Nutrient regulation of phytoplankton productivity in Monterey Bay, California
Nutrient regulation of phytoplankton productivity in Monterey Bay, California
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DOI：
10.1016/s0967-0645(99)00135-6
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发表时间：
2000-01-01
影响因子：
3
通讯作者：
Dugdale, RC
中科院分区：
文献类型：
--
作者：
Kudela, RM;Dugdale, RC
在加州的蒙特雷湾进行了一系列营养强化生长实验。为了评估营养物可利用性对自然浮游植物组合的生长速率和生物量积累的相对重要性，在一系列的四次巡航中，用氮（如硝酸盐和铵）、硅酸盐和Guillard的“f”培养基富集一致地表明浮游植物是氮限制的，并且硝酸盐的添加提供了最大的生长和生物量积累潜力。相反，以前的报告蒙特雷湾，硅酸盐没有发现限制生物量的积累，在这个以水为主的系统，虽然有证据表明，硅酸盐添加可以修改的生物量限制性基质（氮）的吸收率。我们的结论是，硅酸盐是一种调节，但不是限制，在这个研究地点的营养。在上升流期间（5月、9月），当生物量主要为浮游植物时，观察到了一种不依赖于吸收标准化过程的上移型生理反应（例如，在浮游植物的吸收标准化过程中，吸收标准化过程是一个重要的过程）。在冬季（3月，11月），其特征是深混合，低光，和较高的碎屑N水平，明显的上移响应可归因于PN：叶绿素比的变化和减轻光限制，由于由外壳提供的稳定的光制度。(C)2000爱思唯尔科技有限公司版权所有。
A series of nutrient enrichment grow-out experiments were conducted in Monterey Bay, California. to assess the relative importance of nutrient availability on growth rates and biomass accumulation of the natural phytoplankton assemblage, During a series of four cruises, enrichments with nitrogen (as nitrate and ammonium), silicate, and Guillard's "f" medium consistently demonstrated that the phytoplankton were nitrogen limited, and that the addition of nitrate provided the most potential for growth and biomass accumulation. Contrary to previous reports for Monterey Bay, silicate was not found to limit the accumulation of biomass in this diatom-dominated system, although there was evidence that silicate additions can modify the uptake rates of the biomass-limiting substrate (nitrogen). We conclude that silicate is a regulating, but not limiting, nutrient in this study site. Our results are consistent with both the "shift-up" and "detrital" explanations for changes in specific uptake rates, During upwelling periods (May, September) when the biomass was dominated by phytoplankton, a shift-up type physiological response was observed that was not dependent on the uptake normalization procedure (e,g. chlorophyll versus PN), During the winter months (March, November), characterized by deep mixing, low light, and higher detrital N levels, the apparent shift-up response could be attributed to a change in the PN:Chl ratios and alleviation of light limitation due to the stable light regime provided by the enclosures. (C) 2000 Elsevier Science Ltd. All rights reserved.