Study On The Geographical Distribution Pattern Of Main Desert Plants In Temperate Zone In China

Under the background of global climate change,it is necessary to reasonably determine the potential suitable distribution range of climate change on temperate desert plants in China,the environment-driven mechanism,and the influence of future spatial pattern changes,so as to establish scientific and effective protection measures,which are important for the research and utilization of desert plants.The theoretical and practical significance.In this paper,the main vegetation types and dominant species of temperate desert in China recorded in "Chinese Vegetation" are based on 11 families,27 genera and 41 species.Five types of Prairie shrubs were selected,such as Helianthemum soongoricum,Potaninia mongolica,Caragana korshinskii,Ammopiptanthus Cheng,and Tetraena mongolica.Six kinds of desert shrubs,such as Nitraria roborowski,Gymnocarpos przewalskii,Ephedra przewalskii,Nitraria sphaerocarpa,Sarcozygium xanthoxylon and Calligonum roborowski respectively.Three kinds of Sandy shrubs,such as Calligonum leucocladum,Calligonum rubicundum and Calligonum mongolicum.Based on the geographic distribution point data and environmental data of 14 species of temperate desert plants,this paper uses Max Ent model and ArcGIS 10.2 tool to simulate its prediction in the reference climate(1970-2000)and future climate(2050 and 2070,RCP6.0 Scenarios of IPCC)for potential geographical distribution under the scenario,climatic factors for controlling the appropriate distribution range,spatial patterns under future climatic conditions and their changes.The main findings are as follows:(1)The AUC and Kappa values of the 14 desert plants predicted by the simulation in the reference climate,2050 periods and 2070 periods were greater than 0.95 and 0.85 respectively,indicating that the simulation results were reasonable and reliable;(2)Under the reference climate conditions,the potential geographical distribution of the 14 desert plants is basically consistent with the current known geographical distribution,which can better simulate the actual distribution.The key factors that limit the potential distribution of 14 desert plants are precipitation and temperature.Among them,the numerical range relationships of the most suitable potential distribution areas(potential occurrence rated ? 70%)and the first key factors of Prairie shrubs,Helianthemum soongoricum,Potaninia mongolica,Caragana korshinskii,Ammopiptanthus Cheng,and Tetraena mongolica,are as follows: Annual precipitation 80~350mm,Mean temperature of coldest quarter-40?~-75?,Mean temperature of coldest quarter-40?~-60?,Precipitation of warmest quarter 50~200mm and Mean temperature of coldest quarter-50 ? ~-75 ?,Desert shrubs Nitraria roborowski,Gymnocarpos przewalskii,Ephedra przewalskii,Nitraria sphaerocarpa,Sarcozygium xanthoxylon and Calligonum roborowski respectively: Mean temperature of coldest quarter-20?~-55?,Precipitation of wettest month 15 ~60mm,Precipitation of wettest month20 ~50mm,Precipitation of wettest month10~45mm,Precipitation of wettest month 20 ~80 and Precipitation of wettest month 0~20mm,Sandy shrubs Calligonum leucocladum,Calligonum rubicundum and Calligonum mongolicum respectively: Precipitation seasonality 0 ~ 45,Precipitation seasonality 0~50 and Precipitation of warmest quarter 50~150mm;(3)Compared with the reference climate in the 2050 and 2070 periods,The largest potential area for Prairie shrubs was the largest,followed by Desert shrubs and Sandy shrubs,which were 42.96%,24.19%,and 21.53%,respectively.The increase of 64.28% of the desert plants(Helianthemum soongoricum,Potaninia mongolica,Caragana korshinskii,Ammopiptanthus,Ephedra przewalskii,Nitraria sphaerocarpa,Calligonum roborowski,Calligonum rubicundum and Calligonum mongolicum)in the 2070 period was more significant than that in the 2050 period.Among them,the potential distribution areas of Potaninia mongolica,Ammopiptanthus and Calligonum rubicundum increased by 58.86%,56.51% and 41.86%,respectively,during the 2070 period,but the increase of Nitraria roborowskii was 63.01% at 2050;Potentially suitable areas for the distribution of 14 kinds of desert plants are mainly around the Gurbantunggut Desert and eastern regions in Xinjiang,Yili River Val ey and Turpan-Hami Basin along Turpan and Hami,Hexi Corridor north-west midwest region in Gansu,Northeastern,Northeast Badan Jaran Desert and northern Tengger Desert in Inner Mongolia;(4)Compared with the reference climate in the 2050 and 2070 periods,The potential distribution areas of Prairie shrubs and Desert shrubs are general y the same,with 6.8% and 6.3% respectively,and the minimum of Sandy shrubs is 4.98%.Among them,Calligonum rubicundum and Calligonum mongolicum had the smal est decrease(0.42%,0.04%),followed by Nitraria roborowskii and Ammopiptanthus(1.33%,0.38%),while the decrease in Calligonum roborowski and Calligonum leucocladum was the largest(30%,33%).The potential distribution areas of Potaninia mongolicad,Caragana korshinskii,Ephedra przewalskii and Tetraena mongolica decreased mainly in semi-circular distribution in Gulang,Baiyin,Lanzhou,Dingxi,Pingliang,Qingyang and Huachi in Gansu,Xiji,Haiyuan,Guyuan and other places in Ningxia and Dingbian,Jingbian,Yulin and Shenmu areas in Shaanxi.Caragana korshinskii,Nitraria sphaerocarpa and Calligonum roborowski showed a decreasing trend around the Gurbantunggut desert and eastern regions in Xinjiang,Ephedra przewalskii and Sarcozygium xanthoxylon are showing decreasing trends at the western and southwestern margins of the Tarim Basin;(5)From the reference climate,from 2050 to 2070,57.14% of 14 species of desert plants were planted(Helianthemum soongoricum,Potaninia mongolica,Caragana korshinskii,Tetraena mongolica,Nitraria roborowskii,Sarcozygium xanthoxylon,Calligonum leucocladum and Calligonum mongolicum)Appropriate distribution center of gravity to the high latitudes migrated more obviously,while 42.86% of the plants(Ammopiptanthus ? Gymnocarpos przewalskii,Ephedra przewalskii,Nitraria sphaerocarpa,Calligonum roborowski and Calligonum rubicundum)were suitable for the distribution of the center of gravity to low latitudes migrate.