Study on the Spatial Variability of Soil Organic Matter in Napahai Degraded Wetland

This paper has mainly analyzed the spatial distribution of soil organic matter(SOM)under different human disturbances in Napahai wetland ecosystem, northwestern Yannan Plateau.Based on analyzing the statistical characteristics of SOM and soil degradation index(SDI), the following results were obtained:the horizontal variation of SOM content from four types of land utilization in Napahai wetland ecosystem is marsh >swamp meadow >reclaimed wetland >meadow, the coefficient of variation(C.V.)was 44.68%;and the vertical variation was obvious, i.e.the SOM contents of swamp meadow, meadow and reclaimed wetland in 0~20 cm layer was higher than those in 20~40 cm layer, the C.V.%was 63.32%, 54.95%and 49.93%, respectively.It was proved that SDI could be a quantitative index to show the degraded degree of wetland SOM under different human disturbances.It was showed that Napahai wetland had been deteriorating by human beings, the more intensive disturbance, the more serious degradation.