Study On The Precise Spatial Distribution Of Plant Growth Suitability In Hunshandak Sandy Land

Hunshandak sandy land is one of the main animal husbandry bases in Inner Mongolia,and it is also an important ecological barrier for Beijing and Tianjin.However,due to its fragile ecology and degraded vegetation,the government tried to quickly restore vegetation.In the face of this demand,it is of great significance for the restoration of artificial vegetation in this region to accurately select suitable plants for different habitats and community succession stages in different locations.Based on the principle of spatial information science and geostatistics,this study combines the sample survey data with the spatial distribution data of 30 m ecological environment factors,uses TWINSPAN model to divide the plant community types in this area,and uses Spearman correlation analysis to screen the ecological environment factors related to the suitability of plants in sandy land.The maximum entropy model was used to simulate the growth suitability distribution of various shrub and grass communities.Using the weighted evaluation model of AHP and entropy weight method to get the growth suitability distribution of each tree.Through GIS spatial analysis,the spatial distribution pattern of plant species and ultimate successional plant communities suitable for restoration in each plot was depicted.The specific conclusions are as follows:(1)The plants in Hunshandak sandy land are divided into 8 communities,among which the natural communities are: the pioneer communities of Agriophyllum squarrosum and Salsola collina distributed in the shifting sandy land;the perennial herbaceous communities of Elymus dahuricus and Salsola ruthenica in the semi-shifting sandy land;the plant communities with Carex and Artemisia halodendron as the construction species in the semi-fixed sandy land;the typical grassland communities with dominant species of Cleistogenes squarrosa,Leymus chinensis and Artemisia desertorum in fixed sandy land;and the communities of Achnatherum splendens and Sanguisorba officinalis distributed inthe flood land.Communities of Hedysarum mongolicum,Salix gordejevii,etc.in semi-fixed sandy land restored artificially;aerial seeding communities of Salix cheilophila and Caragana korshinskii in fixed sandy land and Pinus sylvestris and Populus plantations mainly distributed in the eastern mountains of sandy land.According to the community division,suitable plants can be provided for different stages of vegetation restoration.(2)Based on the principle of maximizing data information and minimizing redundancy,15eco-environmental factors affecting the suitability of plant growth in the region are selected,including soil p H(KCl),soil clay content,soil cation exchange capacity,annual precipitation,accumulated temperature,frost free period,atmospheric dryness,daily sunshine hours,annual evaporation,wind speed,atmospheric pressure,relative humidity,slope,aspect and elevation Factor.Through the selection,the ecological environment factors were provided for the simulation of plant growth suitability distribution.(3)According to the current spatial distribution of ecological environment conditions,in Sunit Right Banner and the northern of Sunit Left Banner,it is suitable for cutting Salsola collina in the shifting sandy land with an altitude of 890-1305 m and a gradient of less than 15 °,for setting up Agriophyllum squarrosum barriers in the shifting sandy land with an altitude of 978-1305 m and a gradient of less than 15°,for planting Bassia dasyphylla and Artemisia scoparia in semi-shifting sandy land with an altitude of 890-1580 m and a gradient of less than 15 °.In Zhengxiangbai Banner,Zhenglan Banner and the northern of Xilinhot,it is suitable to plant Caragana korshinskii,Artemisia frigida and Salix cheilophila on the windward slope of the semi-fixed sandy land;and it is suitable to plant Caragana korshinskii,Hedysarum mongolicum and Astragalus adsurgens on the semi-fixed sandy land leeward slope with an altitude of 1060-1485 m and a gradient of less than 18°.It is suitable to plant Trollius chinensis and Sanguisorba officinalis on the catchment area of the valley and depression between hills.In the mountainous of the southeast of Zhenglan Banner,Keshketeng Banner and Duolun County,it is suitable to plant Populus alba var.pyramidalis and Populus hopeiensis on the shady slope and semi shady slope of the mountains with an altitude of 1196-1818 m and a gradient of less than25°;it is suitable to plant Pinus sylvestris in the area with the elevation of 1196-1760 m and a gradient of less than 25°.(4)Following the succession law of sandy land community and combining with the constructionof sandy land industry,the suitable plant species for vegetation restoration in different stages of succession can be selected.Salsola collina and Agriophyllum squarrosum can be planted in the shifting sandy land.After 2 years of succession,the first and second-year herbaceous community stage came into being.In the semi-shifting sandy land of the western desert steppe,Bassia dasyphylla and Artemisia scoparia can be planted in the area with an altitude of 890-1580 m and a slope of 15 °below.The semi-shifting sandy land in the middle typical grassland and the eastern meadow steppe can be planted with native herbages such as Agropyron cristatum,Elymus dahuricus.After 4 years of succession,it reached the stage of multi-year rooting grass community.The semi-fixed sandy land is suitable for the shrub fixed sandy land such as Caragana korshinskii,Caragana microphylla,Salix cheilophila.After 10 years of succession,the perennial tufted grass community dominated by Stipa is the ultimate succession community in the desert steppe.The fixed sandy land of the typical steppe and meadow steppe can be planted with Caragana microphylla and Artemisia desertorum on the sunny slope and semi sunny slope of with the altitude of 1100-1980 m and the slope below 40°,Caragana korshinskii and Hedysarum mongolicum on the shady slope and semi shady slope,and Populus alba var.pyramidalis and Populus hopeiensis can be planted on the shady slope and semi shady slope of the northeast and southeast mountains,Pinus sylvestris can be planted on sunny slope and semi sunny slope.After 15 years of succession,elm sparse forest mixed with trees,shrubs and grasses will be the ultimate community.