1982～1999年青藏高原植被净第一性生产力及其时空变化

基于地理信息系统技术和生态学过程模型,利用1982～1999年间NOAA-AVHRR数据(归一化植被指数,NDVI)及其相匹配的温度、降水和太阳辐射等气象数据,结合植被和土壤质地等资料,研究了青藏高原植被的净第一性生产力(NPP)及其动态变化。结果表明:青藏高原植被的总NPP为0.21PgC·a-1(1Pg=1015g),约占全国植被NPP总量的12.43%。NPP的总体分布趋势是,自东南至西北递减,这与水热条件的分布趋势一致。18年来,青藏高原植被的NPP在波动中呈上升趋势,从1982年的0.19PgC增加到1999年的0.24PgC,年平均增加速率约为1%;其中,青海省的东南部、西宁地区和西南部的部分地区,以及西藏东部的横断山区和雅鲁藏布江南部的部分地区的NPP增加显著。除10月和12月的月平均生产力呈减少趋势外,大部分植被类型的其它月份大都呈增加趋势。

Terrestrial net primary production and its spatio-temporal patterns in Qinghai-Xizang Plateau, China during 1982-1999

The terrestrial net primary production(NPP)and its spatio-temporal pattern in Qing-hai-Xizang Plateau during1982-1999were studied based on an ecological process model,using remote sensing data(NOAA-AVHRR),historical temperature,precipitation and solar radiation data,along with vegetation and soil texture information.As a result,a total mean annual NPP in the Plateau was0.21PgC(1Pg=10 15 g),occupying about 12.43%of China's total annual NPP.The NPP decreased from southeastern to northwestern part;this was coupled with the changes in precipitation and temperature.In the past18years,the terrestrial NPP in the Plateau increased from0.19PgC·a -1 in1982to0.24PgC·a -1 in1999,with an annual average increasing rate of about 1%.Regions with a significant increase in NPP appeared in southeastern Qinghai,Xining district,partial southwestern Qinghai,and eastern and partial southern Xizang.Monthly mean NPP for all months but not that for October and December showed an increasing trend through the past18years for most vegetation types.