风景林景观格局特征分析

Analysis of landscape pattern of scenic forest

以北京市西山试验林场为例,利用林相图和森林资源二类调查资料,从3个等级划分风景林景观斑块类型,并利用GIS软件,分析各级斑块类型的景观格局特征。结果表明:1)风景林自然状态保留程度、游客对风景林的干扰利用特征、林分固有自然属性分别从3个等级影响斑块分维值的高低,也是影响各个等级景观格局的主要驱动因子;2)整个景观过度受制于部分斑块类型,景观多样性不高;3)灌木林地的继续减少,不利于维持景观多样性和生态系统稳定性。针对以上结论提出其在风景林管理中,根据不同等级景观格局驱动因子的特点,采取相应经营措施:对于油松、侧柏、刺槐等比重过大的斑块,可通过调整混交比例、选择适当混交树种等手段,调整斑块类型间的分配比例;对于灌木林斑块,特别是立地条件极其恶劣、造林难以成功的地段,应适当保留,有利于不断提高景观多样性和生态系统的稳定性。

The paper takes the experimental forest Farm of Beijing West Mountain as an example to study the scenic forest landscape patch type and pattern. Firstly, the scenic forest landscape patches were classified by three levels using the stock map and information of forest resource survey. Then the pattern of each landscape patch type was analyzed based on the application of GIS. The following conclusions were made based on the analysis： 1） The fractal dimension was influenced by three factors from three levels separately. The factors are nature closeness of patterns, using characteristics of victors to the scenic forest, natural attribute of stand. And they are main driving forces for the landscape pattern too. 2） The whole landscape pattern was over confined by some patch types, which results in low landscape diversity. 3） The continuous decreasing of shrubbery makes it difficult to keep scene diversity and the stability of ecology system. Finally, the main methods to solve the problems were proposed based on these conclusions. 1） According to the characteristics of the driving forces for the landscape pattern, the corresponding measures in its management should be taken. 2） To those patches with high proportion of Pinus tabulaeformis、Platycladus orientalis and robinia pseudoacacia, it should be regulated their mix proportion, and chosen proper mixed trees, thus its allotment of patch patterns adjusted. 3） Reserving the shrubbery patches, especially those have leanness site condition, it is advantageous to raising the scenic diversity and biodiversity.