半干旱区盐池县四儿滩湿地植被生态位研究

Siertan Wetland Vegetation Niche of Yanchi County in Semiarid Areas

为了解半干旱区湿地植物生态位格局,采用样线法对宁夏自治区盐池县四儿滩湿地湿生带、交错带和旱生带的植被生长状况进行了调查,分析了各物种的重要值,并运用Levins生态宽度指数及Pianka生态位重叠指数对植物生态位宽度及生态位重叠进行了计量。结果表明,湿生带以耐盐碱的盐爪爪(Ka-lidium foliatum)为绝对优势种,其重要值、生态位宽度远大于其它物种。说明湿生带盐碱度太高,只有极少数物种可以生存。在交错带和旱生带,重要值和生态位宽度均是赖草(Aneurolepidium dasystachys)最大。旱生带与交错带相比,大部分物种的生态位宽度有所提高,说明旱生带更适宜植物生长。同时,分析3带的生态位重叠度结果表明,生态位宽度与生态位重叠度之间并不存在直接的线性关系。

In order to find the wetland vegetable niche pattern in semiarid grassland region,vegetation growth in wet zone,interlaced zone and drought zone of Siertan wetland,Yanchi County in Ningxia Hui Autonomous Region was studied with transect lines.The importance value,niche breadth and niche overlapping were measured by means of importance value,Levins niche breadth and Pianka niche overlapping indexes.The results showed that,saline tolerance of Kalidium foliatum was absolutely dominant in wet zone with the important value and niche breadth far greater than other species.Because the saline and alkaline of wet zone was too high,only a few species could survive.The importance value and niche breadth of Aneurolepidium dasystachys was the largest in interlaced zone and drought zone.Compared with interlaced zone,niche breadth of most species was improved in drought zone,suggesting that drought zone was more suitable for plant existence.There was not a direct linear relationship between niche breadth and niche overlapping based on niche overlapping results of three zones.