摘要
气候变暖正在导致北半球多年冻土区的土地覆被类型和植被生物量发生快速变化,而不同冻土类型区和不同土地覆被类型区对气候变化的响应程度尚不清楚。基于Slope趋势分析和皮尔逊相关性分析,量化了2000~2021年北半球多年冻土区归一化植被指数(NDVI)的时空变化及其对气候变化的响应。结果表明:约21.43%的多年冻土区NDVI值表现出显著增长趋势,其中连续和不连续多年冻土区的NDVI值增长速率是零星多年冻土区的2~3倍。在月尺度上,约33.75%多年冻土区的NDVI值在6月呈显著增长趋势,其中连续多年冻土区和灌丛植被类型区的增长速率最快。气温、降水量和活动层厚度均呈显著上升趋势,积雪覆盖率呈下降趋势。气温升高对俄罗斯等低纬度冻土区的植被生长起到了促进作用;降水在蒙古高原等一些特定干旱区对植被生长具有促进作用,但在俄罗斯中部和加拿大南部存在不利影响;积雪对于俄罗斯南部等积雪覆盖较低地区的植被生长有促进作用,而对于北极等积雪覆盖较高的地区存在不利影响;活动层厚度的增加有助于俄罗斯北部等冻土区的植被加速生长。总之,北半球多年冻土区植被整体呈增长趋势,气温升高仍然是北半球多年冻土区植被生长的主控因素,但不同多年冻土类型区的NDVI值增长有着明显的月份差异,因此在以后植被模型的发展和改进时需要考虑月份的差异。
Climate warming is leading to rapid changes in land cover types and vegetation biomass in the permafrost regions of the Northern Hemisphere.However,to what extent of the vegetation growth responding to climate change in different permafrost regions and different land cover types regions is still unknown.The spatial-temporal change of normalized difference vegetation index(NDVI)and its response to climate variables from 2000 to 2021 were analyzed based on Slope trend analysis and Pearson correlation analysis.The results show that about 21.43%of the NDVI in the permafrost regions shows a significant increasing trend,in which the increasing rates of NDVI in the continuous and discontinuous permafrost regions are 2-3 times higher than that in the sporadic permafrost region.On the monthly scale,about 33.75%of the NDVI in the permafrost regions shows a significant increasing trend in June,with the fastest increasing rates in continuous permafrost regions and scrub vegetation type regions.Temperature,precipitation,and active layer thickness exhibit a significant increasing trend,while snow cover shows a decreasing trend.Warmer temperatures promote vegetation growth in low-latitude permafrost regions such as Russia.Precipitation promotes vegetation growth in some specific arid zones such as Mongolian Plateau,but has a negative effect in the central Russia and the southern Canada.Snowpack promotes vegetation growth in areas with low snow cover,such as the southern Russia,but has a negative effect in areas with high snow cover,such as the Arctic.In general,the vegetation within the permafrost region of the Northern Hemisphere is experiencing an overall growth trend,and that warmer temperatures are still the main controlling factor for vegetation growth in the permafrost region of the Northern Hemisphere.The increase in the active layer thickness contributes to the accelerated growth of vegetation in permafrost regions such as the northern Russia.In addition,the growth of NDVI in different permafrost types exhibits noticeable monthly variations,highlighting the need to consider these differences in future developments and improvements of vegetation models.
作者
李羽莹
刘桂民
吴晓东
王耀新
康国慧
赵俊
董云霞
王琳
LI Yu-ying;LIU Gui-min;WU Xiao-dong;WANG Yao-xin;KANG Guo-hui;ZHAO Jun;DONG Yun-xia;WANG Lin(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China;State Key Laboratory of Cryosphere Science,Northwest Institute of Eco-environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;Cryosphere Research Station on the Qinghai-Tibet Plateau,Northwest Institute of Eco-environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China)
出处
《地球科学与环境学报》
CAS
北大核心
2024年第3期321-333,共13页
Journal of Earth Sciences and Environment
基金
国家自然科学基金项目(41941015,32061143032)
中国科学院“西部之光”人才培养计划项目。
关键词
归一化植被指数
气温
降水
积雪
活动层厚度
时空变化
皮尔逊相关性分析
多年冻土区
NDVI
temperature
precipitation
snow cover
active layer thickness
spatial-temporal change
Pearson correlation analysis
permafrost region
