Journal of Integrative Agriculture ›› 2017, Vol. 16 ›› Issue (10): 2323-2336.DOI: 10.1016/S2095-3119(16)61614-3

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  • 收稿日期:2016-12-30 出版日期:2017-10-20 发布日期:2017-09-30

Modeling the regional grazing impact on vegetation carbon sequestration ability in Temperate Eurasian Steppe

CHEN Yi-zhao1, 2, SUN Zheng-guo3, QIN Zhi-hao4, Pavel Propastin5, 6, WANG Wei7, LI Jian-long2, RUAN Hong-hua1   

  1. 1 Joint Innovation Center for Modern Forestry Studies, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, P.R.China
    2 School of Life Science, Nanjing University, Nanjing 210093, P.R.China
    3 College of Prataculture Science, Nanjing Agricultural University, Nanjing 210095, P.R.China
    4 Institute of Agro-resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
    5  Institute of Geography, Georg-August University Göttingen, Göttingen 37077, Germany
    6 Department of Bioclimatology, Büsgen-Institute, Georg-August University Göttingen, Göttingen 37077, Germany
    7 College of Forestry, Nanjing Forestry University, Nanjing 210037, P.R.China
  • Received:2016-12-30 Online:2017-10-20 Published:2017-09-30
  • Contact: Correspondence SUN Zheng-guo, Tel/Fax: +86-25-84395284, E-mail: sunzg@njau.edu.cn
  • About author:CHEN Yi-zhao, E-mail: chenyzvest@gmail.com;
  • Supported by:

    This work is supported by the National Key Research and Development Program of China (2016YFC0500202), the Natural Science Foundation of Jiangsu Province, China (BK20140413), the Asia-Pacific Network (APN) Global Change Fund Project (ARCP2013-16NMY-Li) and the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions, China.

Abstract: Anthropogenic activities profoundly influence carbon sequestration in the Eurasian Steppe.  In particular, grazing has been identified as having a major effect on carbon sequestration.  However, the extent to which grazing affects regional patterns or carbon sequestration is unknown.  In this study, we evaluated the impact of regional grazing on grassland carbon sequestration using the Boreal Ecosystem Productivity Simulator (BEPS) and the Shiyomi grazing model.  Model performances were validated against the results from field measurements and eddy covariance (EC) sites.  Model outputs showed that in 2008, the regional net primary productivity (NPP) was 79.5 g C m–2, and the net ecosystem productivity (NEP) was –6.5 g C m–2, characterizing the region as a weak carbon source.  The Mongol Steppe (MS) was identified as a carbon sink, whereas the Kazakh Steppe (KS) was either carbon neutral or a weak carbon source.  The spatial patterns of grazing density are divergent between the MS and the KS.  In the MS, livestock was mainly distributed in China with relatively good management, while in the KS livestock was mainly concentrated in the southern countries (especially Uzbekistan and Turkmenistan) with harsh environments and poor management.  The consumption percentages of NPP in Turkmenistan, Tajikistan and Uzbekistan were 5.3, 3.3 and 1.2%, respectively, whereas the percentages in other countries were lower than 1%.  Correspondingly, grazing consumption contributed to the carbon sources of Turkmenistan, Tajikistan and Uzbekistan by 11.6, 6.3 and 4.3%, respectively, while it weakened the carbon sink in Inner Mongolia, China and Mongolia by 1.6 and 0.5%.  This regional pattern should be affected by different sub-regional characteristics, e.g., the continuous degradation of grassland in the southern part of the KS and the restoration of grassland in Inner Mongolia, China.

Key words: Temperate Eurasian Steppe ,  terrestrial modeling ,  carbon sequestration ability ,  grazing activity ,  regional evaluation