Chin J Plant Ecol ›› 2018, Vol. 42 ›› Issue (3): 372-381.DOI: 10.17521/cjpe.2016.0049

Special Issue: 碳循环

• Research Articles • Previous Articles     Next Articles

Effects of fencing on ecosystem carbon exchange at meadow steppe in the northern slope of the Tianshan Mountains

HU Yi1,2,ZHU Xin-Ping1,2,JIA Hong-Tao1,2,*(),HAN Dong-Liang1,2,HU Bao-An1,2,LI Dian-Peng1   

  1. 1 College of Grassland and Environmental Sciences, Xinjiang Agricultural University, ürümqi 830052, China;
    2 Xinjiang Key Laboratory of Soil and Plant Ecological Processes, ürümqi 830052, China;
  • Online:2018-03-20 Published:2017-06-16
  • Contact: Hong-Tao JIA ORCID:0000-0002-8527-0581
  • Supported by:
    Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA05050405);the National Natural Science Foundation of China(31560171);Innovation Plan of Postgraduate Education in Xinjiang Uygur Autonomous region of China.(XJGRI2014084)


Aims The carbon exchange between ecosystems and the atmosphere and its response to environmental factors is the focus of current research. The aim of this study was to examine the effects of fencing on ecosystem carbon exchange at meadow steppe in the northern slope of Tianshan Mountains.

Methods The static box method with a LI-840 CO2/H2O infrared analyzer was used to evaluate daily and seasonal changes of ecosystem carbon exchange and their relationship with environmental factors in the inside fence and outside fence after 9 years fencing.

Important findings We found the ecosystem carbon exchange inside the fence was significantly (p < 0.05) higher than that in outside the fence. The ecosystem carbon exchange had obvious daily and seasonal variation both in inside and outside the fence, which showed a unimodal curve during the plant growing season. The minimum net ecosystem CO2 exchange (NEE) in the inside and outside of the fences were -7.62 and -6.63 μmol·m-2·s-1, respectively; the maximum ecosystem respiration (ER) were 8.55 and 7.04 μmol·m-2·s-1, respectively; and the maximum gross ecosystem productivity (GEP) were -14.66 and -13.89 μmol·m-2·s-1, respectively. Due to the protection of fence, the vegetation in the fence was flourished with higher photosynthesis, and thus resulted in lower NEE. Meanwhile, organic carbon input enhanced ecosystem respiration. Besides, the ecosystem carbon exchange significantly correlated with the air temperature and soil temperature of 0 to 10 cm depth, and the correlation with the air temperature was higher than soil temperature of 0 to 10 cm depth. Also, the correlation in the inside of the fence was higher than that in the outside of the fence. Ecosystem carbon exchange had correlation with soil water content, but the correlation was slightly lower than that with soil temperature.

Key words: fencing, meadow steppe, ecosystem carbon exchange