Classical ecological theory posits that species partition resources such that each species occupies a unique resource niche. In general, the availability of more resources allows more species to co-occur. Thus, a strong relationship between communities of consumers and their resources is expected. However, correlations may be influenced by other layers in the food web, or by the environment. Here we show, by studying the relationship between communities of consumers (land snails) and individual diets (from seed plants), that there is in fact no direct, or at most a weak but negative, relationship. However, we found that the diversity of the individual microbiome positively correlates with both consumer community diversity and individual diet diversity in three target species. Moreover, these correlations were affected by various environmental variables, such as anthropogenic activity, habitat island size, and a possibly important nutrient source, guano runoff from nearby caves. Our results suggest that the microbiome and the environment explain the absence of correlations between diet and consumer community diversity. Hence, we advocate that microbiome inventories are routinely added to any community dietary analysis, which our study shows can be done with relatively little extra effort. Our approach presents the tools to quickly obtain an overview of the relationships between consumers and their resources. We anticipate our approach to be useful for ecologists and environmentalist studying different communities in a local food web.

中文翻译：

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微生物组和环境解释了婆罗洲小蜗牛消费者与其饮食之间缺乏相关性


经典生态理论认为，物种分配资源，使每个物种占据独特的资源生态位。一般来说，更多资源的可用性允许更多物种共存。因此，消费者社区与其资源之间有望建立牢固的关系。然而，相关性可能会受到食物网中其他层或环境的影响。在这里，我们通过研究消费者群体（陆地蜗牛）和个体饮食（来自种子植物）之间的关系表明，实际上不存在直接关系，或者至多是微弱但消极的关系。然而，我们发现三个目标物种中个体微生物组的多样性与消费者群体多样性和个体饮食多样性呈正相关。此外，这些相关性还受到各种环境变量的影响，例如人类活动、栖息地岛屿大小以及可能重要的营养源，即附近洞穴的鸟粪径流。我们的结果表明，微生物组和环境解释了饮食和消费者群体多样性之间缺乏相关性。因此，我们主张将微生物组清单常规添加到任何社区饮食分析中，我们的研究表明，只需相对较少的额外努力即可完成这一工作。我们的方法提供了快速了解消费者及其资源之间关系的工具。我们预计我们的方法对于生态学家和环保主义者研究当地食物网中的不同社区很有用。