气候变化对东北主要地带性植被类型分布的影响

准确地划分地带性主要植被类型分布的适宜区域,可为区域植被恢复与重建、生物多样性保护等工作提供有益的理论参考。在检验1961—2013年东北地区气候变化突变点的基础上,基于东北地区主要植被类型热量指标,研究气候变化对该区域主要植被类型适宜分布区域的影响,并利用2000年和2013年土地类型覆盖数据(MCD12Q1),对推算的适宜分布区域进行验证,结果表明:大兴安岭气温突变点为1982年,其它地区为1988年,东北地区各生态地理区年降水量没有明显的突变点。气温突变点后适宜在东北地区生长的主要植被种类没有变化,但各植被类型的分布区域均有所改变,其中高山冻原、亚高山矮曲林、寒温带针叶林和温带针阔叶混交林适宜分布区域面积减小,暖温带落叶阔叶林和温带草原面积增大。气温突变点前后各植被类型适宜分布区的地理中心均发生了不同程度的移动,其中移动距离最大的是南部地区的亚高山矮曲林,向东北方向移动了135.44km。与主要植被类型实际分布相对比,证明气候变化对研究区植被类型分布可能已经产生了影响。

Effects of climate change on the distribution of main vegetation types in Northeast China

A suitable distribution of zonal vegetation types could provide a reference for the restoration and reconstruction of regional vegetation and protection of biodiversity. Between 1961 and 2013, we used mutation point detection and the thermal index to study the impacts of climate change on the distribution of the main vegetation types in Northeast China. The land cover data for 2000 and 2013 from NASA LPDAAC (The Land Processes Distributed Active Archive Center) EOS were used to verify the simulated distribution regions. The results showed that the temperature mutation point for Daxing''an Mountains was in 1982, and the mutation points for the other regions were in 1988. The annual precipitation at each eco-geographical region showed no obvious mutation. After 1982, the main vegetation types, which were suitable for growth,showed no obvious changes;however, their distribution regions had been changed. The areas of suitable distribution regions for alpine tundra, subalpine forest, cold-temperate coniferous forest, and temperate mixed forest decreased continuously;however, the areas for warm-temperate deciduous broad-leaved forest and temperate grassland increased. The geographic centers for the suitable distribution of each vegetation type had moved to different degrees before and after the temperature mutation points. Among them, the center of the subalpine forest had moved towards the northeast, and the distance was the longest (135.44km). On the basis of the comparative analysis,we concluded that climate change possibly had an impact on the distribution of vegetation types in Northeast China.