Effects Of Opening Degree On Growth Of Korean Pine Trees Under Canopy Of Secondary Forest

Korean pine broad-leaved mixed forests is the climax community in eastern mountain area of the northeast China, has suffered severe damage, the recovery work of Korean pine broad-leaved mixed forest is urgently needed, in order to quickly and efficiently to secondary forest restoration become nearly climax of Korean pine broad-leaved mixed forest, this paper studies relationship between the opening degree and the Korean pine under canopy growth and its impact factors, in order to find out the relation between the opening degree and the growth of Korean pine, and other factors influence this relationship, so as to further reasonable application opening degree indexes under the forest canopy of Korean pine and broad leaved tree relationship between regulation and promoting forest resumed as soon as possible for nearly climax of Korean pine broad-leaved mixed forest. This article studied the relationship between the growth of the Korean pine and opening degree, and affect the relationship of various factors, including soil bulk density, soil porosity, soil nutrient factors, soil physical and chemical properties such as the upper hardwood tree height, diameter at breast height, tree species of deciduous tree, such as growth factor, through the investigation and study of each factor, according to the comprehensive analysis of the results, the research shows that:(1) Slope has influences on Korean pine growth.Average DBH of Korean pine in Shanhe and Maoer mountain has increased by opening degrees in the south, west and north slope. There is the same law in the south and west slope in Fangzheng. the north slope of Korean pine under all levels of the open degree average diameter at breast height was not significant difference directly. When the opening degree is1.0, average DBH of Korean pine is higher than the other opening degrees in east slope in Shanhe and Maoer mountain, it is highest when the opening degree is2.0in Fangzheng.The average height of Korean pine has increased by the opening degrees in south and west slope, it is no significantly directly in north slope in three study sites. Korean pine in Maoer mountain growth better than the other two study sites.(2) After the opening degree regulation and control, high and DBH increment of Korean pine change differently.In the first5years after regulation, the growth of Korean pine has no significant regularity, in age-class Ⅰ, the biggest Korean pine average DBH increment appeared in2007year under the opening degree of1.0, the average DBH has decreased when the opening degrees increasing. In age-class Ⅱ, the biggest Korean pine average DBH increment appeared in2005year under the opening degree of1.5, the average DBH of Korean pine is higher than the control group in the stand. In age-class I, average maximum height of Korean pine increment appeares in2007undre the opening degree of2.0, In2008, tree height of annual growth is less than the other years, In the age-class II, average maximum height of Korean pine appeares in2005year under the opening degree of1.5. After opening degree regulation seven years later, the height and DBH of Korean pine changes regularly, when the opening degree increase, the heighe and DBH increase by it.(3) the relationship between soil nutrients were positively correlated to the growth of the Korean pine, soil physical and chemical properties affecting the growth of Korean pine under canopy.(4) The upper-layer broad-leaved trees have influenced to Korean pine growth. The average height of upper-layer broad-leaved trees are lower than the other two study sites, the average DBH of upper-layer broad-leaved trees are lower than the others in east、west and north slopes in Fangzheng, and in these sites, Korean pine growth better than the other study sites.