气候变化对梭梭植物适宜分布的影响

The impacts of climate change on the potential distribution of Haloxylon ammodendron

分析气候变化对植物分布的影响,对保护生物多样性有重要的现实意义。基于梭梭(Haloxylon ammodendron)的分布点数据和环境因子数据,利用最大熵(MAXENT)模型和GIS工具估计其在基准(1961—1990)及2050(2041—2060)和2070(2061—2080)时段基于RCPs气候情景下的潜在分布范围、空间格局及其变化。结果表明:(1)基准气候下,梭梭的分布主要集中在我国西北干旱区,尤其是新疆地区:古尔班通古特沙漠,塔里木盆地西端、北缘;内蒙古阿拉善左旗、东阿拉善;甘肃河西走廊;宁夏西部、北部;青海柴达木盆地东部和南部。在蒙古南戈壁省和东戈壁省有少量破碎化分布;(2)年平均降水量、最湿季平均气温、最干季降水量和降水季节性是限制梭梭分布的关键因子,累计贡献率达85.03%;(3)2050和2070时段,梭梭的适宜分布范围将显著增加,仅在塔里木盆地西端的分布将破碎、减少;分布范围及重心可能将向西北和东北方向迁移。

Understanding the impacts of climate change on the distribution of plant species is crucial for the conservation of biodiversity. On the basis of distribution data and environmental variables, we used a maximum entropy model （MAXENT） and GIS tools to estimate the potential distribution range, spatial pattern, and change of Haloxylon ammodendron under reference climate and in 2050 and 2070 （according to the RCP2.6 and RCP6.0 scenarios of IPCC）. We obtained the following results： （1） The potential distributions under the reference climate were mainly concentrated in the arid areas of northwest China, especially in Xinjiang： Gurbantunggut Desert, the northern margin and western tip of the Tarim Basin, Alax Left Banner and eastern Alax of Inner Mongolia; Hexi Corridor of Gansu Province; western and northern Ningxia; eastern and southern Qaidam Basin in Qinghai Province. Furthermore, small fragmented patches of suitable area were identified in mngovǐ and Dornogovǐ of Mongolia. （2） Annual precipitation, mean temperature of the wettest quarter, precipitation of the driest quarter and precipitation seasonality （coefficient of variation） mainly limited the distributions of H. ammodendron, and their total cumulative contribution rate was 85.03%. （3） In 2050 and 2070, the range suitable for H. ammodendron would increase significantly, whereas only a few distribution areas in the western tip of the Tarim Basin would fragment and decrease in size. The distribution range and gravity center would shift to northwest and northeast.