Research On Close-to-nature Management Technology Of Pinus Koraiensis

Koreanpine mixed forest is the zonal climax community in northeast of China owing to its composition and structure with stable and high yield. In last200years, the Koreanpine mixed forest has encountered several large-scale artificial destructive interferences, making the zonal climax community lose balance, retrograde succession emerge, forestry and ecological environment exacerbate, species amount and forest productivity decrease, and natural desasts occur more frequently. After the PRC has established, people have planted a lot of pure forests of Koreanpine in this area aiming at resuming the precious Koreanpine forest resource promptly. However, the soil fertility has declined because of planting pure Koreanpine continuously, soil’s physical and chemical properties have degraded, nutrient cycling has lost its order, the resistance against natural calamity such as illness and insect has declined, The economic, social and ecological function of forest ecosystem has been degenerating day by day.The research has analyzed the forest structure of Koreanpine plantations in Da Nangou from four aspects (the tree species composition, the structure of diameter, the structure of tree height and canopy feature. The results showed:the diameter distribution curve of40a and18a Koreanpine plantation showed a single mountain-like curve distribution in the region, the diameter classes of trees are mostly concentrated in the middle-class, the small diameter and large diameter trees are less, larger stand density, the canopy overlap, which makes canopy occurring severe differentiation, the pressed wood of under the canopy due to lack of enough light and poor growth, on the verge of death; bad understory light transmittance, thick ground cover, cause adverse natural regeneration of understory; overlapping of forest canopy of advantage wood lead the trees to undergo the constraints of sunlight, water and nutrients, growth reducing, intensified competition of trees, so large diameter class trees are fewer. Overall, the stand volume of per unit area of Koreanpine forest is small and forest structure is bad. The study also analyzed the understory updates features of Koreanpine plantations, the results showed that the young trees and understory updates density of Koreanpine plantations of40a and18a raw is small, and the update status of near mature and young stands of Koreanpine forest is bad.Through the analysis of stand structure and understory renovation characters of Koreanpine plantations in the Liaodong mountainous area, the study formulated a intimate natural management transformation measures with suitable. Against the stand structure feature of Koreanpine forest of40a and18a born, respectively designed different types of stand development:Koreanpine-Betula albosinensisl Cyclobalanopsis glauca mixed coniferous and broadleaved forest and Koreanpine-Oaks mixed coniferous and broadleaved forest, and developed the relevant business technical indicators on this basis. According to the area Koreanpine plantation site conditions, forest growth conditions and transformation goals, the study formulated regeneration patterns of natural regeneration and supplemented by artificial regeneration. The research took Near-natural forestry theory as guidance, by the near-natural operating transformation trials in Koreanpine plantations in Da Nangou of Huanren, obtained key transformation measures and business technical indicators to improve the business technical level of Koreanpine mixed forest.