Assessment Of Frorest Naturalness In Chang-Zhu-Tan Region

Sustainable development of the forest is the goal of the forestry development nowadays. The important way to achieve sustainable development of the forest is close-to-nature forest management. Natural disturbances and human-caused disturbances widely exist in present forest, which is different from the nature condition. It can describe the station of present forest objectively by evaluating the forest naturalness value, and it can provide the theory for more scientific way of forest management. This paper constructed an evaluation system for the forest naturalness in Chang-Zhu-Tan Region, which based on the fifth review data of forest resources inventory in Hunan. This paper selected more critical factors to evaluate the forest naturalness in Chang-Zhu-Tan Region, and the main result is as follows:(1) Based on data from the continuous forest inventories (CFI),14indicators was preliminary chosen from community structure, community vitality and interference. Based on the method of correlation analysis, principal component analysis and etc.,11indicators were chosen to evaluate the forest naturalness in the Chang-Zhu-Tan Region. These indicators included vegetation coverage, shannon wiener index, number of diameter classes, community structure of forest, the proportion of native species, canopy density, stand volume, number of young tree, mortality volume,felling volume, origin.(2) The qualitative index and quantitative index of the forest naturalness evaluation index were processed in quantity, while the quantitative index and the classes of naturalness were divided based on normal distribution and equidistant method. We have obtained the weight vectors of forest naturalness evaluation as U=(0.04720.12560.09540.08070.05730.07620.11810.08440.08090.10680.1274), which calculated using analytic hierarchy process method.(3) The evaluation result of forest naturalness shows as follows:in322plots, near natural plots account for1.86%, semi-natural account for23.91%, far natural account for29.81%, near artificial account for30.75%, artificial account for13.66%. The result in Changsha is:the percentage of far natural is the largest, followed by near artificial, semi-natural, artificial, near natural. The result of ranks in Zhuzhou is:semi-natural, near artificial, artificial, far natural, near natural. The result of ranks in Xiangtan is:far natural, near artificial, semi-natural, artificial, near natural. Overall, near artificial plots account for the largest proportion, followed by far natural, this shows that the level of forest naturalness in the Chang-Zhu-Tan region is lower than far natural.(4) The main reasons influence the forest naturalness in the Chang-Zhu-Tan region are as follows:First, the forests in the study areas have been disturbed artificially or naturally in some degree. Second, single and simple structured artificial pure forests are the main vegetation types, while complex structured mixed forests which have diversified tree species and strong ecological service function were less distributed. Third, shelter forests are based on conifer, which are more vulnerable to natural disaster than broadleaf dominated timber forest. Fourth, young forests and near-mature forests, which is mainly immature artificial forest, account for a large proportion. The overall level of the forest naturalness has been influenced.