近百年全球草地生态系统净初级生产力时空动态对气候变化的响应  

The NPP spatiotemporal variation of global grassland ecosystems in response to climate change over the past 100 years

作　　者：刚成诚[1,2,3] 王钊齐[3] 杨悦[3] 陈奕兆[3] 张艳珍[3] 李建龙[3] 程积民[1,2] 

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]南京大学生命科学学院,江苏南京210093

出　　处：《草业学报》2016年第11期1-14,共14页Acta Prataculturae Sinica

基　　金：国家自然科学基金(31602004);西北农林科技大学博士科研启动基金项目(2452015339);国家重点基础研究发展计划项目(2010CB950702)资助

摘　　要：气候变化是影响生态系统空间地理分布、结构和功能的主要因素。为了从长时间序列大空间尺度上了解气候变化对草地生态系统的影响及其反馈机制,本研究利用综合顺序分类法及分段模型分别模拟了1911-2010年间全球草地生态系统及净初级生产力(NPP)的时空动态,并通过相关性分析揭示草地NPP对不同气候因子的响应。结果表明,在过去的百年间,全球草地面积从1920s的5175.73万km^2下降到1990s的5102.16万km^2,其中冻原与高山草地类组的面积下降最多,为192.35万km^2,荒漠草地类组、典型草地类组和温带湿润草地类组的面积分别下降了14.31、34.15和70.81万km^2,而热带萨王纳类组的面积增加了238.06万km^2。在气候变化的影响下,大多数草地类组的重心均向北方移动,在北半球尤为明显。全球草地NPP从1920s的25.93Pg DW/年增加到1990s的26.67Pg DW/年。就各草地类组而言,冻原与高山草地类组、荒漠草地类组、典型草地类组、温带湿润草地类组的NPP均呈现下降趋势,分别下降了709.57、24.98、115.74和291.56Tg DW/年,而热带萨王纳类组的NPP则增加了1887.37Tg DW/年。从全球尺度来看,降水是影响草地NPP的主要气候因子。总的来说,近百年气候变化对全球草地生态系统产生了深刻的影响,尽管草地NPP呈现增加的趋势,但暖湿化的气候变化对草地生态系统的结构和空间分布产生了不利的影响。Climate change has a significant effect on the spatial distribution,structure and function of ecosystems.To understand the effects and feedback mechanisms of climate change on a large spatial and temporal scale,the distribution,shift ranges and net primary production（NPP）of grassland ecosystems across the globe from 1911 to 2010have been simulated using the Comprehensive Sequential Classification System（CSCS）and a segmentation model.Correlation analysis was also conducted to reveal the responses of grassland types to different climate variables.The results showed that the total global area of grassland ecosystems declined from5175.73×10^4 km^2 in the 1920 sto 5102.16×10^4 km^2 in the 1990 s.The largest decrease,192.35×10^4 km^2,occurred in tundra alpine steppe ecosystems.The areas of desert grassland,typical grassland and temperate humid grassland decreased by 14.31,34.15 and 70.81×10^4 km^2 respectively,while tropical savanna expanded by 238.06×10^4 km^2.Climate warming forced most grasslands to shift northwards,particularly in the northern hemisphere.Global grassland NPP increased from 25.93 Pg DW/yr in the 1920 sto 26.67 Pg DW/yr in the1990 s.In terms of each grassland type,the NPP of the tundra and alpine steppe,desert grassland,typical grassland and temperate humid grassland decreased by 709.57,24.98,115.74 and 291.56 Tg DW/yr respectively.The NPP of tropical savanna increased by 1887.37 Tg DW/yr.At the global scale,precipitation was the dominant factor affecting grassland NPP.In general,grassland ecosystems have been substantially affected by climate change over the past 100 years.Although the global grassland NPP showed an overall increasing trend,the structure and distribution of particular grassland ecosystems had been adversely affected by the warmer and wetter climate.

关 键 词：草地生态系统 综合顺序分类法(CSCS) 净初级生产力(NPP) 时空动态 分段模型 

分 类 号：S812[农业科学—草业科学]