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.