Huang Yutao, Wang Fang, Zhang Lijuan, Zhao Junfang, Zheng Hong, Zhang Fan, Wang Nan, Gu Jiakai, Zhao Yufeng, Zhang Wenshuai
Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Harbin Normal University, Harbin, China.
State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China.
Front Plant Sci. 2023 Mar 15;14:1120064. doi: 10.3389/fpls.2023.1120064. eCollection 2023.
Changes in net ecosystem productivity (NEP) in terrestrial ecosystems in response to climate warming and land cover changes have been of great concern. In this study, we applied the normalized difference vegetation index (NDVI), average temperature, and sunshine hours to drive the C-FIX model and to simulate the regional NEP in China from 2000 to 2019. We also analyzed the spatial patterns and the spatiotemporal variation characteristics of the NEP of terrestrial ecosystems and discussed their main influencing factors. The results showed that (1) the annual average NEP of terrestrial ecosystems in China from 2000 to 2019 was 1.08 PgC, exhibiting a highly significant increasing trend with a rate of change of 0.83 PgC/10 y. The terrestrial ecosystems in China remained as carbon sinks from 2000 to 2019, and the carbon sink capacity increased significantly. The NEP of the terrestrial ecosystem increased by 65% during 2015-2019 compared to 2000-2004 (2) There was spatial differences in the NEP distribution of the terrestrial ecosystems in China from 2000-2019. Taking the line along the Daxinganling-Yin Mountains-Helan Mountains-Transverse Range as the boundary, the NEP was significantly higher in the eastern part than in the western part. Among them, the NEP was positive (carbon sink) in northeastern, central, and southern China, and negative (carbon source) in parts of northwestern China and the Tibet Autonomous Region. The spatial variation of NEP in terrestrial ecosystems increased from 2000 to 2009. The areas with a significant increase accounted for 45.85% and were mainly located in the central and southwestern regions. (3) The simulation results revealed that vegetation changes and CO concentration changes both contributed to the increase in the NEP in China, contributing 85.96% and 36.84%, respectively. The vegetation changes were the main factor causing the increase in the NEP. The main contribution of this study is to further quantify the NEP of terrestrial ecosystems in China and identify the influencing factors that caused these changes.
陆地生态系统净生态系统生产力（NEP）对气候变暖和土地覆盖变化的响应一直备受关注。在本研究中，我们应用归一化植被指数（NDVI）、平均温度和日照时数驱动C-FIX模型，模拟了2000年至2019年中国区域的NEP。我们还分析了陆地生态系统NEP的空间格局及时空变化特征，并探讨了其主要影响因素。结果表明：（1）2000年至2019年中国陆地生态系统年平均NEP为1.08 PgC，呈现极显著增加趋势，变化速率为0.83 PgC/10年。2000年至2019年中国陆地生态系统一直是碳汇，且碳汇能力显著增强。2015 - 2019年陆地生态系统的NEP相较于2000 - 2004年增加了65%。（2）2000 - 2019年中国陆地生态系统NEP分布存在空间差异。以大兴安岭 - 阴山 - 贺兰山 - 横断山脉一线为界，东部地区的NEP显著高于西部地区。其中，中国东北、中部和南部地区的NEP为正（碳汇），中国西北部分地区和西藏自治区的NEP为负（碳源）。2000年至2009年陆地生态系统NEP的空间变化增大。显著增加的区域占45.85%，主要位于中部和西南部地区。（3）模拟结果表明，植被变化和CO浓度变化均对中国NEP的增加有贡献，分别贡献了85.96%和36.84%。植被变化是导致NEP增加的主要因素。本研究的主要贡献在于进一步量化了中国陆地生态系统的NEP，并识别了导致这些变化的影响因素。
