Data from: Disentangling the ‘brown world’ faecal-detritus interaction web: dung beetle effects on soil microbial properties

Many ecosystem services are sustained by the combined action of microscopic and macroscopic organisms, and shaped by interactions between the two. However, studies tend to focus on only one of these two components. We combined the two by investigating the impact of macrofauna on microbial community composition and functioning in the context of a major ecosystem process: the decomposition of dung. We compared bacterial communities of pasture soil and experimental dung pats inhabited by one (Aphodius), two (Aphodius and Geotrupes), or no dung beetle genera. Overall, we found distinct microbial communities in soil and dung samples, and that the communities converged over the course of the experiment. Characterising the soil microbial communities underlying the dung pats revealed a significant interactive effect between the microflora and macrofauna, where the diversity and composition of microbial communities was significantly affected by the presence or absence of dung beetles. The specific identity of the beetles had no detectable impact, but the microbial evenness was lower in the presence of both Aphodius and Geotrupes than in the presence of Aphodius alone. Differences in microbial community composition were associated with differences in substrate usage as measured by Ecoplates. Moreover, microbial communities with similar compositions showed more similar substrate usage. Our study suggests that the presence of macrofauna (dung beetles) will modify the microflora (bacteria) of both dung pats and pasture soil, including community diversity and functioning. In particular, the presence of dung beetles promotes the transfer of bacteria across the soil-dung interface, resulting in increased similarity in community structure and functioning. The results demonstrate that to understand how microbes contribute to the ecosystem process of dung decomposition, there is a need to understand their interactions with larger co-occurring fauna.众多生态系统服务（ecosystem services）依赖微体生物与大型生物的协同作用得以维系，并通过二者间的相互作用塑造其过程与特征。然而现有研究往往仅聚焦于这两类生物组分中的一类。 本研究将二者结合，以粪便分解这一核心生态系统过程为研究背景，探究大型动物（macrofauna）对微生物群落组成与功能的影响。我们设置了三组实验处理：仅栖息1属蜣螂（Aphodius）、栖息2属蜣螂（Aphodius与Geotrupes）以及无蜣螂栖息的对照组，分别对牧场土壤与实验粪块（dung pats）中的细菌群落进行比较分析。 整体而言，土壤与粪块样本中的微生物群落结构存在显著差异，但在实验过程中两类群落的组成逐渐趋同。对粪块附着的土壤微生物群落进行表征分析后发现，微生物区系（microflora）与大型动物间存在显著的交互效应：蜣螂的有无会显著改变微生物群落的多样性与组成结构。不同蜣螂属的特异性作用未检测到显著影响，但同时存在Aphodius与Geotrupes两类蜣螂时，微生物群落的均匀度显著低于仅存在Aphodius的处理组。 微生物群落组成的差异与通过Ecoplates检测到的底物利用模式差异显著相关。此外，组成结构相似的微生物群落，其底物利用模式也更为相近。本研究表明，大型动物（此处特指蜣螂）的存在会改变粪块与牧场土壤中的微生物区系（细菌），包括群落多样性与功能。具体而言，蜣螂的存在可促进细菌在土壤-粪块界面间的转移，进而提升群落结构与功能的相似性。本研究结果证实，若要阐明微生物如何参与粪便分解的生态系统过程，需厘清其与共存大型动物间的相互作用。