Soil Fertility Characteristics And Influencing Factors Of Chinese Fir Plantation And Moso Bamboo Forests In Dagang Mountain

In order to understand the soil fertility characteristics and influencing factors of Chinese fir(Curninghamia lanceolata)plantation and bamboo(Phyllostachys pubescens)forests in Dagang Mountain,the methods of literature retrieval and indoor supplementary experiments were used to describe the changing characteristics of soil properties of different forest types.Principal component analysis(PCA)was used to screen the main fertility indexes of two forest types of soil.Correlation analysis and path analysis were used to explore the effects of other soil properties on the main fertility indexes of soil.The fertility status of Chinese fir and bamboo forests was also comprehensively evaluated.The main results are as follows:(1)the two forest soils belong to loam soil,which are slightly acidic or neutral.Different properties showed different variation characteristics,most of them belonged to medium intensity variation,while soil bulk density,total porosity,capillary porosity,pH,available potassium content and other indicators belonged to weak variation intensity.The number of fungi and the activity of polyphenol oxidase varied relatively strongly,reaching a strong degree of variation.(2)the soil properties of the same layer of the two forest types showed different changes,and the soil bulk density,total porosity,saturated water holding capacity,organic matter,total nitrogen,alkali-hydrolyzable nitrogen and pH did not reach the significant difference level.However,there were significant differences in soil non-capillary porosity and available phosphorus content in 0-40cm.Soil cellulase and polyphenol oxidase,soil field water capacity,capillary porosity and available potassium were significantly different in 0-20cm and 20-40cm soil layers,respectively.(3)the vertical variation of soil profiles of the two forest types was similar,which showed that the soil bulk density and capillary porosity of bamboo forests increased with the increase of soil depth,while the other soil properties decreased with the deepening of soil layer.The contents of soil organic matter,total nitrogen,available phosphorus and available potassium were significantly different,and the other soil indexes of Chinese fir forest decreased with the deepening of soil layer except soil bulk density,among which the contents of capillary porosity,organic matter,total nitrogen and available potassium were significantly different.(4)soil organic matter content,cellulase activity,total porosity,actinomycetes number and soil bulk density are the main control factors of soil fertility,and soil organic matter and cellulase have strong direct or indirect effects on each other;Soil total porosity was indirectly affected by capillary and non-capillary porosity;actinomycetes were mainly affected directly or indirectly by cellulase and total nitrogen;soil bulk density was mainly affected by sucrase cellulase amylase and other factors.The order of soil fertility of two forest types in Dagang Mountain was Chinese fir forests>bamboo forests.