5 gC·m-2·yr-1 (p<0.05) and 3.7–21.0 gC·m-2·yr-1 (p<0.05) respectively. During 2021–2100, there was a significant increase in southeast China, inner Mongolia Plateau, Qinghai Tibet Plateau and other regions (37–44 gC·m-2·yr-1, p<0.05), while the southern Yunnan Guizhou Plateau, Liangguang hills and other regions decreased significantly (45–72 gC·m-2·yr-1, p<0.05). Considering only that climate change may reduce China's EC, compared with 2001–2020, it will decrease by 1.5–5.8% during 2081–2100. In northwest China, temperature is the dominant factor affecting EC, Affected by the degree of regional drought, the correlation between EC and precipitation increases from southeast to northwest, In high latitude and high-altitude areas, radiation is the dominant factor of EC, 47.9-56.1% of China's area，CO2 is the dominant factor of EC.

Key words: climate change, potential natural vegetation ecosystem carbon storage, LPJ-GUESS, dominant factor, China