Harvest plays an important role in management decisions, from fisheries to pest control. Discrete-time models enable us to explore the importance of timing of management decisions, including the order of events of particular actions. We derive novel mechanistic models featuring explicit within-season harvest timing and level. We explore optimization of within-season harvest level and timing through optimal control of these population models. With a fixed harvest level, harvest timing is taken as the control. Then both harvest timing and level are used as controls. We maximize an objective functional which includes management goals of maximizing yield, maximizing stock, and minimizing costs associated with both harvest intensity and harvest timing. While standard models with compensatory population dynamics predict it is best to harvest as early as possible in the season, we find instances where harvesting later in the season is optimal. Furthermore, we discover interesting oscillations in the population size, which would be unexpected in the model without time-varying controls.

中文翻译：

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离散种群模型中收获时间的最优控制

收获在管理决策中发挥着重要作用，从渔业到害虫控制。离散时间模型使我们能够探索管理决策时间的重要性，包括特定行动的事件顺序。我们推导出新颖的机械模型，具有明确的季节内收获时间和水平。我们通过对这些种群模型的最佳控制来探索季节内收获水平和时间的优化。在固定的收获水平下，以收获时间为控制。然后收获时间和水平都用作控制。我们最大化目标函数，其中包括最大化产量、最大化库存以及最小化与收获强度和收获时间相关的成本的管理目标。虽然具有补偿性种群动态的标准模型预测最好在本季节尽早收获，但我们发现在本季节晚些时候收获是最佳的实例。此外，我们发现了人口规模的有趣振荡，这在没有时变控制的模型中是出乎意料的。