气候变化下中国潜在植被演替及其敏感性

The succession of potential vegetation in China and its sensitivity under climate change

潜在植被的研究能够真实反映气候条件对植被形态变化的影响,是植被-环境分类与关系研究的起点,也是全球变化与陆地生态系统研究的关键,对区域植被生态的恢复和重建具有重要的指导意义。本研究基于综合顺序分类系统,对过去30年(1986—2015年)和IPCC5发布的RCP4.5情景下未来3个时期(2030s、2050s和2080s)潜在植被的空间分布进行了GIS模拟,并分析了潜在植被对气候变化响应的敏感性。结果表明:(1)中国分布的潜在植被类型数量及各类在不同时期所占比例均存在差异,同时炎热极干热带荒漠类(VIIA)为各个时期共同缺失的潜在植被类型。(2)潜在植被的分布面积整体上呈现出冷干型潜在植被类型面积逐渐减少、暖湿型潜在植被类型面积逐渐增加的趋势,具体表现为扩展型、缩减型和波动型3类;潜在植被类组的重心发生了不同方向、不同距离的移动变化。(3)中国潜在植被对气候变化的响应存在敏感性差异,其空间分布形态总体呈现出不同敏感性程度的区域相间分布的特点。敏感性高的区域、敏感性较高的区域和敏感性较低的区域分别占国土总面积的2.28%、14.39%和43.82%。

The study of potential vegetation can reveal the impacts of climate on vegetation. It is the starting point for studying vegetation-environmental classification and relationships,and the key point for studying global change and terrestrial ecosystems. It has guiding significance for the restoration and reconstruction of regional vegetation. Using the comprehensive sequential classification system（ CSCS）,we carried out a GIS simulation study on the spatial distribution of potential vegetation in China in the past 30 years（ 1986-2015） and the future three periods（ 2030 s,2050 s and 2080 s） under the RCP4.5 scenarios issued by IPCC5,and analyzed its sensibility to climate change. The results showed that：（ 1） Differences existed in the number of potential vegetation classes and the proportion of each class in different periods. The tropical-extrarid tropical desert（ VIIA） was commonly absent in all periods.（ 2） With respect to the distribution area of potential vegetation,the area of cold-dry potential vegetation decreased whereas that of warmhumid potential vegetation increased,with extension,reduction and fluctuation being the three typical variation patterns. Moreover,the gravity centers of potential vegetation categories moved in different directions and at different distance.（ 3） The sensitivity of potential vegetation to climate change differed,with different sensitivity regions showing an interphase distribution. The distribution areas of regions with the highest,higher,and lower sensitivity accounted for 2.28%,14.39% and 43.82% of the total national area,respectively.