Abstract

In the last 50 years, traditionally nomadic indigenous communities in Amazonia have increasingly adopted more sedentary lifestyles as a result of external influences. Permanent settlements lead to the concentration of disturbances (e.g., forest extraction and hunting) and threaten vulnerable species as well as those that provide important ecosystem services such as dung beetles. Here we evaluated the abundance, taxonomic, and functional structure (composition and diversity) of an ecological indicator group—dung beetles—along a disturbance gradient associated with a permanent settlement of the Jotï people in the Amazonian region of Venezuela. We applied generalized linear model to assess the response of dung beetle abundance to settlement distance and latent variable model to assess the influence of settlement distance on taxonomic diversity and functional structure. We found the abundance of roller-species increased but small-bodied beetles decreased away from the settlement. We found that proximity to the Jotï settlement did not affect metrics of taxonomic and functional diversity of the dung beetle assemblages in general, although functional evenness was lower away from the settlement. In contrast, we found impacts on the functional composition of dung beetles, with significant increase in the community-weighted means for roller species and large-bodied dung beetles away from Jotï settlement. Our findings suggest that the transition from nomadism to a more sedentary lifestyle has not caused widespread collapse in the diversity of dung beetle assemblages surrounding the settlement, however significant trends were observed in species-specific responses to human impact, and these responses were mediated by functional traits.

中文翻译：

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土著居民点对委内瑞拉亚马逊河粪甲虫群落的分类和功能结构的影响

摘要

在过去的50年中，由于外部因素的影响，亚马逊地区的传统游牧土著社区越来越多地采用久坐的生活方式。永久定居导致干扰（例如森林采伐和狩猎）的集中，并威胁到脆弱的物种以及提供重要生态系统服务的物种，例如虫。在这里，我们评估了生态指示物群（甲虫）的丰度，分类学和功能结构（组成和多样性），以及与委内瑞拉亚马逊地区约提人永久定居有关的干扰梯度。我们应用广义线性模型评估粪便甲虫丰度对沉降距离的响应，并使用潜在变量模型评估沉降距离对分类学多样性和功能结构的影响。我们发现，远离定居点的轮虫种类丰富，但小型甲虫却减少了。我们发现，尽管功能均匀度比定居点低，但与Jotï定居点的接近程度一般不会影响粪甲虫组合的分类学和功能多样性。相比之下，我们发现了对粪便甲虫的功能成分的影响，远离Jotï定居点的轮虫和大体粪便甲虫的社区加权平均值显着增加。