Bond Charles T, Nave Brett A, Kemajou Tchamba Andrielle L, Stanley Emily, Zeglin Lydia H, Jackson Colin R, Zipper Sam, Aho Ken, Burgin Amy J, You Yaqi, Ramos Rob, Kuehn Kevin A
School of Biological, Environmental, and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406, United States.
Division of Biology, Kansas State University, Manhattan, KS 66506, United States.
ISME Commun. 2025 Aug 30;5(1):ycaf151. doi: 10.1093/ismeco/ycaf151. eCollection 2025 Jan.
Over half of the world's streams are non-perennial, drying at some point in space and time, but most research on stream-inhabiting fungi comes from perennial (continuously flowing) streams. To improve our understanding of fungal communities in non-perennial streams, we used ITS rDNA metabarcoding to survey fungal communities in three natural substrates (rock surfaces, decaying leaves, and sediments) across a surface water permanence gradient (determined via in-stream sensors) in a non-perennial prairie stream system in Kansas, USA. Fungal community composition varied along a continuum from wooded downstream reaches to increasingly open canopies (with grassy riparian vegetation) further upstream. Independently of position along this continuum, fungal community composition varied with annual surface water permanence. Communities on rock surfaces were the most sensitive to water impermanence, where rock-inhabiting freshwater lichens () were bioindicators of wetter () or drier () conditions. Position along the stream continuum explained more variation in fungal community composition than surface water permanence, possibly because of increasing network connectivity downstream or distinct fungal assemblages associated with grassy versus woody plants. Known drying-tolerant decomposers were among the dominant taxa (e.g. spp. and ). However, DNA-based studies of stream fungal communities remain challenging due to underrepresentation of aquatic hyphomycetes in reference databases and contributions of terrestrial fungi (some of which may be active in non-perennial streams) to measured diversity. As streamflow intermittency increases globally, this study provides unprecedented intra-watershed coverage of fungal communities and insights into how hydrology and riparian plants influence fungi across different benthic substrates.
世界上超过一半的溪流是非常年性的，会在空间和时间的某些点干涸，但大多数关于溪流真菌群落的研究都来自常年性（持续流动）溪流。为了更好地了解非常年性溪流中的真菌群落，我们使用内转录间隔区核糖体DNA（ITS rDNA）宏条形码技术，在美国堪萨斯州一个非常年性草原溪流系统中，沿着地表水持久性梯度（通过溪流内传感器确定），对三种天然基质（岩石表面、腐烂树叶和沉积物）中的真菌群落进行了调查。真菌群落组成沿着从下游树木繁茂的河段到上游树冠逐渐开阔（有草质河岸植被）的连续体而变化。独立于沿着这个连续体的位置，真菌群落组成随年度地表水持久性而变化。岩石表面的群落对水流无常最为敏感，栖息在岩石上的淡水地衣是更湿润或更干燥条件的生物指示物。沿着溪流连续体的位置比地表水持久性解释了真菌群落组成更多的变化，这可能是因为下游网络连通性增加，或者与草本植物和木本植物相关的真菌组合不同。已知的耐旱分解者是优势类群之一（例如 属和 属）。然而，由于参考数据库中水生丝状真菌的代表性不足以及陆地真菌（其中一些可能在非常年性溪流中活跃）对测量多样性的贡献，基于DNA的溪流真菌群落研究仍然具有挑战性。随着全球范围内河流流量间歇性的增加，这项研究提供了前所未有的流域内真菌群落覆盖范围，并深入了解了水文和河岸植物如何影响不同底栖基质上的真菌。
