Microbial spatial distribution has mostly been studied at field to global scales (i.e., ecosystem scales). However, the spatial organization at small scales (i.e., centimeter to millimeter scales), which can help improve our understanding of the impacts of spatial communities structure on microbial functioning, has received comparatively little attention. Previous work has shown that small-scale spatial structure exists in soil microbial communities, but these studies have not compared soils from geographically distant locations, nor have they utilized community ecology approaches, such as the core and satellite hypothesis and/or abundance-occupancy relationships, often used in macro-ecology, to improve the description of the spatial organization of communities. In the present work, we focused on bacterial diversity (i.e., 16S rRNA gene sequencing) occurring in micro-samples from a variety of locations with different pedo-climatic histories (i.e., from semi-arid, alpine, and temperate climates) and physicochemical properties. The forms of ecological spatial relationships in bacterial communities (i.e., occupancy-frequency and abundance-occupancy) and taxa distributions (i.e., habitat generalists and specialists) were investigated. The results showed that bacterial composition differed in the four soils at the small scale. Moreover, one soil presented a satellite mode distribution, whereas the three others presented bimodal distributions. Interestingly, numerous core taxa were present in the four soils among which 8 OTUs were common to the four sites. These results confirm that analyses of the small-scale spatial distribution are necessary to understand consequent functional processes taking place in soils, affecting thus ecosystem functioning.

微生物空间分布主要在田间到全球尺度（即生态系统尺度）进行研究。然而，小尺度（即厘米到毫米尺度）的空间组织有助于提高我们对空间群落结构对微生物功能影响的理解，但相对较少受到关注。先前的工作表明，土壤微生物群落中存在小尺度空间结构，但这些研究没有比较地理上遥远位置的土壤，也没有利用群落生态学方法，例如核心和卫星假设和/或丰度-占有率关系，常用于宏观生态学，以改进对社区空间组织的描述。在目前的工作中，我们专注于细菌多样性（即，16S rRNA 基因测序）发生在来自具有不同土壤气候历史（即来自半干旱、高山和温带气候）和物理化学特性的各种地点的微样本中。研究了细菌群落（即占有频率和丰度占有率）和分类群分布（即栖息地通才和专家）中生态空间关系的形式。结果表明，四种土壤中的细菌组成在小范围内存在差异。此外，一种土壤呈现卫星模式分布，而其他三种土壤呈现双峰分布。有趣的是，四个土壤中存在许多核心分类群，其中四个地点共有 8 个 OTU。