Seasonal variability in planktonic food web structure and function of the Northeast U.S. Shelf
Seasonal variability in planktonic food web structure and function of the Northeast U.S. Shelf
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DOI：
10.1002/lno.11696
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发表时间：
2021-01
影响因子：
4.5
通讯作者：
P. Marrec;Heather Mcnair;Gayantonia Franzè;F. Morison;J. Strock;S. Menden‐Deuer
中科院分区：
文献类型：
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作者：
P. Marrec;Heather Mcnair;Gayantonia Franzè;F. Morison;J. Strock;S. Menden‐Deuer
初级产品的草食消费是全球生物地球化学循环中的一个关键转变，将物质和能量引导到更高的营养水平、出口生产或再矿化。微型浮游动物的放牧往往受到很差的限制，特别是在动态的沿海系统。温带沿海地区在季节和空间上是可变的，这给确定放牧压力的模式和驱动因素带来了挑战和机会。在这里，我们报道了为期一周的两次冬季和一次夏季巡航(2018-2019年)，这是新的美国东北大陆架长期生态研究计划的一部分。在这两个季节，沿海水域比陆架断裂时的水域更冷、更新鲜，浮游植物生物量更高。浮游植物群落冬季以大细胞为主，夏季以小细胞为主。浮游植物的生长率(%PP<；20%)低于夏季(%PP<；20%)，突出了浮游食物网结构和功能的季节性变化。这些结果表明，环境条件的可预测变化可以与生态系统净初级生产力的变化联系在一起。可变性的等级，从局部到年际和长期气候驱动，可以在持续测量生态系统属性和功能的背景下理解。
Herbivorous consumption of primary production is a key transformation in global biogeochemical cycles, directing matter and energy either to higher trophic levels, export production, or remineralization. Grazing by microzooplankton is often poorly constrained, particularly in dynamic coastal systems. Temperate coastal areas are seasonally and spatially variable, which presents both challenges and opportunities to identify patterns and drivers of grazing pressure. Here we report on two winter and one summer week‐long cruises (2018–2019), as part of the new Northeast U.S. Shelf Long‐Term Ecological Research program. During both seasons, coastal waters were colder and fresher, and had higher phytoplankton biomass than waters at the shelf break. The phytoplankton community was dominated by large cells in winter and by small cells in summer. Phytoplankton growth rates ranged from 50%) than during summer (%PP < 20%), highlighting seasonal shifts in planktonic food web structure and function. These results imply that predictable shifts in environmental conditions can be linked to ecosystem shifts in net primary production. Hierarchies of variability, from localized to interannual and long‐term climate driven, can be understood within the context of sustained measurements of ecosystem properties and function.