地理研究 ›› 2010, Vol. 29 ›› Issue (1): 102-110.doi: 10.11821/yj2010010010

• 环境与生态 • 上一篇    下一篇

青藏高原高寒草原区域碳估测

裴志永1, 周才平2, 欧阳华2,3, 杨文斌2   

  1. 1. 中国21世纪议程管理中心,北京 100038;
    2. 中国科学院地理科学与资源研究所,北京 100101;
    3. 国际山地中心,加德满都,尼泊尔
  • 收稿日期:2009-01-14 修回日期:2009-03-02 出版日期:2010-01-20 发布日期:2010-01-20
  • 通讯作者: 周才平,男,博士,副研究员,硕士生导师。E-mail:zhoucp@igsnrr.ac.cn E-mail:zhoucp@igsnrr.ac.cn
  • 作者简介:裴志永(1976-),男,副研究员,博士。主要从事生态学、科技管理研究。 E-mail:pei@acca21.org.cn
  • 基金资助:

    国家重点基础研究发展计划(2005CB422005)和科技基础性工作专项(2006FY110200)

A carbon budget of alpine steppe area in the Tibetan Plateau

PEI Zhi-yong1, ZHOU Cai-ping2, OUYANG Hua2,3, YANG Wen-bin2   

  1. 1. The Administrative Center for China's Agenda 21, Beijing 100038, China;
    2. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    3. International Centre for Integrated Mountain Development, Kathmandu, Nepal
  • Received:2009-01-14 Revised:2009-03-02 Online:2010-01-20 Published:2010-01-20

摘要:

CASA(Carnegie-Ames-Stanford Biosphere)模型是一个表征陆地生态系统水、碳素和氮素通量随时间变化的生态系统过程模型。本研究采用MODIS遥感数据与CASA模型相结合的方法计算了青藏高原高寒草原生态系统植被净初级生产力(NPP)总量为20.57×1012g·a-1的碳。同时根据五道梁实验点上得到的经验关系估算了青藏高原高寒草原生态系统区域上的土壤碳排放(Heterotrophic respiration)总量为8.07×1012 g·a-1,因此推算得高寒草原区域内净生态系统生产力(NEP)折算成碳为12.50×1012 g·a-1

关键词: 碳估测, NPP, 呼吸, 高寒草原, 青藏高原

Abstract:

The Tibetan Plateau, the third pole of the earth, is one of the least human-disturbed regions in the world. Its outstanding topographic feature and ecological characteristics have significant effects on modern atmospheric circulation and climate, so the greenhouse gases emission and absorption are linked to climate changes at local, regional and even global scales. Also, to examine or estimate the actual magnitude of carbon uptake or release from this terrestrial ecosystem has become the central issue in global carbon cycle researches. However, relatively few studies have been reported in the literatures about the carbon contributions of the alpine grassland area on the Tibetan Plateau. In this paper, we use a mechanistically based ecological simulation model to describe and analyze the spatial pattern of terrestrial net primary productivity (NPP), carbon fluxes and net ecosystem productivity (NEP) in this alpine steppe area. The NASA-CASA (Carnegie-Ames-Stanford Biosphere) model is designed to simulate seasonal patterns in net carbon fixation and allocation, litterfall, and soil nutrient mineralization, and soil CO2 emissions. Our fundamental approach is to use CASA to estimate net primary production (NPP) in the alpine steppe area on the Tibetan Plateau. We combined MODIS data and CASA to estimate NPP, and soil carbon emissions were calculated by the regression formula obtained in the pre-study. Upon these, we estimated the carbon budget for each of the 0.05° latitude×0.05° longitude grid cells in the alpine steppe area. The potential annual net primary productivity (NPP) of this alpine steppe area is estimated to be 20.57×1012g · a-1 of carbon. The annual NPP has the distinct spatial distribution, whereas vegetation NPP decreased gradually from southeast to northwest due to the temperature and precipitation gradients. Soil carbon emission (heterotrophic respiration) is estimated to be 8.07×1012g · a-1. Net ecosystem productivity (NEP), an indicator for carbon budget, is the difference between annual net primary productivity (NPP) and annual soil respiration. Determination of net ecosystem productivity showed that the alpine steppe ecosystem acts as a distinct carbon sink (12.50×1012 g · a-1 of carbon), although this carbon reservoir is quite small.

Key words: carbon budget, NPP, respiration, alpine steppe, Tibetan Plateau