Spatial Heterogeneity Of Soil Properties In20Ha Dynamic Plot In Tiantong District,Zhejiang Province

The study of soil spatial heterogeneity is an effective way to explore the relationship of soil nutrients and environmental factors, the results can be used to get further understanding of soil formation process, structure and function, which had important theoretical significance and relationship with the plants and soil, such as vegetation regeneration the process of soil nutrients and moisture on root and plant.Partial pattern also has important reference value.In this study, spatial heterogeneity and distribution patterns of soil properties (pH, total carbon, total nitrogen and total phosphorus) were evaluated in a20ha of evergreen broad-leaved forest dynamic plot in Tiantong, Zhejiang province, by combing soil sampling and statistical methods. And influences of terrain factors (including elevation, convexity and slope) on soil properties were quantified based on RDA and partial regression analysis method. The main results of this study are as follows:(1) The soil properties exist spatial variation in Tiantong20ha evergreen broad-leaved forest dynamic monitoring plot, coefficients variation of pH, total carbon, total nitrogen and total phosphorus were5.18%,42.98%,36.55%and46.27%; spatial autocorrelation range of soil properties was81.6-54.5m. Soil pH, total carbon and total nitrogen showed scattered patchy spatial distribution, pattern of total soil phosphorus was banded structure. The structure of the study sample to the indicators of soil properties existed differences, total P self-correlation and spatial autocorrelation range was significantly greater than other soil properties index.(2) Sampling density affects the spatial variability of soil total carbon and have an impact on spatial prediction results:as the sampling density decreases, the total carbon had a weaker correlation, and the spatial autocorrelation process changed with the reduction of sampling density and larger changes. As the sampling density decreases, the spatial distribution of the whole carbon tend to homogenization; this homogenizing trend, resulting in a lower predictive value of accuracy, when the sampling density changed from85%to10%, the root mean square error (RMSE) raised2.442%.(3) Convexity, elevation and slope can be explained10.53%,7.47%and1.62% of the spatial variability of soil properties. Around all the terrain factors, the influence on the of soil pH and total phosphorus by convexity was greatest, their was a negative correlation, this factor alone can explain21.24%and14.62%of the variation of pH and total phosphorus space; altitude is the greatest impact to total soil carbon and nitrogen, both with a positive correlation, elevation alone explained10.54%and10.60%of the variation of total carbon and total nitrogen in space. Different terrain factors on indicators of soil properties spatial variability affect the extent there are differences, suggesting that the differences of the different terrain factors affect the mechanism, and topographic factors regulating the distribution of acidic rainfall in the region and impact of the local soil moisture content and temperature.