A schematic illustration of the experimental design.

Rodents were trapped in 1-ha plots (squares), representing populations of Gerbillus andersoni [(A), host individuals are represented as green rodent outlines and the populations are shaded pink], G. pyramidum [(B), purple outlines and green shading] and G. gerbillus [(C), red outlines and blue shading]. The rodent populations were part of three communities; a single host species (G. andersoni, left tan shading), two (G. andersoni and G. pyramidum, middle tan shading) or three rodent species communities (right tan shading). Bacterial lineage (rod-like shapes) diversity and composition were assessed for three organization levels (individuals, populations and communities of hosts) nested within three hierarchical spatial scales (a host individual, a plot, and a region).

研究人员于1公顷正方形样地中诱捕沙鼠，该样地分别对应三类沙鼠的种群：安德森沙鼠（Gerbillus andersoni）[图A：宿主个体以绿色沙鼠轮廓标示，种群区域以粉色填充]、金字塔沙鼠（G. pyramidum）[图B：宿主个体以紫色沙鼠轮廓标示，种群区域以绿色填充]以及肥沙鼠（G. gerbillus）[图C：宿主个体以红色沙鼠轮廓标示，种群区域以蓝色填充]。上述沙鼠种群隶属于三类群落：单宿主物种群落（仅包含安德森沙鼠，左侧浅棕色填充）、双宿主物种群落（包含安德森沙鼠与金字塔沙鼠，中间浅棕色填充）以及三宿主物种群落（涵盖全部三种沙鼠，右侧浅棕色填充）。本研究针对宿主个体、种群与宿主群落三类组织层级，在三级嵌套的空间尺度（宿主个体、样地与区域）下，对棒状形态的细菌类群（Bacterial lineage）的多样性与组成进行了评估分析。