The Spatial Heterogeneity And Environmental Factor Analysis Of Soil Organic Matter In Patch Vegetation Area On Desert-oasis Ecotone

Arid areas in Northwest China due to different hydrological conditions,climate,vegetation and the impact of human activity,showed significant differences in soil organic matter content.Study on arid areas of spatial heterogeneity of soil organic matter and its influencing factors,to maintain the stability of OASIS ecology environment,further effective sustainable utilization of land resources in arid areas is of great significance.This study took the patch vegetation area on Desert-oasis Ecotone in the middle reaches of Hehe river as the study area,research analysis 0 ~ 120 cm soil depth soil organic matter of space different quality and discussion the environment effect factors(vegetation type,soil moisture,soil particles grain diameter,temperature,precipitation,and terrain,)on soil organic matter space distribution;At the same time,through using grey associated method inquiry all effect factors on soil organic matter space distribution of effect size.The main research results are:(1)On the vertical profiles of 0 ~ 120 cm soil depth,the soil organic matter in 0 ~ 20 cm soil layer was minimum and it was 1.888%;100 ~ 120 cm soil layer of soil organic matter content was maximum and it was 2.504%;0 ~ 120 cm soil layer soil organic matter content with increasing soil depth show increasing trend.(2)The coefficient of variation which soil organic matter contents in 0 ~ 120 cm soil layer is between 0.369 and 0.561 belongs to the medium variation.With the increase of soil depth,the variation coefficient of soil organic matter content showed a trend of decrease,and the soil organic matter contents variability in soil layer of 40 ~ 60 cm in depth was the most intense(3)The spatial variability model of soil organic matter contents in soil layer of 0~60cm in depth were pure gold model,and the layer of 60 ~ 120 cm in depth were index model and spherical models.(4)The percentage of surface soil organic matter content is random distribution of regionalized variables,the spatial autocorrelation does not exist,namely are remarkably influenced by external factors,including natural and artificial factors.Deep spatial heterogeneity of soil organic matter is mainly caused by structural factors(soil parent material,topography),research in deep space since the correlations of strong soil organic matter content,structural factors on the desert oasis vegetation transition zone plaques area played a dominant role in the spatial distribution of soil organic matter.(5)Vegetation,soil moisture,and soil particle size,rainfall,temperature,terrain and other factors will have an impact on the spatial distribution of soil organic matter.Different vegetation types can lead to differences between 0 ~ 120 cm soil layer soil organic matter content,under different vegetation types and the layers of soil organic matter content is higherthan that of bare soil organic matter content.0 ~ 120 cm soil on vertical distribution,the change trend of soil organic matter under different vegetation types,presents the first increase after the decrease trend.The increase of soil moisture content and clay content will cause the increase of the content of organic matter in soil both positively correlated with soil organic matter content;Precipitation and temperature on the influence of soil organic matter content,to some extent,soil organic matter content increased with the increase of precipitation increase,with the rising of temperature decrease;Terrain had effect on the spatial distribution of soil organic matter content,the effect is small relative to other factors.(6)With the gray relational coefficient compares the tightness of on the impact of various factors on soil organic matter.the surface soil layer of 0 ~ 40 cm,vegetation coverage the most dramatic effects on soil organic matter;the soil layer of 40 ~ 60 cm,soil moisture content has great influence on soil organic matter,the soil layer of 60 ~ 80 cm,vegetation coverage had the greatest influence on soil organic matter;the soil layer of 80 ~ 100 cm,the soil temperature had the greatest influence on soil organic matter;the soil layer of 100 ~ 120 cm,particle diameter d particle content of 0.075 mm or less impact on the soil organic matter is the largest.