植物生态学报 ›› 2016, Vol. 40 ›› Issue (12): 1219-1229.DOI: 10.17521/cjpe.2016.0186

• 研究论文 •    下一篇

不同幅度的实验增温对藏北高寒草甸净生态系统碳交换的影响

朱军涛1, 陈宁1, 张扬建1,2,3,*(), 刘瑶杰1   

  1. 1拉萨高原生态试验站, 生态系统网络观测与模拟重点实验室, 中国科学院地理科学与资源研究所, 北京 100101
    2中国科学院青藏高原地球科学卓越创新中心, 北京 100101
    3中国科学院大学, 北京 100049
  • 出版日期:2016-12-10 发布日期:2016-12-30
  • 通讯作者: 张扬建

Effects of experimental warming on net ecosystem CO2 exchange in Northern Xizang alpine meadow

Jun-Tao ZHU1, Ning CHEN1, Yang-Jian ZHANG1,2,3,*(), Yao-Jie LIU1   

  1. 1Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China

    2Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China

    3University of Chinese Academy of Sciences, Beijing 100049, China
  • Online:2016-12-10 Published:2016-12-30
  • Contact: Yang-Jian ZHANG

摘要:

全球气候变暖将对陆地生态系统(尤其是高寒草甸生态系统)碳循环产生深远影响。该研究依托中国科学院地理科学与资源研究所藏北高原草地生态系统研究站(那曲站), 设置不同增温幅度实验, 模拟未来2 ℃增温和4 ℃增温的情景, 探究不同增温幅度对青藏高原高寒草甸净生态系统碳交换(NEE)的影响。研究结果显示: 1)在2015年生长季(6-9月), 不增温和2 ℃增温处理下NEE小于0, 总体表现为碳汇, 而4 ℃增温处理下NEE大于0, 总体表现为碳源; 2)在生长季的6月、8月及整个生长季, 与不增温相比, 4 ℃增温处理显著提高了NEE, 而2 ℃增温处理没有显著改变NEE; 7月, 2 ℃和4 ℃增温处理均显著提高了NEE; 3)在半干旱的高寒草甸生态系统, 土壤水分是决定NEE的关键因素, 增温通过降低土壤水分而导致高寒草甸生态系统碳汇能力下降。该研究可为青藏高原高寒草甸生态系统应对未来气候变化提供基础数据和理论依据。

关键词: 气候变暖, 高寒草甸, 净生态系统碳交换, 碳收支, 藏北高原

Abstract: AimsGlobal warming could have profound effects on ecosystem carbon (C) fluxes in alpine ecosystems. The aim of our study is to examine the effects of gradient warming on net ecosystem carbon exchange (NEE).MethodsIn the Northern Tibetan Grassland Ecosystem Research Station (Nagqu station), Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, we conducted various levels of temperature increasing experiments (i.e., 2 °C and 4 °C increments). The warming was achieved using open-top chambers (OTCs). In total, there were three levels of temperature treatments (control, 2 °C and 4 °C increment), and four replicates for each treatment. The ecosystem NEE was monitored every five days during the growing season in 2015.Important findings Our findings highlight the importance of soil moisture in mediating the responses of NEE to climatic warming in alpine meadow ecosystem. The 4 °C warming significantly stimulated NEE,except for July measurements. The 2 °C warming had no effects on NEE during the growing season. Compared to the 2 °C warming, the 4 °C warming significantly stimulated NEE. The results showed that our targeted ecosystem acts as a carbon sink under 2 °C warming, whereas will act as a net carbon source under 4 °C warming in the future. This study provides basic data and theoretical basis for evaluating the alpine ecosystem’s responses to climate change.

Key words: global warming, alpine meadow, net ecosystem carbon exchange, carbon budget, Northern Xizang plateau