Abstract The need to understand the influence of high-level factors that shape species richness and population size is becoming more important as global biodiversity losses threaten biotic communities. Here we investigate the influence of ecological drift on periphytic diatom community composition in arctic lakes. If community composition is strongly influenced by drift, we hypothesize that (i) alpha diversity will increase with increasing lake size, due to the decreasing influence of drift-mediated local extinction, (ii) beta diversity will be greatest among small lakes and lowest in large lakes, and (iii) relationships between community size and environmental variables will be strongest in large lakes and weakest in small lakes. Analysis was conducted on periphytic diatoms accrued on artificial substrates in 44 shallow, thermokarst lakes over the 2009 growing season. Limnological and hydrological conditions at each site were described and their influence was removed to minimize the confounding effect of environmental heterogeneity. Alpha diversity was not significantly different among the lake sizes. Total beta diversity was significantly higher in the small lakes than the medium lakes. Beta diversity was primarily attributed to turnover, and small lakes had significantly higher turnover than medium and large lakes, while nestedness was not significantly different among lake-size classes. Periphytic diatom community composition and environmental variables were not significantly concordant in any lake-size class. Our results suggest that drift, as related to habitat size, is not a primary driver of periphytic diatom community composition in shallow, thermokarst arctic lakes.

中文翻译：

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生态漂移在构建附生硅藻群落中的作用

摘要 随着全球生物多样性丧失威胁到生物群落，了解影响物种丰富度和种群规模的高级因素的影响变得越来越重要。在这里，我们研究了生态漂移对北极湖泊中附生硅藻群落组成的影响。如果群落组成受到漂移的强烈影响，我们假设 (i) α 多样性将随着湖泊大小的增加而增加，由于漂移介导的局部灭绝的影响减小，(ii) β 多样性在小湖泊中最大，在(iii) 群落规模与环境变量之间的关系在大湖中最强，在小湖中最弱。对44个浅水区人工基质上产生的附生硅藻进行了分析，2009 年生长季节的热岩溶湖泊。描述了每个地点的湖沼学和水文条件，并消除了它们的影响，以尽量减少环境异质性的混杂影响。阿尔法多样性在湖泊大小之间没有显着差异。小型湖泊的总贝塔多样性显着高于中型湖泊。Beta多样性主要归因于周转，小湖的周转率明显高于中大湖，而湖泊大小类别之间的嵌套性没有显着差异。在任何湖泊大小类别中，附生硅藻群落组成和环境变量都没有显着一致性。我们的研究结果表明，与栖息地大小相关的漂移不是浅水区附生硅藻群落组成的主要驱动因素，