Quantitative assessment of the carbon dioxide absorption capacity of vegetation in China, 2000-2020.

CO2 is the main cause of the dramatic increase in greenhouse gases, posing a serious threat to human systems and ecosystems. Most existing studies focus on estimating carbon emissions and carbon sequestration, and there are relatively few studies on the quantitative analysis of CO2 uptake by vegetation. Therefore, this paper constructed a Carbon Uptake Index (CUI) model based on the carbon estimation model and the Vegetation Carbon sequestration (VCs) model. It was used to estimate the distributional characteristics of carbon absorption in China from 2000 to 2020. Then, the inter-annual variation and spatial aggregation characteristics of carbon absorption were analyzed using linear regression models and spatial autocorrelation, respectively. The results show that from 2000 to 2020, China's carbon uptake as a whole is in an absorptive state, with significant spatial correlation. Inter-annual variability shows an overall decreasing trend, dominated by a slight decreasing trend. The spatial characteristics of carbon absorption are mainly aggregated, with low-low aggregation in the western part of China and high-high aggregation in the southern part. The results of this paper will provide a reasonable reference for China to achieve carbon peak and carbon neutrality.