Dynamic Evaluation On Ecosystem Service Values And The Driving Forces Of Karst Rocky Desertification Areas

Karst rocky desertification is the main eco-environmental problem which limits local ecological protection,economic construction and sustainable development of the mountain areas of Guizhou province,and even Southwest China.It would result exposure of base rock,loss of land productivity,and fragility of ecological environment.Dynamic evaluation and analysis of karst rocky desertification areas is the important precondition and basis of ecological property estimating,ecosystem restoring,and rocky desertification comprehensive control.Furthermore,it has the important theoretical value and practical meaning on ecosystem service evaluation of karst rocky desertification areas,and promoting harmonious development between human and nature.To solve the ecological problem on specific environmental conditions of karst rocky desertification areas,this study takes the Huajiang demonstration area in Guizhou Province as an example.Integrating remote sensing(RS)images,social investigation and field survey data,the ecosystems of the study area were classified by using technique of geographic information system(GIS),the Normal Different Vegetation Index(NDVI)and vegetation coverage were estimated,and then,the net primary production(NPP)was calculated based on carnegie-ames-stanford approach(CASA)model.Besides,using the ecosystem service value(ESV)evaluation model,the total ecosystem service values and each value of different ecosystem services of Huajing demonstration area in2000,2005,2010 and 2017 were assessed by market evaluation method,carbon tax law method,and shadow project method.The objectives of this study were to explore the spatial-temporal characteristics and variations of ESVs with different land surface features and to analysis the driving forces which resulting in the changing of ESVs in the study area.The major results were as follows:(1)The total ESVs of the study area were 3.025014×10~8 yuan in 2000,3.803461×10~8 yuan in 2005,4.578403×10~8 yuan in 2010 and 4.313343×10~8yuan in 2017,respectively.The supporting service values were the highest with2.34747×10~8 yuan in 2000,3.099037×10~8 yuan in 2005,3.778217×10~8 yuan in2010 and 3.434408×10~8 yuan in 2017,respectively;meanwhile,the cultural service values were the lowest,accounting for 1.80%of the total in 2000,1.44%in 2005,1.2%in 2010 and 1.38%in 2017;the order of ESVs of each type was supporting service values>providing service values>regulating service values>cultural service values.(2)The temporal variations of ESVs were:the total ESVs increased first and then decreased from 2000 to 2017,in which,the largest increase was7.78447×10~7 yuan,appearing from 2000 to 2005,and the decrease was 2.6506×10~7 yuan,appearing from 2010 to 2017.The spatial variations of ESVs were:the total ESVs were influenced by the ecosystem type and vegetation coverage.The areas with higher ESVs mainly distributed in Falang Formation,Bashan Village and Yintongwan Village,and the areas with lower ESVs mainly distributed in Tianba Formation,Dashiban Formation and Mugong Village.(3)From the perspective of different ecosystem types,the forest ESVs were the highest,accounting for 55.35%of the total ESVs in 2000,47.46%in 2005,41.49%in 2010 and 53.56%in 2017;bare land ESVs were the lowest,accounting for 1.21%of the total ESVs in 2000,1.94%in 2005,13.15%in 2010and 0.37%in 2017;the order of ESVs of individual ecosystem type was forest>farmland>grass land>city>water>bare land.Besides,the ESVs were correlated with levels of rocky desertification.In rocky desertification area,the ESVs decreased with the levels of rocky desertification up.(4)The ESVs changed from 2000 to 2017 in the study area,in which,the largest temporal variation happened from 2010 to 2017,fluctuating from-3.59×10~4 yuan/km~2 to 3.16×10~4 yuan/km~2;the larger spatial variation happened in Ganerpan Formation,Bashan Village and Yintongwan Village,the smaller ones happened in the western of Chaeryan Village and the western of Xiagu Village,and the smallest variation happened in Mugong Village.(5)The main driving force resulting in the changing of ESVs in the study area is the influence of human factors.Land use changing,eco-environmental quality,human disturbance intensity and engineering control of rocky desertification are by human activities change study area ecosystem types,eco-environmental condition,biological diversity and vegetation coverage and the influence of ESVs.