Sequential nutrient uptake as a potential mechanism for phytoplankton to maintain high primary productivity and balanced nutrient stoichiometry
Sequential nutrient uptake as a potential mechanism for phytoplankton to maintain high primary productivity and balanced nutrient stoichiometry
复制标题
连续养分吸收是浮游植物保持高初级生产力和平衡养分化学计量的潜在机制
DOI：
10.5194/bg-14-2469-2017
复制
发表时间：
2017-05
期刊：
影响因子：
4.9
通讯作者：
Harrison Paul J.
中科院分区：
文献类型：
--
作者：
Yin Kedong;Liu Hao;Harrison Paul J.
抽象的。我们假设浮游植物具有连续的营养吸收策略，以维持水体中的营养物质化学计量和高初级生产力。根据这一假设，浮游植物首先吸收最有限的营养物质，直到耗尽，然后继续消耗非限制营养物质，然后在可用时迅速吸收最有限的营养物质。这些过程将导致水体中环境营养物比率在雷德菲尔德比率附近的变化。我们在佐治亚州海峡使用了高分辨率的连续营养物垂直剖面、营养物比例和船上孵化实验来验证这一假设。夏季表层，周围的NO3−被耗尽，剩余的PO43−和SiO4−，导致N ： P和N ： Si比值都很低。这两个比率分别增加到约10 ： 1和0。 45 ： 1，在20 m。垂直剖面的时间序列显示，剩余的PO43−继续被去除，导致浮游植物对磷的额外储存。垂直剖面中线的N- ： -P比值对混合事件的响应不同。海水样品的野外培养也表明，NO3-−是最具限制性的营养物质，其次是PO43-−和SiO4-−(非限制性营养物质)。这种顺序吸收策略允许浮游植物在可用时获得额外的细胞磷和硅，并等待氮通过N3NH4(或脉冲再生−)的频繁混合而变得可用。因此，浮游植物能够保持高生产力和平衡营养物质化学计量比，利用强有力的混合制度和化学计量可塑性的能力。据我们所知，这是首次显示连续垂直剖面N- ： -P和N- ： -Si比值的原位动态，为深入了解水体中营养物质化学计量学的原位动态和推断近岸海洋浮游植物营养物质化学计量学的瞬时状态提供了依据。
Abstract. We hypothesize that phytoplankton have the sequential nutrient uptake strategy to maintain nutrient stoichiometry and high primary productivity in the water column. According to this hypothesis, phytoplankton take up the most limiting nutrient first until depletion, continue to draw down non-limiting nutrients and then take up the most limiting nutrient rapidly when it is available. These processes would result in the variation of ambient nutrient ratios in the water column around the Redfield ratio. We used high-resolution continuous vertical profiles of nutrients, nutrient ratios and on-board ship incubation experiments to test this hypothesis in the Strait of Georgia. At the surface in summer, ambient NO3− was depleted with excess PO43− and SiO4− remaining, and as a result, both N : P and N : Si ratios were low. The two ratios increased to about 10 : 1 and 0. 45 : 1, respectively, at 20 m. Time series of vertical profiles showed that the leftover PO43− continued to be removed, resulting in additional phosphorus storage by phytoplankton. The N : P ratios at the nutricline in vertical profiles responded differently to mixing events. Field incubation of seawater samples also demonstrated the sequential uptake of NO3− (the most limiting nutrient) and then PO43− and SiO4− (the non-limiting nutrients). This sequential uptake strategy allows phytoplankton to acquire additional cellular phosphorus and silicon when they are available and wait for nitrogen to become available through frequent mixing of NO3− (or pulsed regenerated NH4). Thus, phytoplankton are able to maintain high productivity and balance nutrient stoichiometry by taking advantage of vigorous mixing regimes with the capacity of the stoichiometric plasticity. To our knowledge, this is the first study to show the in situ dynamics of continuous vertical profiles of N : P and N : Si ratios, which can provide insight into the in situ dynamics of nutrient stoichiometry in the water column and the inference of the transient status of phytoplankton nutrient stoichiometry in the coastal ocean.
登录
查看更多内容
影响因子：
4.9
作者：
Ashutosh Kumar Singh;S. Baer;U. Riebesell;A. Martiny;M. Lomas
通讯作者：
Ashutosh Kumar Singh;S. Baer;U. Riebesell;A. Martiny;M. Lomas
影响因子：
56.9
作者：
J. McCarthy;J. C. Goldman
通讯作者：
J. McCarthy;J. C. Goldman
影响因子：
2.1
作者：
A. C. Redfield
通讯作者：
A. C. Redfield
影响因子：
4.5
作者：
N. M. Price
通讯作者：
N. M. Price
影响因子：
2.4
作者：
H. L. Conway;H. L. Conway;P. Harrison;C. Davis
通讯作者：
H. L. Conway;H. L. Conway;P. Harrison;C. Davis