青海湖地区芨芨草群落主要种群分布格局研究

以青海省三角城种羊场地区典型的芨芨草草原为研究对象,采用相邻格子样方法取样,应用方差/均值比率法、负二项参数(K);扩散系数(C);C ass ie指标(CA);丛生指标(I)和聚块性指标(m*/m)等指标,比较了青海湖地区围栏内、外芨芨草群落主要种群的空间分布格局。结果表明,围栏内芨芨草群落优势种群的空间格局除多裂蒲公英为随机分布外,其余均为聚集分布;围栏外除西伯利亚蓼外,其余种群也全部为聚集分布,而且围栏外种群的聚集强度大于围栏内。物种的这种分布格局主要与物种本身的生态和生物学特性有关。

Distribution Patterns of Major Populations in Achnatherum splendens Communities of Qinghai Lake Area

The spatial distribution patterns of major populations in the Achnatherum splendens communities inside and beyond fence limits were comparatively studied by taking typical A.splendens grassland in Sanjiaocheng breeding sheep farm of Qinghai Province as the study subject,sampling by contiguous quadrat grid and making use of such indexes as variance/mean ration,negative binomial parameter,dispersion coefficient,Cassie index,clumping index,and patchiness index.The results showed that in the A.splendens communities inside fence limits all the dominant populations but Taraxacum dissectum population,which presented a random spatial distribution,had an aggregated spatial distribution;in the the A.splendens communities beyond fence limits,all the populations but Polygonum sibiricum population showed an aggregated distribution,the aggregation degree of the populations beyond fence limits was higher than that inside fence limits.This distribution pattern of the species is mainly related to their ecological and biological characters.