植物生态学报 ›› 2017, Vol. 41 ›› Issue (1): 53-61.DOI: 10.17521/cjpe.2016.0019

所属专题: 中国灌丛生态系统碳储量的研究

• 研究论文 • 上一篇    下一篇

西藏雅鲁藏布江流域中段砂生槐灌丛生物量分配及碳密度

崔光帅1,2, 张林1,*(), 沈维1, 刘新圣3, 王媛韬1,2   

  1. 1中国科学院高寒生态学与生物多样性重点实验室, 中国科学院青藏高原研究所, 北京 100101
    2中国科学院大学, 北京 100049
    3九江学院旅游与国土资源学院, 江西九江 332005
  • 收稿日期:2016-01-13 接受日期:2016-05-09 出版日期:2017-01-10 发布日期:2017-01-23
  • 通讯作者: 张林
  • 作者简介:* 通信作者Author for correspondence (E-mail:sunzhiqiang1956@sina.com)
  • 基金资助:
    中国科学院战略性先导科技专项(XDA- 05050303)、国家自然科学基金(41471039)、中国科学院西部行动计划项目(KZCX2-XB3-08-02)

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

摘要:

灌丛是生态系统碳密度估算中不可或缺的部分, 其面积的增加被认为是我国陆地生态系统碳密度增加的一个重要原因, 也是生态系统碳汇研究中最不确定的一个因素。该文采用相对生长法和收获法测定了西藏雅鲁藏布江中游18个砂生槐(Sophora moorcroftiana)灌丛样点的群落生物量, 并利用实测的各器官全碳含量估算了灌丛碳密度, 主要研究结果如下: 1)灌木层植株盖度和生物量体积(盖度与高度的乘积)均能较好地预测各器官的生物量, 但盖度对地上部分各器官生物量的预测效果优于生物量体积; 2)砂生槐灌丛群落平均总生物量为5.71 Mg·hm-2, 变化范围2.32-8.96 Mg·hm-2, 灌木层是群落总生物量的主体部分, 平均为4.08 Mg·hm-2, 占群落总生物量的71.45%; 就地上、地下生物量的分配而言, 无论是灌木层还是草本层, 分配到根系的生物量更多, 平均为地上部分的1.17倍, 其在灌木层和草本层分别为2.08和0.86 Mg·hm-2; 3)灌丛平均碳密度为2.48 Mg·hm-2, 其空间分布表现为雅鲁藏布江中游西部地区较高, 东部较低。研究结果表明砂生槐生物量更多地分配到用于吸收水分和养分以及固定、支撑植物体的根系, 体现了砂生槐对雅鲁藏布江流域干旱河谷环境的适应。此外, 雅鲁藏布江中游东部地区灌丛群落碳密度低于西部, 主要与自然环境条件(东部海拔较低、气温较高、蒸散量较大, 进一步加剧干旱)和人类活动干扰有关。在未来气候变化背景下, 蒸散持续降低将有助于砂生槐灌丛碳密度的增加。

关键词: 植物相对生长法, 生物量体积, 碳密度, 冠幅, 雅鲁藏布江中游

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