Study On The Tree Diversity And Stand Stability Of The Broad-leaved Korean Pine Forest On The Northern Slope Of Changbai Mountain

Study area is set in Lushuihe Forestry Bureau which is Located in the north slope of Changbai Mountain. By setting11pieces of original broad-leaved Korean pine forest and its fixed sample as the research object, focuses on:different degree of interference of broad-leaved Korean pine forest and its secondary forest tree community structure and the influence of tree species diversity; Changes in tree community structure and tree species diversity variation in different age stages of secondary forestThe main conclusions are as follows:(1) Moderate interference can increase the number of small diameter trees in original broad-leaved forest, serious interference will destroy forest diameter class structure. Secondary forest once suffered disturbance, there will be a dramatic reduction in the number of small trees, and trees diameter class structure will be severely damaged. Tree community height class structure of the original broad-leaved Korean pine forest is the most abundant, each layer of forest proportion mixed reasonable. Tree community height class structure is simple and single storey in Secondary forest. With the increase in age, tree community height and diameter class structure changes to complex and diverse, height class structure and diameter class structure of near mature forest was better than the young forest and middle-aged forest.(2) The dominant tree species number of the original forest (6species) less than secondary forest(8-10species). But the original forest has bad update status; main tree species saplings abundance is far less than secondary forest. Light disturbance can increase the number of young trees and dominant tree species in the original forest dominant, severe interference will reduce the dominant tree species in forest, and increase the advantage of species dominance. With the age increasing, dominant tree number increase, the dominance of he dominant species changes at the opposite trend.(3) Index of forest species diversity and evenness index are increased than the original forest, ecological dominance decreased. DBH diversity index and species abundance of secondary forest, is less than the original forest, Ecological dominance is higher than the original forest. Interference will lead to the decrease of forest tree species diversity, Disturbance the greater, reduce the greater. The relationships of the interference degree and community DBH diversity are more complex, and need further study. The species diversity index and evenness index, DBH abundance index and DBH diversity index increased with stand age increased, and Species dominance and DBH dominance decreased.(4) The stability study of samples shows that, Stability of the original forest is higher than that of three secondary forest types. The original broad-leaved Korean pine forest without the interference has the highest stability. Cutting Disturbance reduces the stability of the original forest, but increased the stability of secondary forest. The relationship between cutting disturbance and the stability of stand is very complex, need further study.