| China is one of the countries with the most serious problems of desertification in the world.Since the 1950 s,scholars in China have made many efforts to prevent and treat desertification,but the effect is "a total reversal and a partial lack of optimism." Therefore,this paper attempts to use the physico-chemical properties of soil as an indicator to assess the degree of desertification of different land-use types by constructing a desertification assessment model and provide a theoretical basis for desertification prevention and control work.The Horqin Sandy Land is located in the transitional zone between the Northeast Plain and the Inner Mongolian Plateau,the transitional zone of semi-humid and semi-arid climates,the transitional zone between forest steppe and arid steppe,and the agro-pastoral zone in northern China.The ecological environment is fragile.It is the most desertification in northern China at this stage.One of the serious areas.Although the desertification of the Horqin Sandy Land has reversed since 2000,the desertification status is still not optimistic.Therefore,the research on the desertification and ecological protection in the Horqin Sandy Land still have practical significance.The Naiman Banner Xinglongzhao Forest Farm is the construction area of ??the 009 project of “Three-north region afforestation,forestry research,planning and development”.Since its establishment in 1972,after more than40 years of hard work,the forest farm has been rich in land use types and its natural conditions have been improved.Improvement has become one of the successful examples of the rational use of land in China and the achievement of desertification control.Therefore,this paper uses the Xinglongzhao Forest Farm in Naiman Banner as the research area,and selects three types of land use types of cultivated land,forest land and grassland as research subjects,tries to use the soil physical and chemical properties as indicators,and evaluates the degree of desertification of different land use types by constructing a desertification assessment model.It provides theoretical support for the correct implementation of land use zoning in the area and smooth implementation of desertification prevention and control work.This article studies the following three aspects and draws the following conclusions.(1)Analysis of Soil Physical and Chemical Properties of Different Land Use Types in Xinglongzhao Forest FarmThrough analysis of variance,the characteristics of soil physicochemical properties in different land use types and different slope positions were explored,and on this basis,statistical analysis was made on the physical and chemical properties of different land use types.The results show:1 There are significant differences in soil mechanical composition between different types of land use and different slope positions.In the windward slope and the leeward slope,the forestland has the best effect of controlling desertification.On the top of the slope,the grassland has the best mechanical composition.Therefore,the grassland is the best choice for controlling the desertification on the top of the slope.The soil mechanical composition of the three types of land use and the different slope positions are the worst.This is because the arable land causes the surface to be exposed,and the loss of fine particulate matter in the soil under the action of wind erosion results in poor soil texture.Therefore,the study area is not suitable.reclamation.2 There are also significant differences in soil nutrient content between different land use types and different slope positions.In the windward slope and leeward slope,the control effect of desertification on the forest land was the best;on the top of the slope,the soil nutrient content in the woodland andgrassland was better.The soil nutrient content of the three types of land use,different slope positions,and cultivated land are the worst.This is because the arable land causes the surface to be bare,which results in the loss of fine particulate matter in the soil under the action of wind erosion,and reduces the ability to retain water and fertilizer in the soil.A large amount of loss,so the study area is not suitable for reclamation.(2)Evaluation of Desertification Degree of Different Land Use Types in Xinglongzhao Forest FarmBased on the above studies,this paper used the soil physical and chemical properties as indicators,and adopted a fuzzy comprehensive evaluation method and entropy weight method to establish a comprehensive assessment model of desertification degree,using desertified land and severely desertified land as background values ??for cultivated land,forest land,The degree of desertification of different land use types and different types of land use were evaluated.The results showed that the degree of desertification in the three types of land use and different types of land use in Xinglongzhao Forest Farm of Naiman Banner was the best,and the degree of desertification was the most serious.Therefore,it is necessary to strictly control the land reclamation and limit the grazing intensity of grassland in the study area.However,the forest land has a certain degree of desertification than undisturbed grassland.Therefore,maintaining the original grassland is the most efficient and most economical way to control desertification in the area.select.(3)Status of land desertification in Xinglongzhao Forest Farm of Naiman BannerOn the basis of the above research,through visual interpretation of TM image data at the end of July 2016,land use type maps of Xinglongzhao Forest Farm were obtained,and on this basis,land areas of different land use types were calculated.The total land area of cultivated land,forest land and grassland in the Xinglongzhao Forest Farm of Naiman Banner is 549.11km2,accounting for 76.19% of the total land area of the Xinglongzhao Forest Farm.Among the three types of land use,cultivated land accounted for the largest proportion,followed by grassland,and forest land occupied the least.It can be seen that the problem of land desertification in the Xinglongzhao Forest Farm in Naiman Banner still exists,and the desertification control work in this area still needs to continue efforts. |
