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干旱区地理 ›› 2016, Vol. 39 ›› Issue (4): 809-816.

• 生态与环境 • 上一篇    下一篇

张掖湿地CO2通量变化特征及光能利用率分析

蒋国庆1,2,3, 王玉洁4,5, 孙睿1,2,3, 张蕾1,2,3, 刘绍民1,2, 徐自为1,2, 张强1,2,3   

  1. 1 遥感科学国家重点实验室北京师范大学/中国科学院遥感应用研究所, 北京 100875;
    2 北京师范大学地理学与遥感科学学院, 北京 100875;
    3 环境遥感与数字城市北京市重点实验室, 北京 100875;
    4 西北区域气候中心, 甘肃 兰州 730020;
    5 南京大学大气科学学院, 江苏 南京 210023
  • 收稿日期:2016-03-02 修回日期:2016-05-12 出版日期:2016-07-25
  • 通讯作者: 孙睿,男,博士生导师.Email:sunrui@bnu.edu.cn
  • 作者简介:蒋国庆(1989-),女,硕士研究生,山东莱芜人,研究方向:资源与环境遥感.Email:guoqing_jiang@sina.cn
  • 基金资助:

    国家自然科学基金(41471349);国家科技支撑计划项目(2013BAC03B02);中央高校基本科研业务费专项(2014kJJCA02)

Dynamics of CO2 flux and analysis of light use efficiency over a wetland in Zhangye,China

JIANG Guo-qing1,2,3, WANG Yu-jie4,5, SUN Rui1,2,3, ZHANG Lei1,2,3, LIU Shao-min1,2, XU Zi-wei1,2, ZHANG Qiang1,2,3   

  1. 1 State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal University and the Institute of Remote Sensing Applications, CAS, Beijing 100875, China;
    2 School of geography and Remote Sensing Sciences, Beijing Normal University, Beijing 100875, China;
    3 Beijing Key Lab for Remote Sensing of Environment and Digital Cities, Beijing 100875, China;
    4 Northwest Regional Climate Center, Lanzhou 730020, Gansu, China;
    5 School of Atmospheric Sciences, Nanjing University, Nanjing 210023, Jiangsu, China
  • Received:2016-03-02 Revised:2016-05-12 Online:2016-07-25

摘要: 湿地生态系统储存着大量的碳,在陆地碳循环中扮演着很重要的角色。同时,湿地生态系统本身比较脆弱,特别是干旱地区湿地生态系统,对气候变化非常敏感,容易受到环境因素的影响而改变原有的碳循环模式。干旱区湿地碳循环规律研究不但有助于评估干旱区湿地生态效益,也有助于分析其对气候变化的响应。通过对甘肃省张掖湿地CO2通量的观测(2012年6月~2014年8月),分析了湿地生态系统CO2通量的季节变化特征,并结合遥感数据,估算了湿地生态系统的光能利用率,分析了环境因子对CO2通量和光能利用率的影响。结果表明,湿地CO2通量的季节变化特征明显,两整年GPP平均值为1.06 kg C m-2·a-1,NEE平均值为-0.40 kg C m-2·a-1,为明显的碳汇。空气温度和土壤温度与夜间生态系统呼吸都呈显著的指数关系,太阳辐射与湿地白天CO2通量呈负相关,并且随季节不同,相关性差异较大。结合遥感数据计算得到的光能利用率最大值为1.51 g C·MJ-1,生长季平均光能利用率为1.07 g C·MJ-1。光能利用率与温度有一定的相关性,随温度升高,光能利用率呈现增大趋势。

关键词: 湿地, 涡度相关, CO2通量, 温度, 辐射, 光能利用率, 遥感

Abstract: Wetland ecosystem stores a large amount of carbon in the soil and plays an important role in the terrestrial carbon cycle. Meanwhile,wetland ecosystem,especially wetland in the arid area,is sensitive to climate change and very fragile. Its carbon cycle is easily influenced by environmental factors and human activity. It is significant to study carbon cycle of wetland ecosystem in the arid area. With CO2 flux observation over a Phragmites-dominated wetland in Zhangye oasis,Gansu province,northwest China(from June,2012 to August,2014), the seasonal change of CO2 flux and environmental impact factors of the wetland were analyzed first. And combining with fraction of absorbed photosynthetically active radiation(FPAR) from MODIS remote sensing data, light use efficiency(LUE) of the wetland was also estimated. The results showed that there was a distinct seasonal variation of CO2 flux. The mean gross primary productivity(GPP) over two years was 1.06 kg C·m-2·a-1,and the mean net ecosystem exchange(NEE) over two years was -0.40 kg C·m-2·a-1. The wetland was apparently a carbon sink. The night-time ecosystem respiration exponentially increased with air temperature and soil temperature, while there was a negative correlation between daytime CO2 flux values and incident solar radiation,and the relation changed seasonally. The maximum value of LUE was 1.51 g C·MJ-1 and the average LUE during the growing seasons was 1.07 g C·MJ-1. LUE was generally related with air temperature,and the value of LUE increased with temperature increasing,which means the higher conversion efficiency of solar energy to dry matter when the air temperature is close to the optimum temperature for vegetation growth.

Key words: wetland, eddy covariance, CO2 flux, temperature, radiation, light use efficiency, remote sensing

中图分类号: 

  • Q14