Species prevalence across the landscape is related to their local abundance, which is a result of deterministic and stochastic processes that select organisms capable of recolonizing sites where they were once extinct, a process known as the rescue effect. The occupancy-frequency distribution (OFD) describes these patterns and has been extensively used to understand organism’s distribution but has been poorly tested on microorganisms. In order to test OFD on freshwater bacteria, we collected data from 60 shallow lakes distributed across a wide area in southeastern Brazil, to determine the bacterial operational taxonomic units (OTUs) that were present in all sites (core) and at only one site (satellite). Then, we analyzed the spatial abundance distributions of individual OTUs to understand the influence of local abundances on regional occupancy patterns. Finally, we tested the environmental factors that influenced occupancy and abundance. We found a significant bimodal OFD for freshwater bacteria using both OTUs (97% clustering) and amplicon sequence variants (ASVs, unique sequences), with 13 core OTUs and 1169 satellite OTUs, but only three core ASVs. Core organisms had a bimodal or gamma abundance distribution. The main driver of the core community was pH, while nutrients were key when the core community was excluded and the rest of the community (mild and satellite taxa) was considered. This study demonstrates the close relationship between local environmental conditions and the abundance and dispersion of microorganisms, which shapes their distribution across the landscape.

整个景观中的物种流行与它们的局部丰富度有关，这是确定性和随机过程的结果，该过程选择能够重新定居曾经灭绝的地点的生物，这一过程称为救援效应。占用频率分布（OFD）描述了这些模式，并已广泛用于理解生物体的分布，但对微生物的测试很差。为了测试淡水细菌的OFD，我们收集了分布在巴西东南部广大地区的60个浅湖的数据，以确定在所有地点（核心）和仅一个地点存在的细菌操作分类单位（OTU）（卫星）。然后，我们分析了各个OTU的空间丰度分布，以了解局部丰度对区域占用模式的影响。最后，我们测试了影响占用和丰度的环境因素。我们发现了使用OTU（97％聚类）和扩增子序列变体（ASV，独特序列）的淡水细菌的重要双峰OFD，具有13个核心OTU和1169个卫星OTU，但只有三个核心ASV。核心生物具有双峰或伽马丰度分布。核心社区的主要驱动力是pH值，而排除核心社区和其他社区（轻度和人造卫星）时，营养是关键 我们发现了使用OTU（97％聚类）和扩增子序列变异体（ASV，独特序列）的淡水细菌的重要双峰OFD，具有13个核心OTU和1169个卫星OTU，但只有三个核心ASV。核心生物具有双峰或伽马丰度分布。核心社区的主要驱动力是pH值，而排除核心社区和其他社区（轻度和人造卫星）时，营养是关键 我们发现了使用OTU（97％聚类）和扩增子序列变异体（ASV，独特序列）的淡水细菌的重要双峰OFD，具有13个核心OTU和1169个卫星OTU，但只有三个核心ASV。核心生物具有双峰或伽马丰度分布。核心社区的主要驱动力是pH值，而排除核心社区和其他社区（轻度和人造卫星）时，营养是关键考虑了（taxa）。这项研究证明了当地环境条件与微生物的丰富和分散之间的密切关系，这决定了它们在整个景观中的分布。