Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (8): 773-784.DOI: 10.17521/ cjpe.2015.0074

Special Issue: 碳水能量通量

• Orginal Article •     Next Articles

Environmental controls over energy, water and carbon fluxes in a plantation in Northern China

TAN Li-Ping1,2, LIU Su-Xia1,*(), MO Xing-Guo1, YANG Li-Hu1, LIN Zhong-Hui1   

  1. 1Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2014-12-29 Accepted:2015-06-30 Online:2015-08-01 Published:2015-08-17
  • Contact: Su-Xia LIU
  • About author:

    # Co-first authors

Abstract:

Aims Our objective was to examine the underline mechanisms on the driving factors of eco-hydrological processes and identify the limiting factors through both path analysis and piecewise regression. Methods The eddy covariance and meteorological data of a plantation in Chongling watershed in Northern China over the period from August 2012 to August 2013 were used for analyzing the relationships between flux indices and environmental factors. The flux indices include sensible heat, latent heat, net ecosystem production, gross ecosystem production, and ecosystem respiration, and the environmental factors include soil water content, vapor pressure deficit, air temperature, soil temperature, net radiation and photosynthetically active radiation. The direct and indirect effects of dominant and secondary factors were determined through the path analysis, and the control of secondary factors on dominant factors were analyzed using the piecewise regression. Important findings We found that the primary factor affecting sensible heat and water use efficiency was vapor pressure deficit, while latent heat and carbon fluxes were mainly controlled by radiation and temperature respectively. There also appeared significant influences from secondary variables on those fluxes. The correlations between latent heat and net radiation, ecosystem respiration and soil temperature, and water use efficiency and vapor pressure deficit were all strong when soil water content was between 0.20 m3·m-3 and 0.35 m3·m-3. The correlations between ecosystem production (both gross and net) and photosynthetically active radiation was strong when vapor pressure deficit was ≤1.0 kPa.

Key words: water and heat flux, carbon flux, environmental factors, plantation in Northern China, path analysis, piecewise regression