Studies On Changes Of Landscape Pattern And Soil Organic Carbon Storage In Rorergai Wetland

In this paper,the indexeses of 1977,1994 and 2006,three remote sensing data of Landsat satellite images,in the ArcGIS 9.0 platform,select the number of landscape patches,size,shape index, density,fractal dimension,diversity index and a variety of landscape pattern index Ruoergai analysis of the National Nature Reserve and its surrounding areas,the evolution of the landscape pattern characteristics;At the same time,according to landscape classification system to study the meadow soil, aeolian sandy soil,black carpet soil,peat and swamp soil surface 20cm and 1m deep soil organic carbon density and changes in reserves,the results are as follows:According to the characteristics of the study area and the Guardian piece on the visual interpretation of the ability to carry out the three-tier division,which includes a landscape 2 landscape elements,including two landscape 6 landscape elements,including 10 categories of the three landscape elements of the landscape.With climate change and man-made interventions to strengthen,29a landscape between the entire study area constitutes the type of change,but change the landscape area of a larger area of wetland landscape dramatically reduced,rather than the wetland area is increased dramatically;plan the total number of plaques After a first increase in the trend of decreasing;matrix of marsh landscape from the past and into the grass lawn,grass on the landscape continuously strengthen the control;wetlands dry landscape constantly shrinking lakes,the most serious degradation.Elements of the landscape characteristics of plaque showed that,with the exception of lakes, seasonal water swamps,sub-alpine meadows and patches of land for construction purposes decreased density,the other landscape patch density increased in varying degrees;the corresponding river,water swamps,sub-alpine grasslands,sub-alpine scrub and grassland landscape boundary does not use an increase in density,and the rest showed a decrease trend;water marshes mean patch shape index value changes in the largest lakes,sub-alpine grassland,sub-alpine shrub grassland,construction land and unused land continued to decrease,while the rest of the landscape types of growing;sub-alpine grassland landscape similarity index(LS) the biggest change.Different times of the landscape diversity index analysis showed that the study area throughout the Shannon diversity index and evenness index showed a downward trend,and landscape dominance index showed a larger increase.Fractal dimension (F) analysis showed that the majority of the study area is similar to the shape of the landscape,the changes in a relatively stable state,and the complexity of the shape of the river is still larger,lakes and construction sites of the largest F value changes.Study area maps of different periods show that the soil,black soil area felt the largest increase,soil and peat swamp area of a significant decrease in the area of sand before the wind to reduce the increase. The study area of 58 samples of 163 soil samples from the soil surface and 1m deep 20cm of soil organic carbon content,density and organic carbon analysis showed that,with the exception of the wind is slightly lower organic carbon content of sand,the meadow soil,black carpet soil,swamp peat and soil organic carbon content in surface soil are higher than the national average soil content of topsoil.20cm and 1m deep surface soil organic carbon density,organic carbon in peat deposits were found in compliance with＞swamp soil＞meadow soil＞black carpet soil＞sand the law of the wind,the surface soil organic carbon density in the range of 0.21～32.86kg m^-2,the average swamp land values were 25.70 kg m^-2＞swamp soil 16.79 kg m^-2＞meadow soil 12.91 kg m^-2＞carpet soil and 9.43 kg m^-2＞Sand 2.80 kg m^-2;1m deep soil organic carbon density ranged from 1.04～154.87 kg m^-2,average soil, followed by swamp 125.93 kg m^-2＞swamp land 92.01 kg m^-2＞meadow soil 35.62 kg m^-2＞carpet soil and 25.50 kg m^-2＞Sand 11.58 kg m^-2.1m deep soil organic carbon stock changes showed that the peat soil,meadow soil and marsh soil organic carbon storage in a significant reduction,while the black carpet soil organic carbon reserves are increasing,the wind sand organic carbon there was a slight increase in reserves,but much to increase the number of as to reduce the number.29a between the entire study area,1m deep reserves of soil organic carbon in a decrease of 66.418 billion kg.This shows that the wetland is a great source is a carbon sink.