| Based on the investigation, to establish a suitable health assessment index system for Pinus tabulaeformis stand in Xiaolongshan area, to provide theoretical basis and methods for health management and early warning. 31 plots were selected in Longmen, Liziyuan, Mayan and Baihua forest farm. Species composition, space structure and soil properties were analyzed with community investigation method. The description of stand characteristics of more than 40 indicators was analyzed by using principal component analysis method, Indicators with higher relationship was removed, and 30 indicators were selected finally. Using analytic hierarchy process assessed the forest status from five aspects, the productivity, structure, services, resistance and soil. Discussed the impact of the main factors of regional forest health, and the results indicated that:1.After correlation, principal component analysis of health assessment indicators of Pinus tabulaeformis, finally selected 30 indicators from vitality, structure, soil, services, and resistance, including net productivity, tree height growth, vitality, total height of the seedling, Seedling density, richness of seeding ,tree, shrub layer and herb layer, herb layer evenness, canopy overlap,shrub and herb cover, crown ratio, diameter structure, bulk density, capillary porosity, Ph, total NPK, organic, carbon fixation,oxygen release,soil and water conservation, and disturbing intensity and pests and diseases.2.Through the main structural component of the primary targets to reduce the dimension, determine four principal components, species diversity, density, coverage, and structure. Stand structure was evaluated by the methods of comprehensive evaluation function of the principal component, and the results showed that the average health score of natural Pinus tabulaeformis stand structure was 0.6396, plantation was 0.2156, and the structure of natural pine forests was better than plantation.3.Studied on the different types of Pinus tabulaeformis showed that natural health composite index higher than the plantation. Pinus tabulaeformis in different ages, natural composite index was no significant changes with age. In the plantation, the 40-year composite index was higher than 30 years. Studied on the different densities of 30 years old pine plantation showed that the health index had the basic trend of increased and decreased with density. The pine health index was higher in 1100~1733 N/hm2, but was low in 3773 N/hm2, which indicated that 1100~1733 N/hm2 was the suitable density for maintenance of stand structure.4.Studied on the heath status of Pinus tabulaeformis forest in Xiaolongshan Mountain, survey of 31 plots in natural forests in the health plots were 5, Plantation was 0; there were 7 natural plots and 7 plantations in sub-health state; 1 natural plot and 11 plantations in unhealthy state. In a word, the average natural health index was 0.5077, in the sub-health state. The average health index of plantation was 0.3671, in unhealthy state.5.The mian factor infulced on Xiaolongshan Pinus tabulaeformis health was illegal logging and grazing in natural forests and in platation the stand density was too high and the structure was not in good state.
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