榆属植物是我国重要的植物资源,评价榆属植物生境适应性对于其保护具有重要意义。采用R语言Kuenm包优化最大熵(MaxEnt)模型,分析影响内蒙古榆属植物分布的主要环境因子,预测在2种气候情景(SSP126、SSP585)下,3个未来时期(2041—2060年、2061—2080年、2081—2100年)内蒙古榆属植物的潜在分布范围。结果表明:1)影响内蒙古榆属植物分布的主要环境因子为年平均气温和海拔,二者的贡献率分别为36.1%和23.9%;其次是最潮湿月降水量和气温季节性变化标准差,贡献率分别为15.2%和11.5%。2)1970—2000年内蒙古榆属植物潜在适生区面积为5.12×10⁵km²,呼和浩特、乌兰察布和锡林郭勒是主要分布区。3)在未来气候情景下,内蒙古榆属植物适生区发生不同程度的迁移和退化。特别是在SSP585情景下,适生区破碎化严重,高适生区几乎完全退化。到21世纪末,内蒙古榆属植物的适生区面积分别退化至3.54×10⁵km²(SSP126)、1.75×10⁵km²(SSP585),退化程度分别为30.8%、65.8%。在未来时期,潜在适生区中心质点向高原气候区及高纬度地区迁移。气候变化对榆属植物的影响较为显著,适生区面积减少,适生区等级逐渐降低,应加大对内蒙古地区榆属植物的保护力度。基于适地适树原则,建议在包头、呼和浩特和锡林郭勒等地区增加榆属植物的种植。

The genus Ulmus is an important plant resource in China,and assessing its habitat adaptability is crucial for its conservation.Utilizing the MaxEnt model optimized through the Kuenm package in R language.It investigated the key environmental factors influencing the distribution of Ulmus species in Inner Mongolia and predicted their potential distribution under two climate scenarios(SSP126 and SSP585)across three future periods(2041—2060,2061—2080,and 2081—2100).1)The primary environmental determinants of Ulmus distribution in Inner Mongolia are mean annual temperature and elevation,contributing 36.1% and 23.9%,respectively.Precipitation in the wettest month and the standard deviation of temperature seasonality are also significant factors,with contribution rates of 15.2% and 11.5%,respectively.2)The current potential suitable habitat area for Ulmus species in Inner Mongolia is 5.12×10⁵ km²,with Hohhot,Ulanqab,and Xilin Gol being the primary distribution areas.3)Under future climate scenarios,Ulmus habitats in Inner Mongolia will experience varying degrees of migration and degradation.Notably,under SSP585,habitat fragmentation will be severe,with high-suitability areas nearly disappearing.By the late 21st century,the suitable habitat area for Ulmus will decline to 3.54×10⁵ km² under SSP126 and 1.75×10⁵ km² under SSP585,corresponding to degradation rates of 30.8% and 65.8%,respectively.Future projections indicate a shift in the centroid of suitable habitats towards plateau climates and higher latitudes.Climate change poses a significant threat to Ulmus species,leading to a reduction in suitable habitat areas and a decline in suitability grades.Consequently,conservation efforts for Ulmus in Inner Mongolia should be intensified.Based on the principle of matching tree species to site conditions,it is recommended to prioritize Ulmus planting in regions such as Baotou,Hohhot,and Xilin Gol.