岷江上游干旱河谷区植被特征与多样性研究

岷江上游干旱河谷区特征与植物多样研究表明：1）植物种类贫乏，有明显的重点科；并以的豆科Leguminosae、菊科Compositae、蔷薇科Rosaceae和禾本科Graminea等被子植物种类较大。2）对阴、阳坡不同海拔灌丛植被α多样性的的测度表明，各样地灌丛群落灌木和草本的物种多样性H与丰富度S、均匀度E成正相关关系，而与优势度D呈相反关系；植物群落物种α多样性指标在阴坡随海拔升高表现出明显的直线上升增加趋势，阳坡呈现出中间低两边高近似“U”型的海拔梯度格局；草本具有和灌木多样性指数相似的海拔梯度格局。3）低海拔梯度和高海拔梯度的灌丛植物种类和群落生境有较大的差异；随着海拔的升高，相似性减小，物种更替速率增大，灌丛群落的β多样性具有明显的变化规律。

A Study of the Vegetation Characteristics and Diversity of the Arid Valley in the Upper Minjiang River

Researches were conducted on plant species diversity in arid valleys of in the upper Minjiang River and the results showed that： 1 ）Plant species were poor. There were obviously important families, including Leguminosae, Compositae, Rosaceae and Graminea. 2）From the α diversity of shrub communities at different elevation gradients, the diversity of shrub and herb species in shrub communities was positive linear correlation with richness and evenness indexes, and was the opposite linear correlation with dominance;The α diversity increased with the rising of the elevation, which showed the U-type on south facing slope and linearity increased on north facing slope. Herb diversity showed a similar trend with shrub diversity. 3）There were obvious differences in species of shrub and community habitat. Moreover, the similarity decreased and the species succession accelerated and the βdiversity of shrub communities had an obviously changing law with the rising of elevation.