Abstract:Picea meyeri was listed as Ⅱ protected rare and endangered species in Inner Mongolia in 1989. Based on the records of 50 effective distribution points and 12 environmental factor variables of P. meyeri in China, this study used MaxEnt model and ArcGIS software to analyze the potential geographical distribution of P. meyeri in China in four periods of midHolocene, modern, 2050 and 2070. The contribution rate of environmental factors and the knifecut test were used to determine the dominant factors limiting the modern potential geographical distribution, and the response curve was used to determine the appropriate range of environmental factor variables, so as to clarify the potential geographical distribution area and area of P. meyeri in different periods, and provide the basis for the introduction and protection management of P. meyeri. The results showed that: (1) the area of receiver operating curve (AUC) predicted by MaxEnt model was 0.979, indicating that the prediction accuracy of the model was accurate and the reliability of the prediction results was high. (2) The main climatic factors affecting the potential distribution of P. meyeri and their suitable growth ranges are: altitude (1 200-2 300 m), the ratio of diurnal temperature difference to annual temperature difference (25%-28%), the wettest monthly rainfall (90-145 mm) and the annual average temperature (0-5 ℃). (3) The potential geographical distribution of P. meyeri which is mainly located in the middle and western part of Inner Mongolia (Jiufeng Mountain, Zhenglan Banner, Duolun County), most of Shanxi Province (Dashidong, Wutai Mountain) and part of Hebei Province (Wuling Mountain, Saihanba) in China has total area of 1.0356×106 km2. (4) From the middle Holocene to modern climate conditions, the potential distribution area of P. meyeri in the northern high latitudes of Inner Mongolia decreased, the survival suitability decreased, and most of the most suitable areas in central Inner Mongolia lost; under the RCP2.6 emission scenario in 2070, the suitable areas of P. meyeri in low latitude areas such as Shanxi Province and Hebei Province were also basically lost. Compared with the modern distribution area, the suitable areas of P. meyeri under future climatic conditions were reduced and migrated to the northeast of Inner Mongolia. Studies have shown that from the middle Holocene to 2070, the potential distribution area of P. meyeri gradually narrowed, and there was a trend of migration to high latitude and high altitude areas, and its most suitable area also moved to northeast Inner Mongolia.
