草甸草原与典型草原及其过渡带群落物种组成比较

Comparison of Community Species Composition Among Meadow Steppe,Typical Steppe and Transition Zone

以呼伦贝尔典型草原、草甸草原及其中间的三条过渡带为研究对象,采用野外群落调查法,设置草甸草原(A)、过渡带(B1、B2、B3)和典型草原(C)5个试验样地,每个样地随机取15个1m×1m的样方,测定地上生物量、物种组成等,分析群落重要值、多样性指数、群落相似性指数等。结果表明:(1)由草甸草原→过渡带→典型草原样地内物种数逐渐减少,且建群种重要值波动较大,逐渐出现寸草苔和蒿类植物;(2)每两个样地间相似性依次为过渡带B1与草甸草原A>过渡带B3与典型草原C>过渡带B2与典型草原C>过渡带B3与草甸草原A>过渡带B1与典型草原C>过渡带B2与草甸草原A;(3)各样地Simpson多样性指数(D)、Shannon-wiener多样性指数(H')和Margarlef丰富度指数(Ma)最高的群落均为草甸草原样地,最低的群落均为典型草原样地,而Pielou均匀度指数(Jp)最高的群落为过渡带B3样地,最低的群落为过渡带B1样地。

The typical steppe,meadow steppe and three transition zones in the middle of Hulun Buir were taken as the research objects,using the field community survey method,set up five experimental sample plots,the meadow steppe(A),typical steppe(C)and transition zone(B1,B2,B3),randomly took 15 quadrats of 1m×1m from each plot,aboveground biomass and species composition were measured,the important value、diversity index and community similarity index were analyzed.The results showed that,(1)From the meadow steppe to the transitional zone and then to the typical steppe,the species decreased gradually,and the importance value of the constructive species fluctuated greatly,Carex duriuscula and Artemisia gradually appeared;(2)The similarity between each two sample plots were:B1 of the transition zone and the meadow steppe A>B3 of the transition zone and the typical steppe C>B2 of the transition zone and the typical steppe C>B3 of the transition zone and the meadow steppe A>B1 of the transition zone and the typical steppe C>B2 of the transition zone and the meadow steppe A;(3)The species diversity showed:the highest value of the Simpson diversity index(D),Shannon-wiener diversity index(H′)and Margarlef richness index(Ma)were appeared in meadow steppe,and the lowest were in typical steppe samples;But the Pielou uniformity index(Jp)was the highest in the transition zone B3,and the lowest in the transition zone B1.