Diverging effects of host density and richness across biological scales drive diversity-disease outcomes
Diverging effects of host density and richness across biological scales drive diversity-disease outcomes
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DOI：
10.1038/s41467-024-46091-4
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发表时间：
2024-03-02
影响因子：
16.6
通讯作者：
Fenton，Andy
中科院分区：
文献类型：
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作者：
Johnson，Pieter T. J.;Merrill，Tara E. Stewart;Fenton，Andy
了解生物多样性如何影响病原体传播仍然是一个未解决的问题，因为在测试自然系统中的潜在机制以及这些机制在生物尺度上如何变化面临挑战。通过对902个两栖动物宿主群落中整个寄生虫（幼虫虫）的传播进行量化，我们表明，群落水平的感染驱动因素主要取决于生物规模。在个体寄主尺度上，寄主丰富度的增加导致所有寄主分类群的寄主数量减少，不受寄主或捕食者密度的影响。然而，在寄主群落尺度上，丰富度的抑制作用被寄主总密度的增加所抵消，导致寄主密度总体上没有变化。在机制上，我们发现寄主的平均能力随着寄主丰富度的增加而下降，但由于加性组装模式，群落的总能力保持稳定。这些结果通过从经验上解开寄生虫传播的其他生态驱动因素的作用，以及这些影响如何取决于生物规模，有助于调和疾病多样性的争论。
Understanding how biodiversity affects pathogen transmission remains an unresolved question due to the challenges in testing potential mechanisms in natural systems and how these mechanisms vary across biological scales. By quantifying transmission of an entire guild of parasites (larval trematodes) within 902 amphibian host communities, we show that the community-level drivers of infection depend critically on biological scale. At the individual host scale, increases in host richness led to fewer parasites per host for all parasite taxa, with no effect of host or predator densities. At the host community scale, however, the inhibitory effects of richness were counteracted by associated increases in total host density, leading to no overall change in parasite densities. Mechanistically, we find that while average host competence declined with increasing host richness, total community competence remained stable due to additive assembly patterns. These results help reconcile disease-diversity debates by empirically disentangling the roles of alternative ecological drivers of parasite transmission and how such effects depend on biological scale.