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• 干旱区盐碱土碳过程专栏 • 上一篇    下一篇

盐生荒漠净生态系统碳交换的涡度相关法和箱式法对比

马杰1,2,3,吴玉1,2,3,郑新军1,2**,唐立松1,2,王玉刚1,2   

  1. 1中国科学院新疆生态与地理研究所荒漠与绿洲国家重点实验室, 乌鲁木齐 830011; 2中国科学院阜康荒漠生态系统国家站, 新疆阜康 831505; 3中国科学院大学, 北京 100049)
  • 出版日期:2013-10-10 发布日期:2013-10-10

Net ecosystem carbon exchange in saline desert: A comparison of eddy covariance method and chamber-based method.

MA Jie1,2,3, WU Yu1,2,3, ZHENG Xin-jun1,2**, TANG Li-song1,2, WANG Yu-gang1,2   

  1. (1State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; 2Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang 831505, Xinjiang, China; 3University of Chinese Academy of Sciences, Beijing 100049, China)
  • Online:2013-10-10 Published:2013-10-10

摘要:

将叶面积指数的季节动态,与箱式法同步观测得到的同化枝净光合(呼吸)速率和土壤呼吸速率相结合,对群落碳交换进行估算,并以此验证盐生荒漠涡度相关数据的可靠性。结果表明:盐生荒漠生态系统年叶片生物量为51.30±5.56 g·m-2,其中90.45%以上来源于多枝柽柳的贡献;而整个生长季,群落叶面积指数(LAI)呈单峰形式变化,从5月30日—9月30日,LAI介于0.18~0.30,并在第197天达到最大值。涡度相关法和箱式法对群落碳交换的测定结果表明,群落碳交换存在显著的季节变化,并于7月中旬达到碳同化峰值,与LAI有显著的相关性(P<0.001)。对比发现,两种测量方法对群落碳交换日过程的测定结果有很好的一致性,但对夜间生态系统呼吸的测定,涡度相关法较箱式法存在略微的低估,引起这种低估的原因可能是夜间湍流较弱。
 

关键词: 碳稳定同位素, δ13C值, 准噶尔盆地, 土壤有机碳, 土壤无机碳

Abstract: By coupling the seasonal variation of leaf area index (LAI) with the synchronous chamber-based measurement of leaf net photosynthesis (respiration) rate and soil CO2 flux, the ecosystem carbon exchange in a saline desert was estimated, and the results were used to verify the reliability of eddy covariance data. The annual total leaf biomass of the saline desert ecosystem was 51.30±5.56 g·m-2, of which, more than 90.45% were contributed by Tamarix ramosissima. In the whole growth season, the LAI varied in single peak pattern, being 0.18-0.30 from the 30th of May to the 30th of September and peaked at the 197th day. The measurement of the carbon flux by eddy covariance method and chamber-based method showed that the net ecosystem carbon exchange had an obvious seasonal variation, which peaked in mid-July and had significant correlation with LAI (P<0.001). Through comparison, the daytime ecosystem carbon exchange from eddy covariance measurement was agreed well with that from chamberbased measurement, but the nighttime ecosystem carbon exchange from eddy covariance measurement was slightly underestimated, probably due to the weak turbulence during the night.

Key words: soil organic carbon, carbon stable isotope, Junggar Basin., soil inorganic carbon, δ13C value