Abstract In aquatic ecosystems, young of the year (YOY) fish often exhibit strong interannual fluctuations. Because these fish prey on zooplankton and are preyed upon by piscivorous fish, strong fluctuations in their abundance may have important impacts on food web functioning. The static Ecopath model was used to assess potential impacts of strong fluctuations in YOY perch in the deep peri-alpine Lake Annecy. We modeled two contrasting years in terms of YOY perch biomass: a situation with a high biomass of YOY perch and a situation with a low biomass of YOY perch. Additionally, five models were derived from the two initial models to better explore the effects of YOY perch biomass fluctuations on food web functioning. Disparities were revealed in terms of the activity of the system (volume of flows) and the trophic transfer efficiency. When the YOY perch biomass was high, the volume of flows within the system was less important, but the trophic transfers were more efficient than when the biomass was low. The high biomass of YOY perch appeared to facilitate transfers from low to high trophic levels. The results indicated that strong variabilities in the abundance of YOY fish had little impact on the main food web flows and pathways because of the capacity of predators to feed on various prey (omnivory) but could induce significant differences in food web properties (e.g. ascendancy, robustness) and organization (e.g. cycling, mean trophic level).

中文翻译：

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湖泊食物网中的主要生物量波动——以高山安纳西湖为例

摘要 在水生生态系统中，年幼（YOY）鱼往往表现出强烈的年际波动。由于这些鱼捕食浮游动物并被食鱼鱼捕食，因此其丰度的强烈波动可能对食物网功能产生重要影响。静态生态路径模型用于评估深高山安纳西湖中 YOY 鲈鱼强烈波动的潜在影响。我们在 YOY 鲈鱼生物量方面模拟了两个截然不同的年份：YOY 鲈鱼生物量高的情况和 YOY 鲈鱼生物量低的情况。此外，从两个初始模型中衍生出五个模型，以更好地探索 YOY 鲈鱼生物量波动对食物网功能的影响。在系统活动（流量）和营养转移效率方面揭示了差异。当 YOY 鲈鱼生物量高时，系统内的流量不太重要，但营养转移比生物量低时更有效。YOY 鲈鱼的高生物量似乎促进了从低营养水平到高营养水平的转移。结果表明，由于捕食者以各种猎物（杂食性）为食的能力，YOY 鱼类丰度的强烈变化对主要食物网的流动和途径几乎没有影响，但可能会导致食物网特性的显着差异（例如优势、健壮性）和组织（例如骑自行车，平均营养水平）。YOY 鲈鱼的高生物量似乎促进了从低营养水平到高营养水平的转移。结果表明，由于捕食者以各种猎物（杂食性）为食的能力，YOY 鱼类丰度的强烈变化对主要食物网的流动和途径几乎没有影响，但可能会导致食物网特性的显着差异（例如优势、健壮性）和组织（例如骑自行车，平均营养水平）。YOY 鲈鱼的高生物量似乎促进了从低营养水平到高营养水平的转移。结果表明，由于捕食者以各种猎物（杂食性）为食的能力，YOY 鱼类丰度的强烈变化对主要食物网的流动和途径几乎没有影响，但可能会导致食物网特性的显着差异（例如优势、健壮性）和组织（例如骑自行车，平均营养水平）。