摘要
本研究旨在探讨1983-2008年间印度植被净初级生产力(NPP)的时空变化格局及其与温度降水的关系。基于遥感数据和GLOPEM-CEVSA模型估算区域植被NPP,利用分段线性回归,分析了过去26年印度植被NPP的时空格局与变化特征。结果表明:(1)过去26年间印度植被年均NPP为414.29 g C·m-2·a-1,森林、农田和草地的NPP平均值分别为1002.32、485.98和631.39 g C·m-2·a-1。(2)分段线性回归结果显示,1983-2008年间,印度植被总平均NPP呈先上升后下降的趋势,趋势转折点在1996年。占印度面积比例最大的农田植被类型的平均NPP也呈先上升后下降的趋势,趋势转折点在1996年,与总平均NPP的趋势转折点一致。(3)在空间上,印度大部分地区,发生了趋势转折,趋势转折点集中在1991-2000年间,大部分地区NPP在趋势转折点前呈上升趋势,其后呈下降趋势,与区域平均NPP的变化趋势一致。(4)印度西北部干旱地区植被NPP与温度呈负相关,与降水呈正相关。喜马拉雅山南部森林NPP则与温度呈正相关。降雨量较大的印度南部地区NPP与降水呈负相关。
Net primary production（NPP） quantifies the net carbon contained by plants, which is of great importance to estimate the terrestrial carbon sink. Monitoring regional carbon storage in the form of NPP is,therefore, indispensable for improving the health state of the biosphere and system for carbon credit trading. In this study, the spatial and temporal patterns of NPP and their climatic controls in the ecosystems of India for the period of 1983- 2008 were analyzed using a remote sensing based GLOPEM- CEVSA carbon model and piecewise regression methods. Results showed that the average annual NPP of the study area from 1983 to 2008 was 414.29 g C·m-2·a-1. The mean NPP of forest, cropland and grassland were 1002.32 g C·m-2·a-1, 485.98 g C·m-2·a-1,and 631.39 g C·m-2·a-1respectively. At the national scale, a statistically insignificant positive trend of NPP was observed during 1983- 2008. However, the increasing trend in NPP was not continuous throughout the 26- year period at the national scale. There were two distinct periods with opposite trends in NPP during 1983- 2008. A significant turning point in 1996 was detected by the piecewise regression method. Firstly, NPP increased significantly from 1983 to 1996, while it then decreased from 1996 to 2008. The increase in NPP was primarily due to the enhancement of productivity over agricultural lands in the country. There are further spatial analyses supporting the concluded trend of average NPP. At the regional scale, the turning points appeared mostly in the1991-2000 period. Savanna experienced the earliest trend of change. Climate had a strong impact on NPP during the period. The correlation coefficients indicated that the inter-annual variability in NPP was primarily driven by the precipitation and temperature variability. NPP in the northwest India was negatively correlated to temperature and positively correlated to precipitation. NPP in south Himalaya forest was positively correlated to temperature.NPP in southern region of India was negatively correla
出处
《地球信息科学学报》
CSCD
北大核心
2015年第11期1355-1361,共7页
Journal of Geo-information Science
基金
国家自然科学基金项目(41371400
31400428)
曲阜师范大学博士科研启动基金项目(BSQD040000056)
关键词
植被净初级生产力
印度
遥感
分段线性回归
转折点
net primary production（NPP）
Indian
remote sensing
piecewise linear regression
turning point
