The Study On The Mechanism And Ecological Degradation Of Rock Desertification And Abandoned Mines

Rocky desertification is a process of exposed rock caused by man-made destruction,resulting in a decline in land productivity,reduced vegetation coverage,and severe soil erosion.Abandoned mines are areas where the original ecology was destroyed due to mining activities.It has environmental problems similar to rock desertification.This article discusses the manifestations and causes of the ecological degradation in the rock desertification area and abandoned mine areas,in terms of vegetation,climate,and soil.In addition,trees play an important role in the ecological restoration of rocky desertification,so this paper also conducts theoretical research on the physiological characteristics of trees in rocky desertification areas,and analyzes the performance and characteristics of tree degradation in rocky desertification areas through field sample surveys.The conclusions of this article are as follows:(1)The overall degradation model of rocky desertification is destruction of forest and grass→reclamation on steep slopes→soil erosion→exposed rock→rocky desert.(2)The vegetation in the abandoned mine area is directly destroyed,the manifestation of vegetation degradation in the abandoned mine area is similar to that of the severe rocky desertification area.(3)At the same time,the light intensity continues to increase with the increase of the rocky desertification level.The daily temperature in areas with varying degrees of rocky desertification is high at noon and low in the morning and evening.At the same time,the deeper the area of rocky desertification,the greater the average daily temperature and the temperature difference between day and night.The relative humidity of the atmosphere in the rocky desertification areas in different seasons and different degrees is high in the morning and evening,and low at noon.(4)In different areas of rocky desertification,there is no significant difference in soil pH;soil field water holding capacity,total soil porosity,capillary porosity,soil organic matter content,total soil nitrogen,alkaline nitrogen,total phosphorus,available phosphorus,total potassium and available potassium content decrease with the degree of rocky desertification;soil bulk density,compaction degree and temperature increase with the degree of rocky desertification.(5)The selection of tree species for vegetation restoration in rock desertification areas and abandoned mine areas should consider the tree’s needs for water,nutrients and climate,and its ability to resist heat and drought,according to the degree of rock desertification or the area where rock desertification is located.(6)According to the field research,the rocky desertification area of Shiqing Village,Nanping Town,Nanchuan District,Chongqing City is a moderate rocky desertification area.The geological and climatic conditions are conducive to the development of rocky desertification and there are local problems such as mining and reclamation to destroy the soil environment.Therefore,the specific performance and characteristics of tree degradation in the stone desertification area of Shiqing Village,Nanping Town,Nanchuan District,Chongqing are as follows:During the process of tree degradation,the tree tends to survive on stone table,stone-drain,and soil slopes which have thick soil layer,rich in deep fissures,fissure width greater than 5 cm;trees need to survive in areas where has rich plant community and the coverage of the community is at least 80%.The surviving trees generally have the characteristics of strong resistance to heat and drought,and strong vitality.Tree in the rocky desertification areas show degenerative characteristics of weak trunks and short stunts.Trees have little effect on the surrounding soil temperature and humidity,but in the process of rocky desertification,trees are more likely to live in where high soil humidity,high soil temperature and the temperature difference is small.In terms of the current situation of rock desertification in Shiqing Village,it is recommended to use the tree planting base technology of bare rock area to control the problem of rock desertification.