Study On Response Mechanism And Tolerance Capacity Of Land Ecological Environment To Human Activities In Karst Mountainous Areas

The ecological environment security of land is the basis of regional ecological security.The karst mountainous regions of Guizhou Province belong to typical fragile ecological areas.A series of land ecological environment problems have become the bottleneck of restricting the development of the province.This article selects Qinglong County,Guizhou Province,which can represent the characteristics of karst mountains,as a research area.Based on the PSR-TOPSIS method,the health status of land ecological environment in Qinglong county was evaluated.On the basis of analyzed the impact of human activities on the ecological environment of the land,used the coordination degree,coupling degree,and responsivity models of the relationship between human activities and land ecological environment,Explored the response mechanism of unearthed ecological environment to human activities.The marginal land ecological environment influence model and the marginal land ecological environment change rate model were introduced to calculate the tolerance range of land ecological environment to human activities.This paper attempted to quantify the tolerance of land ecological environment to human activities and generated a response mechanism.Providing new ideas and references for such research.It is of great significance for the restoration of land ecological environment in Guizhou province and even in the karst region of China.The results showed as follow.(1)The land ecological environmental health and healthier areas were mainly distributed in the southern parts of Qinglong County in 2015.The morbid areas,unhealthy areas,and sub-health areas are located in the north.As for Qinglong County itself,it was in a relatively healthy state,but in the 14 villages and towns,7 villages and towns were in the morbid,unhealthy and sub health,the level of the land ecological environment in the county still needs to be improved.(2)The human activity intensity index continued to increase from 1988 to 2016.The disturbance of human activities has led to drastic changes in the type of land use in Qinglong County.The arableland,unused land,waters in Qinglong County were converted into grassland,industrial and mining land in urban and rural areas,and residential land.The area of forest land increased first and then decreased.The vegetation coverage index and landscape diversity index of Qinglong County gradually increased,and the landscape dominance index,landscape fragmentation index,net primary productivity,ecological service value,and land ecological risk index increased first and then decreased.(3)From 1988 to 2016,the relationship between human activities and land ecological environment in Qinglong County experienced a well-coordinated and running-in state,coordination of general and antagonistic status,highly coordinated and running-in state.There was a negative response between human activities and the land ecological environment.The response mechanism showed that the response had not been triggered since 1988,and it was initiated in 2000.The land ecological environment gradually began to resist human activities from self-repair.By 2016,human activities will promote the improvement of the level of land ecological environment.(4)In the period of 2000 to 2015 years,the tolerance range of land ecological environment to human activities was large in 2000 and 2001.The range of tolerance dropped significantly from 2001 to 2002.From 2009 to 2011,it was the inverted V shape trend that rose first and then declined.The tolerance range has shown fluctuations during the 2002 to 2009 and the 2011 to 2015.When the range of tolerance is small,on the basis of controlling human activities,corresponding measures should be taken to improve the level of land ecological environment in order to form a harmonious symbiotic situation between human and land ecology.