Abstract:

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.

Key words: Ulmus, Inner Mongolia Autonomous Region, MaxEnt model, distribution of suitable habitats