Chin J Plan Ecolo ›› 2017, Vol. 41 ›› Issue (1): 53-61.DOI: 10.17521/cjpe.2016.0019

• Research Articles • Previous Articles     Next Articles

Biomass allocation and carbon density of Sophora moorcroftiana shrublands in the middle reaches of Yarlung Zangbo River, Xizang, China

Guang-Shuai CUI1,2, Lin ZHANG1,*(), Wei SHEN1, Xin-Sheng LIU3, Yuan-Tao WANG1,2   

  1. 1Key Laboratory of Alpine Ecology and Biodiversity of Chinese Academy of Sciences, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
    and
    3College of Tourism and Territorial Resources, Jiujiang University, Jiujiang, Jiangxi 332005, China
  • Received:2016-01-13 Accepted:2016-05-09 Online:2017-01-10 Published:2017-01-23
  • Contact: Lin ZHANG
  • About author:

    KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

Abstract:

Aims The expansion of shrublands is considered as one of the key reasons leading to the increase of carbon density in terrestrial ecosystems in China. In the present study, our aims were to explore the biomass allocation and carbon density of Sophora moorcroftiana shrublands in Xizang.
Methods We sampled the biomass of S. moorcroftiana shrubs from 18 sites in the middle reaches of Yarlung Zangbo River, Xizang. Using concentrations of different organs, we estimated the carbon density of different layers in S. moorcroftiana shrublands.
Important findings The plant cover rather than biomass volume (the product of cover and height) provided the best fit for aboveground biomass. The average of the total biomass was 5.71 Mg·hm-2, ranging from 2.32 to 8.96 Mg·hm-2. The average biomass of shrub layer, the main component of shrub ecosystem, was 4.08 Mg·hm-2, accounting for 71% of the total biomass. The belowground biomass of shrub and herb layers was 2.08 and 0.86 Mg·hm-2, respectively, which was higher than the corresponding aboveground biomass. The average biomass carbon density was 2.48 Mg·hm-2. Shrub vegetation in the eastern part of the middle reaches has lower carbon density than that in the western part. The relatively high biomass allocation to roots to increase water and nutrient undertake as well as physical support for plants is an important strategy of S. moorcroftiana to cope with the arid environment on the Qinghai-Xizang Plateau. Moreover, the lower carbon density in the eastern part of the middle reaches might be due to the dry environment resulted from high temperature and evapotranspiration and enhanced human activities at low altitudes. The continuous decrease of evapotranspiration under scenarios of future climate change may lead to increase in carbon density in S. moorcroftiana shrublands.

Key words: plant allometry, biomass volume, carbon density, crown breadth, middle reaches of Yarlung Zangbo River