Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, 70402, USA.
Microb Ecol. 2020 Oct;80(3):603-613. doi: 10.1007/s00248-020-01522-9. Epub 2020 May 18.
Understanding the ecological processes that shape species assemblage patterns is central to community ecology. The effects of ecological processes on assemblage patterns are scale-dependent. We used metabarcoding and shotgun sequencing to determine bacterial taxonomic and functional assemblage patterns among varying defined focal scales (micro-, meso-, and macroscale) within the American alligator (Alligator mississippiensis) nesting microbiome. We correlate bacterial assemblage patterns among eight nesting compartments within and proximal to alligator nests (micro-), across 18 nests (meso-), and between 4 geographic sampling sites (macro-), to determine which ecological processes may drive bacterial assemblage patterns within the nesting environment. Among all focal scales, bacterial taxonomic and functional richness (α-diversity) did not statistically differ. In contrast, bacterial assemblage structure (β-diversity) was unique across all focal scales, whereas functional pathways were redundant within nests and across geographic sites. Considering these observed scale-based patterns, taxonomic bacterial composition may be governed by unique environmental filters and dispersal limitations relative to microbial functional attributes within the alligator nesting environment. These results advance pattern-process dynamics within the field of microbial community ecology and describe processes influencing the American alligator nest microbiome.
理解塑造物种组合模式的生态过程是群落生态学的核心。生态过程对组合模式的影响是尺度依赖的。我们使用代谢组学和鸟枪法测序来确定美洲鳄（Alligator mississippiensis）筑巢微生物组中不同定义焦点尺度（微观、中观和宏观）内的细菌分类和功能组合模式。我们在鳄鱼巢内和周围的 8 个巢内隔室（微观）、18 个巢（中观）和 4 个地理采样点（宏观）之间相互关联细菌组合模式，以确定哪些生态过程可能在筑巢环境中驱动细菌组合模式。在所有焦点尺度中，细菌分类和功能丰富度（α-多样性）没有统计学差异。相比之下，细菌组合结构（β-多样性）在所有焦点尺度上都是独特的，而功能途径在巢内和地理地点之间是冗余的。考虑到这些观察到的基于尺度的模式，相对于美洲鳄筑巢环境中的微生物功能属性，细菌分类组成可能受到独特的环境过滤器和扩散限制的影响。这些结果推进了微生物群落生态学领域内的模式-过程动态，并描述了影响美洲鳄巢微生物组的过程。
