长江中上游地区马尾松水保林类型研究

A Study of Masson Pine Forest Types for Soil and Water Conservation in the Upper and Middle Reaches of Yangtse River

长江中上游地区马尾松林的分布非常广泛．根据调查资料，采用定性与定量分析相结合的方法，将这一地区的马尾松水保林分为2个类型组：纯林和混交林．再根据林分的乔木层和灌本层中优势种的不同，将水保林分为23个类型．然而从植被的观点看，他们均属于不同演替阶段或同一演替阶段不同生境的产物，且一般是不稳定的．

The distribution of Masson Pine forest is very wide in the upper ana middle reaches of Yangtse River. Based on the investigation data and using the combined methods of qualitative and quantitative analyses, we divided the forests of this area into two type groups:the pure forest and the mixed forest. Then according to the difference of dominant plants at arbor and shrubbery layers of the stand, we sub--divided the two groups into 23 types. Nevertheless, from the viewpoint of vegetation succession,they are all poducts belonging to distinct succession stages or to different habitats of the same stage and generally, are unstable.