Spatial Distribution Of Vegetation And Its Influencing Factors In Lesser Xing'an Mountains

With the rapid population growth and rapid economic development,the environment in which human beings live has been severely damaged and triggered a series of environmental problems.Vegetation is a mirror of the environment,which has the functions of improving the environment,regulating the climate,intercepting precipitation,slowing runoff,combating desertification and soil and water conservation.Lesser Xing'an mountains is rich in vegetation.The study of vegetation and environmental factors in this area can provide a theoretical basis for the protection,management,restoration and reconstruction of vegetation in the region,and the development of rational resource utilization strategies.With the support of geospatial analysis and MaxEnt model,this paper uses the vegetation type data of Lesser Xing'an mountains and the data of 9 environmental factors in the area(altitude,slope,aspect,average annual precipitation and temperature,average precipitation and temperature in July).,the average annual minimum temperature,and soil type data)study the spatial distribution of vegetation and its impact factors in the region.The conclusions are as follows:1.Through the analysis of vegetation and environmental gradients,it is found that the average annual temperature is-0.5 ~ 0.2 °C,the average annual temperature in July is 19.4 ~ 20.3 °C,the average annual minimum temperature is-7 ~-6 °C,and the average annual precipitation is The amount is 550 ~ 600 mm,the average annual precipitation in July is 145 ~ 155 mm,and the altitude is 350 ~ 450 m,which is the most abundant environmental area of vegetation.The vegetation types in this area are mainly distributed in areas with slope less than 15 degrees;the concentrated soil types are dark brown soil;the distribution of vegetation in different slope directions is not significant.Find out the general distribution pattern of temperature from high to low for vegetation growth and the general distribution pattern of precipitation from high to low for vegetation growth.2.By constructing MaxEnt model of 14 main vegetation types,the model results show that the AUC value of Mongolian oak forest is less than 0.7,the prediction resultsare poor;the AUC values of Betula platyphylla forest,Ulmus pumila,Trollius chinensis and grassland meadow were less than 0.8 prediction results in general.the AUC value of poplar,linden,machinery forest,Korean pine,deciduous broad-leaved mixed forest,spring wheat,early maturing soybean,flax field and Xingan larch forest is less than 0.9and the prediction results are good.the AUC values of spruce forest,potato field,cabbage field,alpine meadow,Pinus sylvestris forest,fir forest,tiller grass,weed meadow were greater than 0.9,and the prediction result is very good.3.The average temperature in July is the dominant environmental factor for spring wheat,early-maturing soybean and flax field;the average annual minimum temperature is the dominant environmental factor of Larix gmelinii;the average precipitation in July is the dominant environmental factor of Elsholtzia thunbergii,grasses,weedy meadows and Pinus sylvestris var.mongolica forests.the dominant environmental factors of the remaining 10 plantations are average annual precipitation.4.The simulation results of the model are classified as follows: 0?P<0.1 is the unfit interval,0.1?P<0.3 is the low fitness interval,0.3?P<0.5 is the medium suiTab.interval,and 0.5?P?1 is the high fitness interval.And the distribution position of the high fitness interval and the area proportion of the medium and low fitness interval are described.