Phytoplankton growth can cause red tide, lowering water quality and damaging fisheries. The simple Lotka–Volterra model (LV model), estimating the population changes in different species, is often used to analyze the growth and competition of causative species. However, the LV model has not been sufficiently applied to examining the actual occurrence and development of red tides in the field. Therefore, the mechanism of seasonal dominant species replacement and applicability of the LV model were studied to analyze the competition between the harmful raphidophytes and . Sensitivity analysis was performed, and optimization method of competition coefficient (α) was discussed by comparison with measured data from culture experiments. We found that it is crucial to evaluate in advance the initial cell density conditions under which the population size changes concerning α (the order of root mean squared logarithmic error ≥ 10). Using this as a reference, we pointed that the initial cell density difference between the two species in co-culture experiments should be as large as possible. In addition, simulation analysis using the model revealed that growth rate () and carrying capacity () determine dominance in spring, and the increase in α due to rising temperatures causes dominance in summer. Comparing α of with α of cited from a previous study found that the formation of red tides of less than that of can be explained by α that is 0.42 times smaller than α of . Moreover, the increase in α with increasing temperature is related to the physiological and ecological characteristics of , which is more likely to dominate the space suitable for growth with temperature rise. We consider that investigations of α, in particular, contributes to modeling various competition and more improving accuracy in analyses. These results provide valuable scientific findings on the occurrence and development of red tide flagellates and their analytical method.

中文翻译：

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使用 Lotka-Volterra 模型阐明有害针叶植物 Chattonella marina 和 Heterosigma akashiwo 的季节性优势更替机制

浮游植物的生长会引起赤潮，降低水质并损害渔业。简单的 Lotka-Volterra 模型（LV 模型）估计不同物种的种群变化，通常用于分析致病物种的生长和竞争。然而，LV模型尚未充分应用于实地考察赤潮的实际发生和发展。因此，对季节性优势种更替机制和LV模型的适用性进行了研究，以分析有害针叶植物与.进行敏感性分析，并通过与培养实验实测数据的比较，探讨竞争系数（α）的优化方法。我们发现，提前评估细胞群大小随α（均方根对数误差≥10的阶次）变化的初始细胞密度条件至关重要。以此为参考，我们指出共培养实验中两个物种之间的初始细胞密度差异应尽可能大。此外，使用该模型进行的模拟分析表明，生长率（）和承载力（）决定了春季的主导地位，而由于气温升高而导致的α增加导致了夏季的主导地位。将 α 与先前研究中引用的 α 进行比较发现，小于 的赤潮的形成可以用 α 比 α 小 0.42 倍来解释。而且，α随温度升高而增大，与 的生理生态特性有关，随着温度升高，更容易主导适合生长的空间。我们认为，对 α 的研究尤其有助于对各种竞争进行建模，并进一步提高分析的准确性。这些结果为赤潮鞭毛虫的发生、发展及其分析方法提供了有价值的科学发现。