Abstract Evidence is accumulating to show that changes in host diversity can affect disease risk, yet the relationship between them is still disputed. Understanding what factors influence this relationship will help to reconcile this debate. In this paper, through spatially-explicit simulations, we investigated the effects of host spatial distribution patterns, the scale of host interactions (i.e. local vs. global interactions), the presence or absence of life history trade-offs, and community assembly rules on the diversity–disease relationship when the pathogen was a generalist. The results showed that intraspecific aggregation enhanced disease risk, while increased global interactions between hosts reduced disease risk. For a given host species richness level, the effect of the scale of host interactions on disease risk increased with intraspecific aggregation. However, neither species distribution patterns nor the scale of host interactions could reverse the diversity-disease relationship. The direction and strength of diversity on disease risk depended on community assembly and life history trade-offs. These results suggest that species distribution patterns and the scale of host interactions do not contribute to the discrepancy in results that lead to the debate over dilution effect, highlighting the complexity of mechanisms underlying the diversity–disease relationship.

中文翻译：

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物种分布模式和宿主相互作用的规模定量但不定性影响多样性 - 疾病关系

摘要 越来越多的证据表明宿主多样性的变化会影响疾病风险，但它们之间的关系仍然存在争议。了解影响这种关系的因素将有助于调和这场辩论。在本文中，通过空间显式模拟，我们研究了宿主空间分布模式、宿主相互作用的规模（即局部与全局相互作用）、生活史权衡的存在与否以及社区组装规则的影响。当病原体是通才时的多样性-疾病关系。结果表明，种内聚集增加了疾病风险，而宿主之间增加的全球相互作用降低了疾病风险。对于给定的寄主物种丰富度水平，宿主相互作用的规模对疾病风险的影响随着种内聚集而增加。然而，物种分布模式和宿主相互作用的规模都不能逆转多样性与疾病的关系。疾病风险多样性的方向和强度取决于社区集会和生活史权衡。这些结果表明，物种分布模式和宿主相互作用的规模不会导致导致稀释效应争论的结果差异，突出了多样性-疾病关系背后机制的复杂性。疾病风险多样性的方向和强度取决于社区集会和生活史权衡。这些结果表明，物种分布模式和宿主相互作用的规模不会导致导致稀释效应争论的结果差异，突出了多样性-疾病关系背后机制的复杂性。疾病风险多样性的方向和强度取决于社区集会和生活史权衡。这些结果表明，物种分布模式和宿主相互作用的规模不会导致导致稀释效应争论的结果差异，突出了多样性-疾病关系背后机制的复杂性。