晋西黄土区蔡家川封禁流域植被演替规律

黄土高原地区由于强烈的水土流失，生态系统处于极度退化的状态，探讨该地区植被自然恢复演替过程中植物多样性的变化规律，对于指导该地区的人工植被建设具有重要的理论价值与实际意义。采用样线与样方相结合的方法，对晋西黄土区蔡家川封禁流域植被的自然恢复及分布规律进行调查；采用聚类分析和演替分析方法，研究了该流域植物群落类型与演替过程。研究结果表明，随着植物群落的演替，流域植被总的覆盖度大幅度增加，物种多样性增加，流域现为该地区的顶级群落-以油松为建群种的植物群丛所占据。

Vegetation Succession of Caijiachuan Closed Watershed in the Loess Plateau of Western Shanxi

Because of serious soil erosion, the ecosystem in the loess plateau is in an extreme degradation condition. There are important theoretical values and practical meanings to disscus the change of plant diversity during natural recovery process of vegetation succession. The natural recovery and distribution pattern were investigated in Caijiachuan closed watershed in the loess plateau of western Shanxi using line transect method and sampling plot method. Based on hierarchical cluster analysis and succession analysis, the present paper deals with community types and community vegetation succession. The results show that vegetation cover degree of watershed and species diversity increased greatly along the succession process. The major plant association is one whose dominant species is Pinus fabulaeformis, as climax biotic community of this area.