Study On The Relationship Between Growth And Site Factors Of Pinus Tabulaeformis In Chaoyang Area

The sand-dust storm happens frequently and the drought is serious in Chaoyang city,the west of Liaoning Province.The site condition is complex and the site environment is bad,which lead to the low survival rate and preservation rate of afforestation,and they are also the important reasons for blocking the rapid and stable increase of the forest coverage rate in Chaoyang city.Chinese pine(Pinus tabulaeformis)is an excellent species which is resistant to drought and barren,so it has become one of the main afforestation species in this area.In order to improve the ecological environment in this area,and find the correlation between the Pinus tabulaeformis and the site factors,Pinus tabulaeformis in Chaoyang city was taken as the research object in this paper.The data collected from 27643 small classes of Pinus tabulaeformisPlantation in Chaoyang city.Slope direction(X1),slope position(X2),slope(X3),elevation(X4),soil thickness(X5),soil texture(X6)are the independent variables.Principal component analysis and correlation analysis for the principal component of the site factors had been done,which is based on the division of forest.The principal component is used as the new independent variables to check the correlation with the height,diameter and HA volume.At last,this paper determines the main site factors which impacts the height,diameter and HA volume of Pinus tabulaeformis,exploreing the changes of main site factors with the age of the Pinus tabulaeformis in this area,and finds the main site factors which influent Pinus tabulaeformis growth amount in each age class.The main results are as follows:(1)The slope position and soil texture have a great influence on the height of Pinus tabulaeformis;in young trees,the DBH of Pinus tabulaeformis was significantly correlated with the soil condition,but with the increase of stand age,the DBH of Pinus tabulaeformis increased gradually at the altitude and other topographic factors;slope position is the key factor affecting the accumulation of Pinus tabulaeformis in this area.(2)Soil texture and soil thickness is the main effect of site conditions to Pinus tabulaeformis growth of Chaoyang area.The influence of soil factors,especially the soil texture,affects the most for Pinus tabulaeformis in young period.The growth of near the forest and the forest is also closely related to soil conditions.The secondary factors were elevation,slope position and slope direction.While the effect of slope on the growth of Pinus tabulaeformis is not only weak,but also occurs at intervals of individual age.According to the research results above,soil preparation before planting is an effective means to improve the survival rate and survival rate of Pinus tabulaeformis in Chaoyang area.(3)The slope position is another important site factor that affects the growth of Pinus tabulaeformis,and the slope position plays an important role to the growth of Pinus tabulaeformis.(4)Compared with other site factors,the effect of slope on the growth of Pinus tabulaeformis in Chaoyang city is the weakest,and Pinus tabulaeformis can adapt to all kinds of steep cliffs in Chaoyang area,which has great significance to expand the scope of the green mountains.(5)Site factors influence the most obvious and widely for Pinus tabulaeformis ? and ? age in the Chaoyang area,so it is important to strengthen the management of Pinus tabulaeformis Plantation in this period,and it is the effective way to ensure the healthy development of Pinus tabulaeformis to mature.