Disturbance shapes the structure and function of aquatic communities and ecosystems, but the dynamics of ice are a less studied dimension of the disturbance‐regime of rivers. We investigated effects of a river‐ice regime on organic‐matter dynamics and feeding ecology of aquatic insects. Samples of biofilm and aquatic insects for gut content analysis were collected monthly from Big Creek, a sixth ‐ order tributary of the Middle Fork Salmon River in central Idaho, USA, during winter 2010–2011. Our results indicate that river ice affects both quantity and quality of organic matter available to, and used by, consumers. Specifically, scour from December and February ice break‐up events reduced biofilm biomass by one‐half and one‐third, respectively, whereas quality (chlorophyll‐a: ash‐free dry mass) increased. Diets of scrapers, Rhithrogena (Heptageniidae) and Bibiocephala (Blephariceridae), collector‐gatherers, Baetis (Baetidae), and collector‐filterers, Simulium (Simulidae) appeared to follow patterns of organic matter. Following ice break‐up events, diets of these taxa had increased proportions of diatom frustules, which are high‐quality food resources due to their relatively high nutrient content. Other taxa, such as collector‐gatherers, non‐Tanypodinae (Chironomidae), and the collector‐filterer, Arctopsyche grandis (Hydropsychidae), consistently consumed high proportions of diatom frustules and insect material, respectively, suggesting they were able to feed more selectively throughout winter. Our study indicates that ice regimes in temperate rivers can affect organic‐matter dynamics and feeding ecology of aquatic insects, a possibility that deserves additional investigation, particularly in light of potential changes to the ice regimes of rivers with changing climate.

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河冰破碎对水生昆虫有机物动力学和摄食生态的影响

扰动影响着水生群落和生态系统的结构和功能，但冰的动力学是河流扰动范围研究较少的方面。我们研究了河冰制度对水生昆虫有机物动力学和摄食生态的影响。在2010-2011年冬季，每月从美国爱达荷州中部中叉鲑鱼河的六级支流Big Creek采集用于肠含量分析的生物膜和水生昆虫样品。我们的结果表明，河冰影响到消费者可用和使用的有机物的数量和质量。具体而言，12月和2月的冰崩事件冲刷使生物膜生物量分别减少了一半和三分之一，而质量（叶绿素a：无灰干重）增加。刮削器的饮食，Rhithrogena（Heptageniidae）和Bibiocephala（Blephariceridae） ，集电极-采集，Baetis（Baetidae），和集电极- filterers，蚋（蚋）似乎遵循的有机物图案。破冰事件发生后，这些类群的饮食中硅藻壳的比例增加，硅藻壳由于其相对较高的营养成分而成为优质食品资源。其他分类单元，例如采集器和采集器（Arcopsyche grandis），非捕蝇科（Chironomidae）和采集过滤器（Arctopsyche grandis）（Hydropsychidae）分别持续消耗高比例的硅藻壳和昆虫材料，这表明它们在整个冬季能够选择性地进食。我们的研究表明，温带河流的冰层会影响有机物的动态变化和水生昆虫的摄食生态，这一可能性值得进一步研究，尤其是考虑到气候变化导致河流冰层的潜在变化。