Close-to-nature Analytic And Management Pattern Of Headwater Protection Forest In The Watershed Of Miyun Reservior In Beijing

The management of headwater protection forest is of much significante for protecting our national water resources and ecological environment safety.However,current studies on the management theories and method system for watershed forests are weak.Morever,some of those studies are single-faceted and difficlult to direct the watershed forest management practice comprehensively.Lacking in the necessary theoretical guidance and the management methods,our watershed forest managements are always too general and extensive without specialized difference from the timber planation management system, these result often in an atrophy and degeneration of the main functions for water conservation.Used typical shelter forest in the watershed of Miyun Reservoir in Beijing as this research object, through the research of site type,forest type and their Close-to-nature degree,analyze the degree of different forest type.According to close to nature forest theory,proposed different management pattern to different close-to-nature degree of forest type,and constructed the objective forest shape,in order to simulate superior structure and function of nature forest.Achieve the biodiversity and ecology stability. Acquire obvious ecological benefits and higher economic profit,and the purpose of sustainable use.On the foundation of invest topography,soil and vegetation of Chaoguan West Ditch,according to the principle of classify site type,establish altitude,slope direction,topography position,soil thickness,soil quality as the predominant factors of classify site type.Under the basis,Chaoguan West Ditch was classified 3 site-type small-districts,5 site-type groups,14 site-types.Analytic the characteristic and problems of main forest type.Take closing,diameter class,seedling quantity,Shannon-Wiener index,evenness index and climax index as parameters to evaluate near-nature-degree of different communities.From the calculation results we can see,Quercus Mongolia forest＞Tilia tuan forest＞Populus davidiana forest＞Pinus tabulaeformis forest＞platycladus orientails forest＞Robinia pseudoacacia forest,that is the Close-to-nature degree of natural secondary forest in successional stages significantly higher than artificial simple forest.Through the division of the Close-to-nature degree of forest and combine different successional stages,put forward four kinds of management pattern.And divided forest management district of study area.Through the study of site classification,distribution characteristics and Close-to-nature degree,as much as possible to select native trees set up the objective forest shape of Chaoguan West Ditch.Proposed a systematic transformation pattern,and provide theoretical basis and practical guidance for transformation and management of forest.