中国植被碳源/汇时空演变特征及其驱动因素

植被生态系统对植被碳汇至关重要，是实现中国“碳中和”目标的重要路径之一。选择1981—2019年全球逐日NEP模拟数据产品，对1981—2019年中国植被碳源/汇时空演变进行分析，确定气候变化和人类活动对植被碳源/汇的影响区域，并量化生态修复治理工程对植被碳汇的成效。(1)通过使用BFAST模型监测NEP年际突变范围，确定2001年为时间断点，对比分析1981—2001年与2001—2019年NEP时空变化特征及驱动因素。(2)1981—2001年段植被碳汇大范围呈现递减趋势。2001—2019年，中国整体植被碳汇增加，尤其是北部地区NEP增长趋势显著。(3)1981—2001年中国北部地区植被固碳能力下降，受降水、辐射影响为主。2001—2019年，大部分地区NEP变化与降水相关性显著。(4)1981—2001年人类活动导致植被碳源/汇变化占总面积的4%,主要分布于东北地区和西南地区。2001—2019年中国植被碳源/汇变化由人类活动影响占比提高至26.23%,其中植被固碳能力提升占比25.22%。气候变化负向影响植被固碳能力较于1981—2001年减少约30%。说明人类活动在一定程...

Spatio-temporal evolution characteristics and driving factors analysis of vegetation carbon sources/sinks in China

Vegetation ecosystems are crucial for vegetation carbon sinks and represent an important path towards achieving China''s carbon neutrality goal. In this study, global daily NEP (Net Ecosystem Productivity, NEP) simulation data products from 1981 to 2019 were selected to analyze the spatial and temporal evolution of vegetation carbon sources/sinks in China. The impacts of climate change and human activities on vegetation carbon sources/sinks were determined, and the effectiveness of ecological restoration and control projects on vegetation carbon sinks was quantified. The BFAST model was used to monitor the annual range of NEP inter-annual changes and to identify 2001 as the time breakpoint. The temporal and spatial characteristics and driving factors of NEP changes between 1981 and 2001 and between 2001 and 2019 were analyzed and compared. From 1981 to 2001, vegetation carbon sinks showed a widespread decreasing trend, with an NEP average of 17.59gC/m². However, from 2001 to 2019, the growth trend of vegetation carbon sinks in northern China changed significantly, with a NEP average of 35.64gC/m². The changes in vegetation carbon sources/sinks in northern China between 1981 and 2001 were mainly due to the influence of climatic factors, which led to a weakening of vegetation carbon fixation capacity. The North China and Northwest regions were mainly affected by precipitation, while the Northeast region was mainly affected by radiation changes. From 2001 to 2019, most of the changes in the NEP were influenced by precipitation and radiation. However, in the Sichuan and Chongqing regions, the impact of temperature and radiation on vegetation carbon fixation capacity was more significant. Human activities caused a change of 4% in vegetation carbon sources/sinks between 1981 and 2001, mainly distributed in the Northeast and Southwest regions. From 2001 to 2019, the proportion of vegetation carbon sources/sinks affected by human activities increased to 26.23%, of which the proportion of enhanced vegetation carbon fixation capacity accounted for 25.22%. The negative impact of climate change on vegetation carbon fixation capacity decreased by about 30% compared to that from 1981 to 2001, indicating that human activities reduced the negative impact of climate change on vegetation ecosystems to a certain extent. The net carbon storage value in 2019 showed significant growth compared to that in 2001, and the economic efficiency of ecological restoration and control investment was positively correlated with most ecological regions. In addition, vegetation carbon sinks in northern China were effectively improved. Therefore, in order to address climate change and protect the ecological environment, it is necessary to actively promote ecological restoration and control investment to achieve sustainable development of the economy, society, and environment.