未来气候变化对中国沙棘潜在地理分布的影响

Impact of climate change on the potential geographical distribution of Hippophae rhamnoides subsp.sinensis

中国沙棘作为重要的资源植物,具有较高的药用、经济和生态价值,也是森林和草原过渡带的重要指示物种。预测气候变化下中国沙棘的潜在地理分布,不仅能够揭示我国草原与森林植被带对全球气候变化的响应格局,也对中国沙棘资源保护和开发具有重要价值。本研究利用中国沙棘的分布数据,基于Biomod2组合模型,对未来气候变化下中国沙棘的适生区进行预测,并结合2020年中国土地利用类型遥感数据,分析适生区土地利用类型的变化趋势。结果表明:Biomod2组合模型相对于单一模型有效提高了中国沙棘适生区预测的精度和准确性。中国沙棘的分布区主要集中在辽宁到西藏的对角线两侧,处于森林和草原的过渡带。在SSP126情景下,未来中国沙棘的适生区呈先扩张后收缩的趋势;在SSP585情景下呈持续扩张趋势;在全球变暖的背景下,整体上中国沙棘未来的适生区呈扩张趋势。2050和2070年,中国沙棘适生区中草地的面积不断增加,而森林、耕地和建设用地的面积持续减少。在未来气候变化下,中国沙棘分布中心将向高海拔草原区域迁移。影响中国沙棘分布的环境因子以气候因子为主,其中,贡献率最高的是最暖季降雨量。

Hippophae rhamnoides subsp.sinensis is an important resource plant with considerable medicinal,economic,and ecological value,and an indicator species in the transition zones between forests and grasslands.Predicting the potential geographic distribution of H.rhamnoides subsp.sinensis under climate change can reveal the responses of China's grassland and forest to global climate change,which is of significance for the conservation and development of its resources.We utilized distribution data of H.rhamnoides subsp.sinensis to predict its suitable habitats under future climate change based on the Biomod2 ensemble model,and analyzed the trend of land use type change in these habitats in conjunction with remote sensing data of land use types in China in 2020.The results showed that the Biomod2 ensemble model significantly improved the accuracy and precision of predicting H.rhamnoides subsp.sinensis compared to single models.The distribution of H.rhamnoides subsp.sinensis was primarily concentrated on both sides of the diagonal from Liaoning to Tibet,situated in forest-grassland ecotone.Under the SSP126 scenario,the suitable habitats for H.rhamnoides subsp.sinensis would initially expand and then contract.Under the SSP585 scenario,they would show a continuous expansion trend.In the context of global warming,the suitable habitats for H.rhamnoides subsp.sinensis would expand.By 2050 and 2070,the area of suitable habitats for H.rhamnoides subsp.sinensis in grasslands would increase,while areas currently occupied by forests,croplands,and developed land would continue to decrease.Under future climate change,the distribution center of H.rhamnoides subsp.sinensis would migrate towards higher-altitude grassland areas.Among the environmental factors affecting the distribution of H.rhamnoides subsp.sinensis,climate variables were predominant,with the highest contribution of rainfall during the warmest season.