Geonczy Sara E, Ter Horst Anneliek M, Emerson Joanne B
Department of Plant Pathology, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States.
ISME Commun. 2025 May 6;5(1):ycaf073. doi: 10.1093/ismeco/ycaf073. eCollection 2025 Jan.
Increased wildfire activity warrants more research into fire-driven biotic changes in soil, including soil viral communities, given the roles of soil microbes in organic matter decomposition, nutrient cycling, and post-fire recovery. Leveraging viral size-fraction metagenomes (viromes), here we studied viral community responses to wildfire in woodland and chaparral soils at five timepoints over 1 year following the California LNU Complex wildfire. We also compared post-fire samples to unburned controls at the final three timepoints and leveraged published viromes from the same sites nine months before the fire as pre-burn controls. Viral community composition differed significantly in burned samples compared to controls from both habitats, as did soil chemistry and prokaryotic communities (16S rRNA gene amplicons). Viromic DNA yields (a proxy for viral particle abundances) indicated initial viral biomass reductions due to the fire, but a return to baseline abundances (indistinguishable from controls) within five months. Fire-associated habitat filtering was further indicated by a comparison to the PIGEON viral "species" (viral operational taxonomic unit (vOTU)) reference database, with vOTUs from a burned conifer forest representing 19%-31% of PIGEON vOTUs detected in the burned habitats but only 0.6%-6% in controls. Together, these results indicate significant changes in soil viral communities due to wildfire, attributable at least in part to concomitant changes in their prokaryotic host communities and soil physicochemistry.
鉴于土壤微生物在有机质分解、养分循环和火灾后恢复中的作用，野火活动的增加促使人们对火灾驱动的土壤生物变化，包括土壤病毒群落，进行更多研究。利用病毒大小分级宏基因组（病毒组），我们研究了加利福尼亚州LNU复合大火后1年内五个时间点林地和丛林土壤中病毒群落对野火的反应。我们还在最后三个时间点将火灾后的样本与未燃烧的对照样本进行了比较，并利用火灾前九个月来自同一地点的已发表病毒组作为燃烧前的对照。与来自两个栖息地的对照相比，燃烧样本中的病毒群落组成有显著差异，土壤化学和原核生物群落（16S rRNA基因扩增子）也是如此。病毒组DNA产量（病毒颗粒丰度的一个指标）表明，火灾导致病毒生物量最初减少，但在五个月内恢复到基线丰度（与对照无差异）。与鸽子病毒“物种”（病毒操作分类单元（vOTU））参考数据库的比较进一步表明了与火灾相关的栖息地筛选，来自燃烧针叶林的vOTU占燃烧栖息地中检测到的鸽子vOTU的19%-31%，但在对照中仅占0.6%-6%。总之，这些结果表明野火导致土壤病毒群落发生显著变化，这至少部分归因于其原核宿主群落和土壤物理化学的伴随变化。
