未来气候变化对沙枣适宜分布区的影响预测

Predicting the influence of future climate change on the suitable distribution areas of Elaeagnus angustifolia

气候变化显著影响全球植物物种的地理分布,了解未来气候变化对我国造林树种适宜分布区的影响,及时采取应对措施,对提高造林的成效具有至关重要的作用.选取在荒漠化防治和退化土地修复中起重要作用的优良树种沙枣为研究对象,利用MaxEnt和GIS工具,基于182个来自标本馆、出版文献的记录和13个来自BIOCLIM、Holdridge生命地带、Kira指数的气候因子,预测其气候适宜区在未来气候情景下的变化.结果表明:未来(2070s) 4种气候情景对沙枣适宜区的影响存在差异,在低浓度温室气体排放情景(RCP 2.6)下适宜区面积将缩减,缩减的区域主要位于西北当前适宜分布区的边缘;而中等偏低浓度温室气体排放情景(RCP 4.5)、中等偏高浓度温室气体排放情景(RCP 6.0)和高浓度温室气体排放情景(RCP8.5)下,均有不同程度的扩张,扩张的区域主要位于西北暖温带干旱地区和东北部中温带半湿润地区;在RCP 8.5情景下,北部中温带干旱区和半干旱地区以及南方北亚热带湿润地区也有较明显的扩张.未来适宜区分布范围的地理质心将以6~19 km·(10 a)^(-1)的速度移动,海拔质心将以3~20 m·(10 a)^(-1)的速度向更低区域移动.沙枣稳定适宜区约占当前适宜区分布范围的83%~98%,当前的气候适宜区总体稳定.

Climate change significantly affects geographic distribution of plants worldwide. Understanding the influence of climate change on the suitable areas of afforestation tree species in China and taking timely countermeasures are crucial for improving the effectiveness of afforestation. Elaeagnus angustifolia is a good species for ecological restoration of degraded lands and control of desertification. Using MaxEnt and GIS,we predicted the changes of climatically suitable areas of this species under future climate scenarios,based on 182 records from herbaria and published literatures,and 13 climatic factors from BIOCLIM,Holdridge life zone and Kira index. The results showed that the four climate scenarios in 2070 s had different effects on the climatically suitable areas of this species. The suitable areas would shrink in the lowest greenhouse gas emission（ RCP 2.6）scenario. The shrinking areas were mainly located in the edge of the currently suitable areas in the northwest. The suitable areas would expand in the lower（ RCP 4.5）,the higher（ RCP 6.0） and the highest（ RCP 8.5） greenhouse gas emission scenarios. The expanding areas were mainly located in the northwestern arid regions of warm temperate zone,and northeastern sub-humid regions of middle temperate zone. There were obvious expansions in the northern arid and semi-arid regions of middle temperate zone,and southern humid regions of north-subtropical zone under RCP 8.5 scenario. The geographical centroids of future suitable ranges would move with a speed of 6-19 km·（ 10 a）^-1. The altitudinal centroids were predicted to move to lower regions with a speed of 3-20 m·（ 10 a）^-1. The stably suitable areas accounted for 83%-98% of the current distribution ranges of this species,which were generally stable under future climate change scenarios.