Contribution of zooplankton nutrient recycling and effects on phytoplankton size structure in a hypereutrophic reservoir
Contribution of zooplankton nutrient recycling and effects on phytoplankton size structure in a hypereutrophic reservoir
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DOI：
10.1093/plankt/fbac045
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发表时间：
2022-09-12
影响因子：
2.1
通讯作者：
Wilkinson, Grace M.
中科院分区：
文献类型：
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作者：
Butts, Tyler J.;Moody, Eric K.;Wilkinson, Grace M.
消费者营养循环通过改变营养物质的运动和转化来影响水生态系统的功能。在富营养化水库，浮游动物营养再循环已被认为是微不足道的，由于高浓度的有效营养。一项比较分析（）发现，富营养化湖泊中的浮游动物群落以富氮（N）物种为主，作者假设这将通过排泄增加磷（P）的可用性。然而，浮游动物的营养循环可能会有所不同，在整个生长季节，由于生物量的变化，群落组成和放牧浮游植物的压力。我们量化了2019年夏季在温带超富营养化水库中的浮游动物，浮游植物和营养物浓度动态。我们发现，在一个给定的一天，浮游动物排泄的溶解营养池的估计贡献相当于一个很大的比例（21-39%）的溶解无机P常备股票在初夏时，P浓度低，限制浮游植物的生长。此外，我们发现的证据表明，浮游动物影响浮游植物的大小分布，通过选择性放牧较小的浮游植物细胞可能会影响浮游植物的营养吸收和储存。总体而言，我们的研究结果表明，浮游动物排泄在超营养水库可能有助于推动春季浮游植物的营养循环，而放牧影响浮游植物的大小分布的动态。
Consumer nutrient recycling influences aquatic ecosystem functioning by altering the movement and transformation of nutrients. In hypereutrophic reservoirs, zooplankton nutrient recycling has been considered negligible due to high concentrations of available nutrients. A comparative analysis ( ) found that zooplankton communities in hypereutrophic lakes are dominated by nitrogen (N)-rich species, which the authors hypothesized would increase phosphorus (P) availability through excretion. However, zooplankton nutrient recycling likely varies over the course of a growing season due to changes in biomass, community composition and grazing pressure on phytoplankton. We quantified zooplankton, phytoplankton and nutrient concentration dynamics during the summer of 2019 in a temperate, hypereutrophic reservoir. We found that the estimated contribution of zooplankton excretion to the dissolved nutrient pool on a given day was equivalent to a substantial proportion (21-39%) of the dissolved inorganic P standing stock in early summer when P concentrations were low and limiting phytoplankton growth. Further, we found evidence that zooplankton affected phytoplankton size distributions through selective grazing of smaller phytoplankton cells likely affecting nutrient uptake and storage by phytoplankton. Overall, our results demonstrate zooplankton excretion in hypereutrophic reservoirs likely helped drive springtime phytoplankton dynamics through nutrient recycling while grazing influenced phytoplankton size distributions.