石羊河下游绵刺群落结构和物种多样性特征

在对石羊河下游绵刺群落野外实地调查的基础上,对群落结构和物种多样性特征进行了分析。结果表明:石羊河下游绵刺群落由10科27属30种植物组成,单科单属种占绵刺群落植物种类的50%,科属组成分散,植物种类单一。灌木的密度和盖度明显大于多年生草本和1年生草本。群落密度山间谷地最大,沙砾质荒漠最小;群落盖度沙砾质荒漠和山间谷地相差不大,山前洪积扇地最小。绵刺为群落优势种,在沙砾质荒漠上密度和盖度最大,在山前洪积扇地密度和盖度最小。绵刺群落在山前洪积扇地和山间谷地物种比沙砾质荒漠相对较丰富。从物种多样性特征来看,绵刺群落在山间谷地上分布的绵刺群落相对稳定,在山前洪积扇地和沙砾质荒漠的分布稳定性较差。

Community Structure and Species Diversity Characteristics of Potaninia mongolica Community in the Lower Re a-ches of Shiyanghe River

We studied the community structure and species diversity characteristics of Potaninia mongolica community in the lower reaches of Shiyanghe River .A total of 30 species belonging to 27 genera in 10 families were identified in the surveyed plots, and the species were unitary and the families and genus are of scattered composition .The community density and coverage of shrub plants are obviously greater than those of perennial and annual herb plants .Community density is the maximum on the mountain valley , but the gravel desert is the minimum .There is no significant difference between moun-tainous valley and gravel desert in the community coverage , and the alluvial fan is the minimum .The species richness for Potaninia mongolica community is higher in the alluvial fan and mountainous valley than that in the gravel desert .The spe-cies diversity characteristics are more stable in the mountainous valley than that in the gravel desert .