ABSTRACT: An understanding of regulating factors and early warning of Ulva prolifera biomass increase may reduce harm or prevent bloom disasters in the Yellow Sea. We investigated the minimum nutrient concentration and light-limiting depth (Z_lim) for the growth of floating U. prolifera thalli. Bioavailable dissolved nitrogen (BDN) concentrations in most parts of the study area were almost always higher than the minimum N concentrations required for the growth of floating thalli, indicating no N limitation for the growth of floating thalli. However, the minimum N concentration required for the development of germlings into thalli was higher than BDN in the majority of the area north of 35°N. This indicated that germlings floating out of Subei Shoal were unable to grow into thalli because of N limitation. The minimum P concentration required for germling development was higher than the total dissolved P north of 35°N. This suggested that P limitation occurred for germlings floating out of Subei Shoal. The Z_lim for the floating thalli was <0.1 m in most parts of Subei Shoal, which explained why the rapid growth of floating thalli only occurred when they floated out from the Subei Shoal. A grid pattern with the phased multiple increase in biomass per day was designed to predict the possible accumulated multiple increase in biomass (AcMp) when U. prolifera drifted northward following different trajectories. The predicted AcMp values in 2017, 2010, and 2009 were close to the ratio of the coverage area from remote sensing data. Such a grid pattern facilitates quick decisions in disaster prevention and reduction.

中文翻译：

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南黄海石莼显着增加的机制：光强、氮、磷和共同限制的作用

摘要：了解黄海石莼生物量增加的调控因素和预警可以减少危害或预防黄海水华灾害。我们研究了漂浮U. prolifera生长的最小养分浓度和光限制深度（Z _lim）塔利。研究区大部分地区的生物可利用溶解氮 (BDN) 浓度几乎总是高于漂浮菌体生长所需的最低 N 浓度，表明漂浮菌体生长不受 N 限制。然而，在 35°N 以北的大部分地区，幼苗发育成菌体所需的最低 N 浓度高于 BDN。这说明苏北浅滩浮出的幼苗由于受氮限制而无法长成菌体。幼苗发育所需的最低磷浓度高于北纬 35°以北的总溶解磷。这表明浮出苏北浅滩的幼苗发生了磷限制。该ž _LIM苏北浅滩大部分地区的漂浮菌体<0.1 m，这就解释了为什么漂浮菌体只有从苏北浅滩浮出时才会快速增长。当U. prolifera按照不同的轨迹向北漂移时，每天生物量分阶段多次增加的网格模式旨在预测生物量可能累积的多次增加 (AcMp) 。2017年、2010年和2009年的AcMp预测值接近遥感数据覆盖面积的比值。这种网格模式有助于在防灾和减灾方面做出快速决策。