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应用生态学报 ›› 2018, Vol. 29 ›› Issue (6): 1822-1828.doi: 10.13287/j.1001-9332.201806.009

• 研究报告 • 上一篇    下一篇

降水变化对藏北高寒草原化草甸降水利用效率及地上生产力的影响

王志鹏1,2,张宪洲1,3,何永涛1,3*,石培礼1,3,俎佳星1,2,牛犇1,2,李猛1,2   

  1. 1中国科学院地理科学与资源研究所, 生态网络观测与模拟重点实验室, 拉萨高原生态试验站, 北京 100101;
    2中国科学院大学, 北京100049;
    3中国科学院大学资源与环境学院, 北京 100190
  • 收稿日期:2017-12-15 修回日期:2018-03-27 出版日期:2018-06-18 发布日期:2018-06-18
  • 通讯作者: E-mail: heyt@igsnrr.ac.cn
  • 基金资助:

    本研究由国家重点研发计划项目(2017YFA0604801,2016YFC0502001)、中国科学院战略性先导科技专项(XDA19050502)和西藏自治区重大科技专项(Z2016C01G01/02)资助

Effects of precipitation changes on the precipitation use efficiency and aboveground productivity of alpine steppe-meadow on northern Tibetan Plateau, China.

WANG Zhi-peng1,2, ZHANG Xian-zhou1,3, HE Yong-tao1,3*, SHI Pei-li1,3, ZU Jia-xing1,2, NIU Ben1,2, LI Meng1,2   

  1. 1Lhasa Plateau Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    2University of Chinese Academy of Sciences, Beijing 100049, China;
    3Colllege of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
  • Received:2017-12-15 Revised:2018-03-27 Online:2018-06-18 Published:2018-06-18
  • Supported by:

    This work was supported by the National Key Research and Development Project (2017YFA0604801, 2016YFC0502001), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA19050502), and the Major Science and Techno-logy Project of Xizang Autonomous Region (Z2016C01G01/02).

摘要: 降水总量、分配方式及其发生时间共同决定了青藏高原植被生长的水分条件,而降水利用效率(PUE,地上生产力与降水量的比值)是评估降水与植被生产力关系的有效指标.本研究以藏北当雄高寒草原化草甸为研究对象,利用多年生物量采样数据与同期遥感EVI植被指数建立线性模型,反演了2000—2016年地上净初级生产力(ANPP),结合同时期气象数据,以生长季降水量(GSP)表征降水总体状况,改进的降水集度指标(PCI)表征生长季降水分配,降水重心(PC)表征降水集中时间,并结合生长季均温(GST),利用结构方程分析了气候因子对当雄草地降水利用效率和地上生产力的影响.结果表明: 当雄草地ANPP主要受生长季降水影响,GSP与ANPP呈显著正相关,而GST与PUE、ANPP无显著相关关系;PCI与PUE呈显著正相关,表明降水集中分布有利于PUE增加;PCI与ANPP相关的间接系数大于直接系数,表明PCI通过PUE影响ANPP;降水集中时间(PC)变化则对PUE和ANPP没有显著影响.在青藏高原显著的气候变暖背景下,降水量和降水集度的变化都将会对藏北高寒草地的地上生产力产生重要影响.

Abstract: Total amount, distribution pattern and occurrence time of precipitation determine the water condition of alpine vegetation growth on the Tibetan Plateau, China. Precipitation use efficiency (the ratio of aboveground productivity to precipitation, PUE) is an effective indicator for the relationship between precipitation and vegetation productivity. In this study, we calculated aboveground net primary productivity (ANPP) of an alpine steppe-meadow in northern Tibetan Plateau from 2000 to 2016 based on the correlation model between long-term monitoring biomass data and enhanced vegetation index (EVI) in Damxung. Meteorological data during the same period was also analyzed. Growing season precipitation (GSP) represented the amount of precipitation, improved precipitation concentrated index (PCI) indicated their distribution pattern in the growing season, and precipitation centroid (PC) represented the time of precipitation occurrence. Structural equation model was used to explore the effects of climatic factors on PUE and ANPP, with the consideration of growing season temperature (GST). Results showed that ANPP of this alpine steppe-meadow was mainly controlled by precipitation during the growing season. GSP and ANPP showed significantly positive correlation, whereas the correlation of GST with PUE and ANPP was not significant. PCI and PUE showed significantly positive correlation, which indicated that concentrated distribution of precipitation was beneficial to the increase of PUE. Indirect coefficient between PCI and ANPP was greater than direct coefficient, indicating that PCI influenced ANPP through PUE. Changes of precipitation concentrated time did not show significant effect on PUE and ANPP. Our results suggested that under the rapid climate warming on the Tibetan Plateau, future changes of precipitation and their concentration would have important impacts on aboveground productivity of the alpine grassland.