Morphological traits variability reflects light limitation of phytoplankton production in a highly productive subtropical estuary (Río de la Plata, South America)
Morphological traits variability reflects light limitation of phytoplankton production in a highly productive subtropical estuary (Río de la Plata, South America)
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DOI：
10.1007/s00227-014-2568-6
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发表时间：
2015-02
期刊：
影响因子：
2.4
通讯作者：
C. Kruk;Ana Martínez;Lucía Nogueira;C. Alonso;D. Calliari
中科院分区：
文献类型：
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作者：
C. Kruk;Ana Martínez;Lucía Nogueira;C. Alonso;D. Calliari
基于特征的方法越来越多地用于了解浮游植物群落对环境条件变化的反应。本文分析了一个高生产力的亚热带河口（Ríode拉普拉塔，南美洲）的浮游植物形态特征（即体积，表面体积比）。我们的目标是调查是否形态变异，加权生物量，支持这一假设，即光是一个关键的限制因素，在这个浑浊和营养丰富的河口初级生产者。一个样带从近淡水到海洋站采样的混合深度增加，降低浊度和溶解无机氮浓度。初级生产力（PP）和总生物量是最高的海洋一侧的混浊锋。在这一地区，不同的高阶类群的形态收敛到更小的个体大小和更高的表面体积比（S/V）。浮游植物加权平均S/V随浊度沿着梯度增加，而个体大小与盐度。高S/V和低形态变异支持较高的PP，出现在这种环境中的光限制的应对措施。多元线性回归表明，形态变异单独解释72%的PP，加强了基于特征的方法的效用时，针对浮游植物群落和生态系统功能之间的关系。
Trait-based approaches are increasingly used to understand the responses of phytoplankton communities to changing environmental conditions. This paper analyses phytoplankton morphological traits (i.e. volume, surface to volume ratio) in a highly productive subtropical estuary (Río de la Plata, South America). The goal was to investigate whether morphological variability, weighted by biovolume, supports the hypothesis that light is a key limiting factor for primary producers in this turbid and nutrient-rich estuary. A transect from nearly freshwater to marine stations was sampled with increasing mixing depth, decreasing turbidity and dissolved inorganic nitrogen concentration. Primary production (PP) and total biovolume were highest on the marine side of the turbidity front. In this area, morphologies of different high-order taxa converged towards smaller individual size and higher surface to volume ratio (S/V). Phytoplankton weighted averageS/Vincreased with turbidity along the gradient, while individual size did so with salinity. HighS/Vand low morphological variability supported higher PP, appearing as responses to cope with light limitation in this environment. Multiple linear regressions indicated that morphological variability alone explained 72 % of PP, reinforcing the utility of trait-based approaches when targeting relations between phytoplankton communities and ecosystem functioning.