Department of Ecology and Evolution/Limnology, Uppsala University, Uppsala, Sweden.
ISME J. 2010 Jun;4(6):729-38. doi: 10.1038/ismej.2009.156. Epub 2010 Feb 4.
To understand the mechanisms determining community composition, it is essential to distinctively unravel the importance of local from that of regional processes. In this effort, the mechanisms underlying bacterioplankton community assembly were analysed in eight lakes of short water residence time (WRT) during a four-season sampling campaign. Bacterioplankton community composition (BCC) was determined using terminal-restriction fragment length polymorphism (t-RFLP) on the 16S rRNA gene (16S rDNA) and 16S rRNA. The relationship between similarity in BCC between a lake and its major inlet on the one hand and cell import per cell production rate from the inlet to the lake epilimnion on the other was used as a measure of the importance of cell dispersal (mass effects) for community assembly. Low similarities in BCC between lakes and their inlets were observed even at short WRTs, and the degree of similarity correlated better with the environmental conditions in lakes and streams than with cell import per cell production rates. Thus, mass effects seemed less important for local lake BCC in comparison to environmental habitat characteristics (species sorting). Analyses of 16S rDNA and 16S rRNA community fingerprints yielded similar results, indicating that species-sorting dynamics exerted an equally important effect on both the abundant and active fraction within the studied bacterioplankton communities.
为了理解决定群落组成的机制，明确区分局部过程和区域过程的重要性至关重要。在这项工作中，我们在为期四个季节的采样过程中，分析了 8 个短停留时间（WRT）湖泊中细菌浮游生物群落组装的机制。通过末端限制性片段长度多态性（t-RFLP）对 16S rRNA 基因（16S rDNA）和 16S rRNA 进行细菌浮游生物群落组成（BCC）的测定。一个湖泊及其主要入口之间的 BCC 相似性与入口到湖泊表水层的每个细胞产生的细胞输入之间的关系被用作衡量细胞分散（质量效应）对群落组装重要性的指标。即使在短 WRT 条件下，也观察到湖泊与其入口之间的 BCC 相似性较低，相似性程度与湖泊和溪流中的环境条件的相关性要好于与每个细胞产生的细胞输入之间的相关性。因此，与环境栖息地特征（物种分选）相比，质量效应对于当地湖泊的 BCC 似乎不太重要。16S rDNA 和 16S rRNA 群落指纹图谱的分析得出了相似的结果，表明物种分选动力学对所研究的细菌浮游生物群落中的丰富和活跃部分都产生了同样重要的影响。
