The Law Of Change On Spatial Structure And Soil Chemical Properties’ Latitude Zonal Change Of Forest In Daxing’an Mountains

Daxing’an mountains’ forest has undergone high intensity harvesting in the 1930s to the 1990s,and since 1998,the government has implemented "natural forest protection projects".The purpose of this paper is to explore the restoration of forest in the Daxing’an mountains since the "natural forest protection projects" was implemented.According to the Daxing’ an mountains latitude characteristics,we take the south of the Daxing’an mountains SaiHanWula National Nature Reserve,central area of WuChaGou Forest Farm and north section HanMa National Nature Reserve as the sample,and set up the sample of 6hm2,8.8hm2,8hm2.The study on the spatial structure and the zonal changes of soil chemical properties of the three plots were carried out by field survey and laboratory experiment.This article selects three parametersthree of spatialstructure parameter,named mingling intensity,neighborhood comparison and uniform angle index.and selects soil chemical properties of PH value,organic matter,total efficiency and available N,P,K.Results show that:1)The forest types of Daxing’an mountains were deciduous broad-leaved forest,coniferous and broad-leaved mixed forest and coniferous forest from south to north.2)The mingling intensity of forest in Daxing’an mountains is poor,and different tree species’ isolation is low.The phenomenon of the same species grow together is obvious.3)The dominant species is white birch in SaiHan Wula,The dominant species are larch in WuChaGou and HanMa.There was more difference in size differentiation.4)The forest of Daxing’an mountains are homogeneous distribution,and WuChaGou ditch is closest to random distribution.5)The soil of Daxing’an mountains is acid,and gradually increased from south to north.The acidic reduced with the rise of the depth of soil.Other nutrient contents are gradually increased from south to north,and reduced with the rise of the depth of soil.6)Organic matter,K element and spatial Structure has a significant relationship.