Comprehensive Evaluation Of Alpine Grassland Degradation In Qinghai Province

The alpine grassland is extremely fragile and it is very difficult to recover once it is destroyed.It is extremely prone to degradation.Degradation of alpine grassland will directly threaten the regional ecological security and economic development.Comprehensive evaluation on the degradation of alpine grassland can help to understand the characteristics of degraded alpine grassland and the temporal and spatial changes,which is of great significance for the prevention of alpine grassland degradation and ecological protection.Qinghai Province has a unique and typical alpine grassland ecosystem.It is a typical representative of the alpine environment of the Central Asian Plateau and the world’s alpine grassland.This study used Qinghai Province as a research area and collected data on basic geography,socio-economic and scientific surveys in Qinghai Province from 2005 to 2014.Based on the basic characteristics of alpine grassland degradation,this paper evaluated the degradation of alpine grassland in Qinghai Province by comprehensively evaluating the degradation of vegetation and soil in alpine grassland.Among them,the assessment of vegetation degradation in alpine grassland included changes in the vegetation status and the productivity of the alpine grassland.The assessment of the soil degradation of the alpine grassland mainly included the assessment of soil erosion trends in the alpine grassland.The trend assessment of vegetation growth in the alpine grassland was conducted by constructing an evaluation model of vegetation growth status of alpine grassland,and making regression analysis on the evaluation results during 2005-2014.When constructed the evaluation model for the vegetation growth status of alpine grassland,the effects of natural factors and human factors were comprehensively considered.Natural factors mainly considered the impact of climate factors and rodent damage;climate factors mainly included precipitation,temperature,solar radiation,and wind speed.Considering that different types of grassland have different sensitivities to climatic factors,the climatic factors assessment method was innovatively proposed,which is applicable to evaluate the regional changes in vegetation growth condition of alpine grassland.The change trend evaluation of vegetation productivity in the alpine grassland was conducted by constructing an evaluation model of the productivity of alpine grassland vegetation,and making regression analysis on the evaluation results during 2005-2014.When constructed an evaluation model of the productivity of alpine grassland vegetation,the effects of weeds were mainly considered.The assessment of soil erosion trend in the alpine grassland was conducted by constructing an evaluation model of soil erosion in alpine grassland,and making regression analysis on the evaluation results from 2005 to 2014.Based on the revised model for general soil erosion,when constructed an evaluation model for soil erosion in alpine grasslands,the effects of rainfall erosivity factor,soil erodibility factor,slope gradient factor,vegetation cover factor,and human activity interference factor were mainly considered.Based on the results of the comprehensive evaluation on the degradation of alpine grassland in Qinghai Province,it can be seen that most regions of the alpine grasslands in Qinghai Province showed a good recovery trend from 2005 to 2014.This reflects the effects of the grassland protection in Qinghai Province in recent years.However,it is obvious that the situation of the degraded alpine grassland in the central and eastern regions of Qinghai Province remains severe.Through the evaluation of vegetation degradation and soil degradation in alpine grassland,the main forms of grassland degradation can be further understood.The degraded alpine grasslands in the northern and eastern parts of the Yushu Tibetan Autonomous Prefecture and the southern part of the Guoluo Tibetan Autonomous Prefecture were mainly caused by the vegetation degradation,while the eastern part of the Haixi Zhou,the southwest of the Huangnan Tibetan Autonomous Prefecture and the northeast part of the Guoluo Tibetan Autonomous Prefecture were mainly due to the soil degradation.In addition,according to the results of climatic factors assessment in the vegetation growth condition of alpine grassland,it can be seen that the effects of different climatic conditions on the vegetation growth status of different alpine grassland types varied.The effects of temperature on the vegetation growth status of different alpine grassland types had a little difference,but precipitation,solar radiation,and wind speed were not the same.And,there were obvious differences in climate factors assessment models between alpine desert grassland and the others alpine grassland types.The verification of the evaluation results was based on the 43 monitoring sample provided by the Qinghai Province Grassland Station,on which contained the vegetation coverage,the ratio of edible herbage,and the soil organic matter content.These 43 monitoring sample were used to compute the trend indices from 2005 to 2014 to make the correlation analysis with the comprehensive evaluation result of alpine grassland degradation in Qinghai Province,which verified the accuracy of the comprehensive evaluation results.The analysis results showed that the P-values of these two indices are less than 0.01 and passed the significance test.The R-value is 0.504,indicating that the correlation between these two indexes is correlative.In summary,the paper proposed an effective comprehensive evaluation method for alpine grassland degradation,and comprehensively evaluated the specific conditions of alpine grassland degradation in Qinghai Province from 2004 to 2015,which can provide theoretical guidance and technical support for ecological protection and rational development of alpine grassland in Qinghai Province.It had certain innovation and practical significance.