Landscape Pattern Change And Its Effects On Soil Organic Carbon Pool In Qinghai Lake Watershed

Landscape pattern change is bound to cause landscape cell changes in soil organic carbonpool (SOCP), in turn, the change of the SOCP, affect the evolution of the landscape pattern.This paper based on the3times TM image（1987,2000,2010）in Qinghai lake basin, afterpretreatment the original images, accordaning with the land use secondary classification, Qinghailake basin landscape is divided into16types through artificial interpretation. Further, according tothe landscape map which has been interpreted，through the calculation and analysis of landscapeindices were obtaining the transfer between different landscape, Finding transfer landscape rulesby analysis from years of1987to2010; Through literatures, soil census data and163laboratorytest soil profile data in2010, to determine the content of soil organic carbon density and itsdistribution law of9kinds landscape. After fitting the landscape change, Come to the conclusionof surface soil organic carbon stock changes and all library content of soil organic carbon inQinghai lake basin in2010. Discussing landscape pattern change and its effects of human andnatural factors on soil organic carbon pool change in Qinghai lake watershed. The results showthat:1. Landscape pattern from1987to2010was significantly volatility change in Qinghai lakewatershed, among them7class landscape area is increased, and9class landscape area is reduced.2. The index of landscape fragmentation mainly showed an increasing trend,enhancement oflandscape heterogeneity；As the change of environment and the implementation of protectionmeasures the index of landscape fragmentation mainly showed an decreasing trend. The shape oflandscape patches showed the tend to be more complicated from1987to2000, after year of2000the shape of landscape patches tend to be simple. Landscape diversity decreases first thanincreases, changes in volatility.3. Surface soil organic carbon density (0to30cm) significant changes have taken place from1987to2010in basin:4kinds of landscape types soil organic carbon contents had been decreased,on the other hand,5kinds of landscape types soil organic carbon contents had been increased. Thewhole of Qinghai lake basin soil organic carbon contents gradually present the trend of reducing.4.All landscape soil organic carbons released48.83×105t carbons from1987to2000.Affects by soil environmental change released45.00×105t carbons. Therefore，only consideringthe landscape changes of soil organic carbons released3.83×105t carbons, As the same，from2000to2010, all landscape soil organic carbons released53.80×105t carbons, effectd by soilenvironmental change released49.00×105t carbons, because of the landscape pattern changes,the soil organic carbons released4.80×105t carbon.5. The measured results in2010, showing that the amount of soil organic carbon stocks ofQinghai lake basin is about0.296PgC, Qinghai lake basin grassland covers an area about1.44%of the total Qinghai-Tibet plateau, then this area soil organic carbon contents accounted for3.38%,showing that Qinghai lake basin is one of the rich soil organic carbon content areas inQinghai-Tibet plateau.