Spatial Heterogeneity Of Shrub Vegetation And Soil Physical And Chemical Properties In The Upper Reaches Of Chongli Taizi City

In order to explore the relationship between biomass,diversity and soil physical and chemical properties of the shrubs in the upper reaches of the Taizicheng River,the typical plots were selected according to the altitude gradient for topographic survey,vegetation survey and soil survey,and the grassland vegetation and soil were analyzed by the least significant difference method.The spatial heterogeneity of physicochemical properties was finally analyzed by Pearson correlation analysis method.The correlation between the physical and chemical properties of different microtopography and the indicators of shrub communities and the biomass and species diversity of shrub communities were analyzed.The results show:(1)Spatial heterogeneity of shrub vegetationThe underground biomass is 1?27 times higher than the aboveground biomass,and the aboveground biomass increases slowly with the increase of altitude.The underground biomass remains basically unchanged with the elevation.The biomass under different slopes and slopes were significantly different.From the point of view of variability,the aboveground biomass with a coefficient of variation of 0.03 to 2.09 is higher than that of 0.05 to 1.04.Herbs are more abundant than shrubs and have better uniformity than shrubs.With the increase of altitude,the species richness,Simpson index,Shannon-Wiener index and Pielou evenness index all decreased.At 25°,the diversity of shrubs was the largest,and the downhill position was the best slope.(2)Spatial heterogeneity of soil physical and chemical propertiesThe physical properties of soil water content,bulk density,maximum water holding capacity,capillary water holding capacity,capillary porosity,total porosity and chemical pH value,organic matter,available potassium,available phosphorus,total nitrogen coefficient of variation are 0.001?0.31 1,0.019?0.072,0.026?0.385,0.017?0.315,0.009?0.224,0.002?0.250 and 0.001?0.060,0.013?0.252,0.018?0.168,0.019?0.167,0.025?0.290.The altitude is from 1500 to 2300m,the water content is almost unaffected,the bulk density is reduced by 41.42%,the maximum water holding capacity is increased by 61.45%,the capillary water holding capacity is increased by 40.81%,the porosity is basically unchanged,and the pH value is gradually reduced from 9.65.It is stable at around 7.5,the organic matter is increased by 17.24%,the available potassium is increased by 2.71 times,the available phosphorus is increased by 37.51%,and the total nitrogen remains basically unchanged.The slope increased from 200 to 40°,the water content decreased by 25.95%,the soil bulk density remained basically unchanged,the maximum water holding capacity and capillary water holding capacity increased by 9.33%and 14.09%,respectively,the porosity remained basically unchanged,and the organic matter decreased by 40%.The available potassium and available phosphorus increased by 51.1 1%and 84.01%,respectively,and the total nitrogen decreased by 70.83%.(3)Spatial heterogeneity of shrub vegetation and soil physical and chemical propertiesWater content,water holding capacity,bulk density and biomass showed a positive correlation,but porosity and biomass showed a negative correlation.The higher the altitude,the stronger the correlation between pH and biomass,and the positive correlation becomes a very significant negative correlation.Organic matter,available potassium,available phosphorus and total nitrogen were positively correlated with biomass.Soil bulk density and diversity showed a negative correlation,and water content,water holding capacity and porosity were positively correlated with diversity.In terms of correlation with diversity,total nitrogen>pH>quick potash>fast-acting phosphorus>organic matter.Combined with the topographical factors,it can be found that the elevation,slope and slope position of the most suitable irrigation grass in the upper reaches of the Taizicheng River are 1700?1950m,250 and downhill respectively.This paper can provide data support and scientific advice for the ecological reconstruction of the shrubs and grassland in the Chongli District by studying the spatial heterogeneity and relationship of the grasses and soils in the Taizicheng River.