雅鲁藏布江河谷山地灌丛草地区系组成及特征

Composition and Characteristics of Subalpine Shrub-Grass Communities in the Yarlung Zangbo River Valley

为了有效修复日渐退化的雅鲁藏布江中游河谷地区山地植被,采用群落生态学方法对雅鲁藏布江河谷亚高山灌丛草地群落进行了研究分析.结果表明:该区灌丛草地群落共有维管束植物166种,隶属于47科115属,种类组成较为丰富,属内种系相对贫乏.地理成分及科属分析表明,该区灌丛草地群落具有明显的温带性质;生活型和叶的性质分析表明,该区灌丛草地群落的外貌主要是由落叶全缘叶单叶矮高位芽植物所决定的.群落结构简单,仅有灌木层和草本层.雅鲁藏布江河谷半干旱区亚高山灌丛草地群落的总特点是以地面芽、微形叶、草质叶、单叶、全缘叶为特征,反映了青藏高原高山、寒、旱的性质.在分析灌丛草地群落特征的基础上,还对其生态修复进行了探讨.

The methods of community ecology were used to analyze the subalpine shrub-grass communities in the semiarid Yarlung Zangbo River Valley so as to restore the degenerated mountainous vegetation more effectively. The results showed that there were 166 species of vascular plants of 115 genera and 47 families in the shrub-grass communities. The species in the area were abundant in number, while the species within a genus were relatively scarce. The analysis of geographical factors and plant families and genera demonstrated that the shrub-grass communities were of a distinct temperate nature. The life form and leaf characteristics revealed that the physiognomy of the shrub-grass communities was mainly determined by the nanophanerophytes with deciduous, simple and entire leaves. The structure of the shrub-grass communities was relatively simple and could be divided into a shrub layer and a herb layer. The subalpine shrub-grass communities in the semiarid Yarlung Zangbo River Valley were characterized by the hemicryptophyte, nanophyll, herbaceous, simple leaf and entire leaf, which reflected the alpine, cold and drought characteristics of the Tibetan Plateau. Based on the characteristics of the shrub-grass communities, their ecological restoration was discussed.