岷江上游杂谷脑河干旱河谷植被特性研究

岷江上游杂谷脑河干旱河谷属干暖河谷,该区干旱河谷灌草丛植被分布于河面以上海拔高度2 000m以下的河床两侧山坡范围内,不同种类的灌丛分布断续,主要呈随机分布和集群分布,很少呈均匀分布.灌木基本上为落叶种类,为适应恶劣的环境,灌木表现出一系列的趋同现象,如丛生、根深、叶小、具刺、被毛、低矮或匍匐的性状;群落层次和组成结构单一,群落类型具有多样性.该区有维管植物253种,隶属于57科178属,植物种类贫乏,有明显的重点科.种子植物区系以温带成分占优势,与热带成分有紧密的联系.植被具有荒漠化、半荒漠化性质,且程度在加重.

Research on Vegetation Characteristics in Arid Valley of the Zagunao River at the Upper Reaches of the Miniiang River

The arid valley of the Zagunao River belongs to warm-arid valleys at the upper reaches of the Minjiang River, Its vegetations distribute on the mountain slope of both sides of the Zagunao River below the altitude of 2 000m , The different species scrubs distribute discontinuously, mainly in random and in gathering distribution, but a little proportion in even distribution. Shrubs are mostly deciduous species. They demonstrate a series of similar phenomenon such as growing in clumps, deep root, small leaf, having splinter, covered hair, short and creep growth in order to adapt to bad environment. The layer, composition and structure of communities are all very simple, and community types are diversity. The region has 253 species of vascular plants, belonging to 178 genera and 57 families. Plant species are quite poor; they have obvious big families. In seed plant flora, the floristic composition is dominated by the temperate elements, which have tight relation to tropic elements. The vegetations have a tendency of eremcan and semi-eremcan, which is getting more and more serious.