Research On Landscape Pattern Change And Ecosystem Function Value In Ganjiahu Wetland Edge

Xinjiang Ganjiahu wetland which located in Ganjiahu Haloxylon ammodendronForest National Nature Reserve is an important base, in which wetland and desertecosystem could be researched. It has very important strategic significance innorthern slope of Tianshan oasis ecological and economicse curity. Because of thelong time effect of human activities, such as overloading grazing, excessivecultivation and indiscriminate digging herbs, which made Ganjiahu wetland sufferingfrom severe degradation. This study selected wetland edge as the research area,which disturbance of human activities is more severe. This study used MSS data inMay,1972, ETM data in July,2000and IKNOS data in September,2008as remotesensing data sources. Using geographic information system, landscape ecologytheory, we research and discuss landscape dynamic degree, transfer matrix andlandscape pattern index in Ganjiahu Wetland edge about36years. Combined withprevious research results, we estimated ecosystem service value under the edge ofwetland landscape changes. The main results are as follows:(1) From1972to2008, the landscape dynamic degree and transfer matrix ofGanjiahu wetland edge showed the following characteristics: among landscapedynamic degree, the fastest growing in wetland or wetland edge were sandy, whichdynamic degree was1.62%,19.40%, respectively. It showed that sandy area ofwetland and wetland edge were increasing, but desertification phenomenon ofwetland edge was more serious than the wetland, duing to human activities influence.During the transformation of wetland landscape, grassland and swamp reduced inlarge scale, changed into sandy land. During the transformation of wetland edgelandscape, grassland, swamp and water which reduced in large scale, changed intoforest; sandy land increased in large scale, which came form forest.(2) From1972to2008, the changes of landscape pattern index of wetland edgeshowed that: The distribution of different types of landscape was tending to bedispersed and fragmentation.The fractal dimension of wetland landscape patchesincreased, and the self-similarity of landscape decreased, the diversity of wetlandlandscapes decreased.(3) The ecological function value of Ganjiahu wetland edge of the whole studyarea showed the following characteristics: Ecosystem service value of wetland were13.68×10~8yuan in1972and9.27×10~8yuan in2008, ecosystem service valuegenerally decreased4.41x10~8yuan in36years. Ecosystem service value of wetlandedge were3.24x10~8yuan in1972and2.31×10~8yuan in2008, ecosystem service value generally decreased0.93x10~8yuan in36years. The sum value of forest landand water account more than80%in the total value. Water conservation andutilization of waste were the main service function, both value account half in thetotal value.(4) This paper analyzed the driving force of the edge of the wetland withlandscape pattern change factors, from two aspects of natural and anthropogenicfactors, the studies shown that: natural factors was inherent reason in the degradationof wetlands, but human factors is a direct factor leading to the edge of the Ganjiahuwetland with landscape changes, such as cutting, herding and reclamation andexpanding to water resources.