He Honglin, Wang Shaoqiang, Zhang Li, Wang Junbang, Ren Xiaoli, Zhou Lei, Piao Shilong, Yan Hao, Ju Weimin, Gu Fengxue, Yu Shiyong, Yang Yuanhe, Wang Miaomiao, Niu Zhongen, Ge Rong, Yan Huimin, Huang Mei, Zhou Guoyi, Bai Yongfei, Xie Zongqiang, Tang Zhiyao, Wu Bingfang, Zhang Leiming, He Nianpeng, Wang Qiufeng, Yu Guirui
Synthesis Research Center of China's Ecosystem Research Network, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China.
Natl Sci Rev. 2019 May;6(3):505-514. doi: 10.1093/nsr/nwz021. Epub 2019 Feb 17.
The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes. Over the past decade, China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming. However, the changes in the trends of terrestrial net ecosystem production (NEP) in China under climate changes are not well documented. Here, we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982-2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country. Our results revealed a decadal-scale shift in NEP from a downtrend of -5.95 Tg C/yr (reduced sink) during 1982-2000 to an uptrend of 14.22 Tg C/yr (enhanced sink) during 2000-10. This shift was essentially induced by the strengthened summer monsoon, which stimulated carbon uptake, and the warming hiatus, which lessened the decrease in the NEP trend. Compared to the contribution of 56.3% by the climate effect, atmospheric CO concentration and nitrogen deposition had relatively small contributions (8.6 and 11.3%, respectively) to the shift. In conclusion, within the context of the global-warming hiatus, the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration. Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades, but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas.
中国陆地生态系统的碳收支与气候变化密切相关。在过去十年中，中国经历了显著的气候变化，其特征是夏季风增强和变暖减缓。然而，气候变化下中国陆地生态系统净生产力（NEP）趋势的变化尚未得到充分记录。在此，我们使用三个生态系统模型来模拟1982 - 2010年期间中国NEP的时空变化，并量化增强的夏季风和变暖停滞对该国四个不同气候区域NEP变化的贡献。我们的结果显示，NEP在年代际尺度上发生了转变，从1982 - 2000年期间-5.95 Tg C/yr的下降趋势（汇减少）转变为2000 - 2010年期间14.22 Tg C/yr的上升趋势（汇增强）。这种转变主要是由增强的夏季风刺激碳吸收以及变暖停滞减少NEP趋势下降所导致的。与气候效应56.3%的贡献相比，大气CO浓度和氮沉降对这种转变的贡献相对较小（分别为8.6%和11.3%）。总之，在全球变暖停滞的背景下，夏季风增强是一个关键的气候因素，由于光合作用和呼吸作用的不对称响应，它增强了中国的碳吸收。我们的研究不仅揭示了近几十年来中国生态系统碳固存的转变，还为理解其他季风区的生态系统碳动态提供了一些见解。
