Soil Fertility Under Four Forest Stand Types in Low Hills of Eastern Jilin Province

According to the soil fertility data of four main stand types(natural korean larch forest,korean larch plantation,natural mixed coniferous and broad-leaved forest and natural mixed broad-leaved forest)recorded in Jincang forest farm,which is administrated by Wangqing Forest Bureau,Jilin Province,analysis and comparison of soil physico-chemical properties were carried out,and the fertility of soils in the above stands was further assessed with principal component analysis.The results are as follows:(1)Soil bulk density and soil pH vaule increased while soil water content,cation exchange capacity(CEC)and nutrients content decreased with the soil depth in various degree in different forest stands.(2)Forest stand types had significant effects on some soil as for the chemical properties such as soil CEC,organic matter content,total N and rapidly available K(p0.05),of which the highest soil water content,soil pH vaule,CEC,soil organic matter,total N,total P and total K were found in natural mixed coniferous and broad-leaved forest.(3)The soil fertility assessment with principal component analysis showed that soil fertility for four main forest types is in the decreasing order with natural mixed coniferous and broad-leaved forestnatural korean larch forest korean larch plantationnatural mixed broad-leaved forest.Therefore,close to nature silviculture,timely artificial regeneration and restoration,mixed coniferous and broad-leaved forest construction are suggested to improve the general fertility quality of main forest stand types in the study area.