Abstract Natural ecosystems provide humans with different types of ecosystem services, often linked to biodiversity. The dilution effect (DE) predicts a negative relationship between biodiversity and risk of infectious diseases of humans, other animals, and plants. We hypothesized that a stronger DE would be observed in studies conducted at smaller spatial scales, where biotic drivers may predominate, compared to studies at larger spatial scales where abiotic drivers may more strongly affect disease patterns. In addition, we hypothesized a stronger DE in studies from temperate regions at mid latitudes than in those from subtropical and tropical regions, due to more diffuse species interactions at low latitudes. To explore these hypotheses, we conducted a meta‐analysis of observational studies of diversity–disease relationships for animals across spatial scales and geographic regions. Negative diversity–disease relationships were significant at small (combined site and local), intermediate (combined landscape and regional), and large (combined continental and global) scales and the effect did not differ depending on size of the study areas. For the geographic region analysis, a strongly negative diversity–disease relationship was found in the temperate region while no effect was found in the subtropical and tropical regions. However, no overall effect of absolute latitude on the strength of the dilution effect was detected. Our results suggest that a negative diversity–disease relationship occurs across scales and latitudes and is especially strong in the temperate region. These findings may help guide future management efforts in lowering disease risk.

中文翻译：

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空间尺度和纬度对多样性-疾病关系的影响

摘要 自然生态系统为人类提供不同类型的生态系统服务，通常与生物多样性有关。稀释效应 (DE) 预测生物多样性与人类、其他动物和植物的传染病风险之间存在负相关关系。我们假设，与在更大空间尺度上进行的研究相比，在较小空间尺度上进行的研究会观察到更强的 DE，其中生物驱动因素可能占主导地位，而在更大空间尺度上进行的研究可能更强烈地影响疾病模式。此外，我们假设中纬度温带地区的研究比亚热带和热带地区的研究更强，因为低纬度地区的物种相互作用更分散。为了探索这些假设，我们对跨空间尺度和地理区域的动物多样性-疾病关系的观察性研究进行了荟萃分析。负的多样性-疾病关系在小（结合地点和地方）、中间（结合景观和区域）和大（结合大陆和全球）尺度上是显着的，并且影响没有因研究区域的大小而异。对于地理区域分析，在温带地区发现了强烈的负多样性-疾病关系，而在亚热带和热带地区没有发现影响。然而，没有检测到绝对纬度对稀释效应强度的总体影响。我们的研究结果表明，负的多样性-疾病关系发生在跨尺度和纬度，在温带地区尤其强烈。