标题： 密度调控和Allee型随机捕捞模型中可能制度转变的识别与预防及其在鲱鱼保护中的应用 显示英文标题

标题： Recognizing and prevention of probable regime shift in density regulated and Allee type stochastic harvesting model with application to herring conservation

摘要： 一个具有多个稳定平衡的生态系统容易发生灾难性变化或从一个稳态到另一个稳态的制度转变。应注意的是，如果其中一个稳态是灭绝状态，灾难性变化可能导致灭绝。适当的管理措施可能控制不同物种从一个平衡到另一个平衡的灾难性变化的预防。我们考虑了两个具有线性和非线性捕捞项的随机模型。我们检查了密度调节或阿利型密度调节模型[Saha等，生态建模，2013]，这些模型在鲱鱼种群生存能力的研究中具有广泛的应用。我们在此考虑的确定性模型在某些限制下都包含双稳态，在这种情况下，其中一个稳定状态是灭绝状态。我们假设所考虑的动力系统是封闭的，即没有迁入和迁出。通过将常微分方程替换为随机微分方程模型，引入了人口噪声，其中确定性过程的出生率和死亡率用于获得随机微分方程中的瞬时均值和方差。我们的研究表明，通过适当选择处理时间可以手动避免灾难性变化，这最终有助于防止被采集种群的突然灭绝。整个研究通过从全球种群动态数据库(GPDD)获得的鲱鱼种群大小数据和模拟实验进行说明。 显示英文摘要

摘要： An ecological system with multiple stable equilibria is prone to undergo catastrophic change or regime shift from one steady-state to another. It should be noted that, if one of the steady states is an extinction state, the catastrophic change may lead to extinction. A suitable manual measure may control the prevention of catastrophic changes of different species from one equilibrium to another. We consider two stochastic models with linear and nonlinear harvesting terms. We inspect either density regulation or Allee type density regulated models [Saha et al., Ecological Modelling, 2013], which have substantial applications in the herring fish population's viability study. Both the deterministic models we consider here contain bi-stability under certain restrictions, and in that case, one of the stable states is the extinction state. We assume that the dynamical system under consideration is closed, i.e., immigration and emigration are absent. The demographic noise is introduced in the system by substituting an ordinary differential equation with a stochastic differential equation model, where the birth and death rates of the deterministic process are used to obtain the instantaneous mean and variance in the stochastic differential equation. Our study reveals that, the catastrophic changes can be avoided manually by a suitable choice of handling time that will eventually help to prevent the sudden extinction of the harvested population. The entire study is illustrated through the herring population size data obtained from the Global Population Dynamics Database (GPDD) and simulation experiment.