We investigated the monthly variations of estimated in‐situ uptake and growth‐related demand for phosphorus in Sargassum macrocarpum during a growth period from December 2017 to April 2018, a maturation period from May to August 2018, and the second‐growth period from September 2018 to January 2019. Phosphate uptake was relatively low during maturation and high during growth, and coincided with changes in external phosphate levels. The demand for phosphorus was at its highest in March 2018, which corresponded with the highest growth rate and tissue phosphorus levels. Thereafter, the demand was relatively constant between April 2018 and January 2019. Consequently, the uptake rate exceeded demand from December 2017 to February 2018 and December 2018 to January 2019, suggesting that phosphorus accumulated in tissues. Additionally, the uptake rates between March 2018 and November 2018 were 0.1–0.8 times lower than the demand, probably resulting in the effective use of stored phosphorus to sustain growth during this phosphate‐depleted period. The variations between estimated uptake and demands for P found in S. macrocarpum indicate that P dynamics vary with life stage and are implicitly linked to the season.

中文翻译：

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褐藻马尾藻生长和成熟过程中磷的需求和吸收

我们调查了在 2017 年 12 月至 2018 年 4 月的生长期、2018 年 5 月至 8 月的成熟期以及 2018 年 9 月的第二生长期期间，大果马尾藻中估计的原位吸收和与生长相关的磷需求的月变化到 2019 年 1 月。 成熟期间的磷酸盐吸收相对较低，生长期间的磷酸盐吸收较高，并且与外部磷酸盐水平的变化相吻合。对磷的需求在 2018 年 3 月达到最高，这与最高的增长率和组织磷水平相对应。此后，2018 年 4 月至 2019 年 1 月需求量相对稳定。因此，2017 年 12 月至 2018 年 2 月和 2018 年 12 月至 2019 年 1 月期间吸收率超过需求，表明磷在组织中积累。此外，2018 年 3 月至 2018 年 11 月之间的吸收率比需求低 0.1-0.8 倍，这可能导致有效利用储存的磷来维持磷耗竭期间的增长。在 S. macrocarpum 中发现的磷的估计吸收量和需求量之间的变化表明磷动态随生命阶段而变化，并且与季节有隐含的联系。