Researches In The Evaluation Of Urban Forest Naturalness And Operation Countermeasures In Wuhan City

Forest naturalness is the degree of the native state of forest ecosystems keeping or human disturbance, an important indicator reflecting the quality and ecological conditions of forests, and it is one of the selection criteria of the national forest city. But the evaluation of forest naturalness in our country is still at the exploratory stage, or there is no uniform system of the indicators. This study based on influential factors of forest naturalness, combining the relevant factors of forest management inventory, selects factors for forest naturalness evaluation and construct quantitative evaluation index system and evaluation model of urban forest naturalness. Making forest management inventory informationas data source, on the basis of quantitative evaluation index and determine weight, evaluates and analyses the forest naturalness of the Wuhan City and its seven districts. Put forward the operation countermeasures of urban forest in Wuhan City, in order to provide the basis for close-to-nature management and sustainable development of urban forest in Wuhan City. The main findings are as follows:(1)According to indexes of forest management inventory, selecte forest category, stand origin, species compositon, stand level, stand age group as the main factors for the evaluation of forest naturalness to construct quantitative evaluation index system of urban forest naturalness . Building weight value, forest naturalness formulas of subcompartments and regions, criteria for city forest natureness grading. This study make full use of existing data resources to evaluate the forest naturalness, can not only cost savings, and the resolution of forest naturalness evaluation restriction for difficult to investigate large area.(2)The naturalness value of Wuhan is 0.44. In accordance with the order of the naturalness value of urban forest in seven districts were: Huangpi District(0.55), Caidian District(0.42), Jiangxia District(0.41), Hongshan District(0.35), Xinzhou District(0.29), Dongxihu District(0.25), Hannan District(0.24). The area of medium grade(IIIgrade)and lowest grade( I grade)forest is the biggest, respectively, accounted for 35.29%, 34.28%; The area of II grade forest accounts for 27.97%; The area of IV grade and highest grade(V grade)forest is the smallest, accounted for 2.46%. It can clearly be seen that the naturalness of urban forest in Wuhan is at a low level and the distribution of naturalness grade of urban forest in seven districts is inequality.(3)The main factors impact of forest naturalness of Wuhan City are as follows: The forest of natural regeneration is less, the mixed forest is serious shortage, the half-mature and young stand are dominant. Except of Xinzhou District, the main factors impact of forest naturalness of districts are different from Wuhan City as follows: The main factors of Jiangxia and Hongshan District is the low of the mixed forest; The main factors of Dongxihu District is the lack of forest for protection and special use, the forest of natural regeneration and multi-layer structure, the mixed forest; The main factors of Hannan District is the shortage of forest for protection and special use, the forest of natural regeneration and multi-layer structure, the mixed forest and near mature, mature, over mature stand; The main factors of Caidian District is poverty of the forest of natural regeneration and the mixed forest; The main factors of Huangpi District is the scarcity of the mixed forest and near mature, mature, over mature stand.(4)In accordance with the naturalness of forest status of Wuhan City made the objectives and principles of close-to-nature management in Wuhan City. focused on different districts, different naturalness grade stands, different forest types and community types, bring forward the operation countermeasures for close-to-nature management.