Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, 8057, Switzerland.
Department of Biological Sciences, Eck Institute of Global Health, Environmental Change Initiative, University of Notre Dame, Notre Dame, IN, USA.
Ecol Lett. 2020 Nov;23(11):1611-1622. doi: 10.1111/ele.13590. Epub 2020 Aug 18.
The dilution effect predicts increasing biodiversity to reduce the risk of infection, but the generality of this effect remains unresolved. Because biodiversity loss generates predictable changes in host community competence, we hypothesised that biodiversity loss might drive the dilution effect. We tested this hypothesis by reanalysing four previously published meta-analyses that came to contradictory conclusions regarding generality of the dilution effect. In the context of biodiversity loss, our analyses revealed a unifying pattern: dilution effects were inconsistently observed for natural biodiversity gradients, but were commonly observed for biodiversity gradients generated by disturbances causing losses of biodiversity. Incorporating biodiversity loss into tests of generality of the dilution effect further indicated that scale-dependency may strengthen the dilution effect only when biodiversity gradients are driven by biodiversity loss. Together, these results help to resolve one of the most contentious issues in disease ecology: the generality of the dilution effect.
稀释效应预测生物多样性的增加会降低感染的风险，但该效应的普遍性仍未得到解决。由于生物多样性的丧失会导致宿主群落能力产生可预测的变化，我们假设生物多样性的丧失可能会驱动稀释效应。我们通过重新分析四个先前发表的meta 分析来检验这一假设，这些分析对稀释效应的普遍性得出了相互矛盾的结论。在生物多样性丧失的背景下，我们的分析揭示了一个统一的模式：在自然生物多样性梯度中，稀释效应不一致地观察到，但在由导致生物多样性丧失的干扰引起的生物多样性梯度中通常观察到。将生物多样性丧失纳入稀释效应普遍性的检验进一步表明，只有当生物多样性梯度是由生物多样性丧失驱动时，尺度依赖性才可能增强稀释效应。总的来说，这些结果有助于解决疾病生态学中最具争议的问题之一：稀释效应的普遍性。
