摘要
利用GIMMS和MODIS两种遥感数据,分析了1982～2008年东北冻土区植被生长季平均NDVI的时空特征,并探讨不同类型冻土区和不同植被类型归一化差值植被指数(NDVI)对气候变化和CO2体积分数增加的响应.研究表明,不同冻土类型区植被生长季NDVI均值从大到小依次为:连续多年冻土区>大片多年冻土区>季节性冻土区>岛状多年冻土区.东北冻土区不同植被类型生长季平均NDVI值由大到小依次为:森林>灌丛>沼泽>农田>草地,其中森林植被生长季平均NDVI值为0.61,草地为0.46.过去27年间,东北冻土区植被生长季平均NDVI年际变化曲线可分为3个变化阶段:①1982～1990年,小幅上升阶段;②1990～2000年,缓慢下降阶段;③2000～2008年,明显上升阶段.1982～2008年期间,连续多年冻土区及大片多年冻土区植被生长季平均NDVI值呈显著上升趋势(p<0.05).对于不同植被类型而言,除森林植被NDVI呈显著上升趋势外(p<0.05),其它植被类型NDVI值无显著变化趋势.过去27年间,东北冻土区年均气温显著升高,年降水量显著下降,CO2浓度显著升高.研究区全区平均NDVI与年平均气温呈显著正相关(p<0.05),气温是影响东北冻土区生长季植被NDVI的主要气候因子.森林和沼泽湿地植被生长季平均NDVI与年平均气温呈显著正相关,与降水量呈显著负相关(p<0.05);5种植被类型中仅森林植被受CO2浓度影响显著.年平均气温对不同植被类型的影响由高到低的顺序为:森林>沼泽湿地>灌丛>农田>草地;降水的影响为:森林>沼泽湿地>草地>灌丛>农田;CO2浓度的影响为:森林>沼泽湿地>草地>农田>灌丛.
Based on GIMMS and MODIS remote sensing data from 1982 to 2008,we analyzed the spatial-temporal characteristics of vegetation Normal Difference Vegetation Index NDVI during the growing-season. We then explored the responses of NDVI to climate changes and the increased carbon dioxide concentration for different vegetation types in different frozen regions. The average growing-season NDVI value in different frozen regions is： continuous permafrost region mostly continuous permafrost region seasonal frozen earth region segregated permafrost region. For vegetation types, the average growing-season NDVI value is： forests shrubs marshes farmlands grasslands. The average annual growing-season NDVI value of forests is 0. 61,and that of grasslands is 0. 46. The past 27 years can be divided into three stages based on the annual variability of average growing-season NDVI： ①1982 ～ 1990,slight increase stage,②1990 ～ 2000,slow decrease stage,③2000 ～ 2008,obvious increase stage. The continuous and mostly continuous permafrost region experienced significantly increased vegetation NDVI from 1982 to 2008 （p〈0.05） . The NDVI values of forests had significant increasing trends,but other vegetation types showed no significant trends. In the past 27 years,the study area saw significantly increased air temperature,declined precipitation,and increased carbon dioxide concentration. The average growing-season NDVI for the whole study region was significantly positively correlated with annual average air temperature （p〈0.05） . It could be summarized that,in the frozen areas of Northeast China,the climatic factor controlling the growing season vegetation NDVI was temperature. Vegetation growing-season NDVI was effected by annual average temperature as follows： forests marshes scrubs farmlands grasslands; and by precipitation： forests marshes grasslands scrubs farmlands; by carbon dioxide concentration： forests marshes grasslands farmlands scrubs.
出处
《环境科学学报》
CAS
CSCD
北大核心
2010年第11期2332-2343,共12页
Acta Scientiae Circumstantiae
基金
中国科学院知识创新工程重要方向项目(NoKZCX2-YW-341)
国家自然科学基金项目(No40930527
40871187)
国家重点基础研究发展计划项目(No2009CB421103)~~
关键词
NDVI
气候变化
CO2浓度增加
东北冻土区
NDVI
climatic changes
increased carbon dioxide concentration
frozen areas of Northeast China
