The Upper Broadleaf And Lower Bamboo Mixed Model Effect On Soil Nutrients

The forest types of bamboo are varied,according to the stand composition can be divided intotwo categories: pure forests and mixed forests,mixed forest can be divided into individuals mixedand patch mixed,the object of this page is the one of the patch mixed type that broad-leavedforest on the upside and pure bamboo forests on the downside.According to the throw ratio of the upper broad-leaved forest in the proportion of the entireslope,this paper have chosen three types of bamboo forests that with broad-leaved forest on itsupside and one type of pure stand of bamboo forests as comparison.,the projection ratio of eachtype is32.17％,28.35％and25.22％.We have mainly studentied the function relation betweensoil nutrients and some independent variables, the main conclusions are as follows:1. Upper broad-leved forest had no significant effect on bamboo forest soil element content,but had significant effect on trace element contents.(1) Total nitrogen, total phosphorus, totalpotassium in four types of bamboo forest soil have no significant difference; various types ofbroad-leaved forest soil total nitrogen, total phosphorus, total potassium were also no significantdifference; the upper broad-leaved forest total nitrogen content in type I, II, III were significantlyhigher than its lower bamboo forest;(2) Various types of upper broad-leaved forest soil availablenitrogen, phosphorus, potassium content were less than its lower bamboo forest; the same slopesoil hydrolysis of nitrogen, phosphorus, potassium content in different types of bamboo forestwere no significant difference;(3) Various types of soil total manganese, boron, copper, total ironand zinc content had no significant difference;(4)The soil avaible boron and zinc content inbamboo forest were less than broad-leaved forest soil;type I, II, III avaible boron and zinc contentwere higher than the Type IV, typeI, II, III soil avaible boron and zinc content had no significantto slope differences; the soil avaible boron and zinc content in type IV upside were significantlylower than the downside slope;(5)The orde of the scores of the soil fertility (integrated fertilityindex, IFI) as follows: type I (0.256)> type II (0.254)> type III (0.249)> Type IV (0.241).2. The throw ratio, slope, soil depth,were the main factors on soil available boroncontent,the throw ratio, the vertical distance between the bamboo forest and broad-leaved forest,pH and soil depth;by principal component analysis, seven factors owned by three principalcomponents, the first principal component can be seen as a reaction of the throw ratio and pHfactor, the second principal component can be seen as the response of soil depth and organicmatter content factor, the third principal component is the reaction distance factor.3. As the improvement of the proportion of broad-leaved forest, productivity ofPhyllostachys heterocycal Forest has increased significantly:the order of mean diameter at breastheight of each type was:I (10.330cm)> II (10.232cm)> III (9.769cm)> IV (9.103cm), the type I,II, III were increased13.79%,12.40%and7.32%than type IV.