Coexistence, Extinction, and Optimal Harvesting in Discrete-Time Stochastic Population Models
Coexistence, Extinction, and Optimal Harvesting in Discrete-Time Stochastic Population Models
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离散时间随机种群模型中的共存、灭绝和最优收获
DOI：
10.1007/s00332-020-09667-0
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发表时间：
2021
影响因子：
3
通讯作者：
Hening, Alexandru
中科院分区：
文献类型：
--
作者：
Hening, Alexandru
我们分析了可以通过收获控制的相互作用种群的长期行为。动态被假定为离散的时间和随机的，由于环境波动的影响。我们提出了强大的灭绝和共存的标准时，有一个或两个相互作用的物种。然后，我们使用这些工具，以了解何时收获导致物种灭绝或持续存在，以及最佳收获策略，最大限度地提高预期的长期产量，看起来像什么。对于单种群系统，我们证明了在一定条件下，最优收获策略是bang-bang型的：存在一个阈值，在该阈值下没有收获，而在该阈值以上的一切都被收获。我们还能够表明，随机环境波动，在大多数情况下，迫使预期收获产量低于确定性的最大可持续产量。本文的第二部分是关于生态系统的分析，有两个相互作用的物种，可以收获。特别是，我们仔细研究捕食者-猎物和竞争力的Ricker模型。我们能够分析确定的区域中的参数空间中的物种共存，一个物种持续存在，另一个灭绝，以及当有双稳态。我们看看如何找到最佳的比例收获策略。当系统为捕食-食饵系统时，最优比例收获策略是根据相互作用参数和捕食者相对于食饵的价格，将捕食者收获至灭绝并最大化食饵的渐近收获量，或者不收获食饵并最大化捕食者的渐近收获量.如果系统是竞争性的，在某些情况下，最优的做法是使一个物种灭绝，并收获另一个物种。在其他情况下，最好让两个物种共存，在保持共存的同时收获两个物种。在竞争Ricker模型的背景下，我们证明了如果一个竞争者是优势的，并推动其他物种灭绝，优势物种的收获可以导致共存。
We analyze the long-term behavior of interacting populations which can be controlled through harvesting. The dynamics is assumed to be discrete in time and stochastic due to the effect of environmental fluctuations. We present powerful extinction and coexistence criteria when there are one or two interacting species. We then use these tools in order to see when harvesting leads to extinction or persistence of species, as well as what the optimal harvesting strategies, which maximize the expected long-term yield, look like. For single species systems, we show under certain conditions that the optimal harvesting strategy is of bang-bang type: there is a threshold under which there is no harvesting, while everything above this threshold gets harvested. We are also able to show that stochastic environmental fluctuations will, in most cases, force the expected harvesting yield to be lower than the deterministic maximal sustainable yield. The second part of the paper is concerned with the analysis of ecosystems that have two interacting species which can be harvested. In particular, we carefully study predator–prey and competitive Ricker models. We are able to analytically identify the regions in parameter space where the species coexist, one species persists and the other one goes extinct, as well as when there is bistability. We look at how one can find the optimal proportional harvesting strategy. If the system is of predator–prey type, the optimal proportional harvesting strategy is, depending on the interaction parameters and the price of predators relative to prey, either to harvest the predator to extinction and maximize the asymptotic yield of the prey or to not harvest the prey and to maximize the asymptotic harvesting yield of the predators. If the system is competitive, in certain instances it is optimal to drive one species extinct and to harvest the other one. In other cases, it is best to let the two species coexist and harvest both species while maintaining coexistence. In the setting of the competitive Ricker model, we show that if one competitor is dominant and pushes the other species to extinction, the harvesting of the dominant species can lead to coexistence.
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影响因子：
2
作者：
P. Crowley
通讯作者：
P. Crowley
离散总体模型中混沌和随机稳定性的统一框架
DOI：
--
发表时间：
1997
期刊：
影响因子：
--
作者：
M. Vellekoop;G. Högnäs
通讯作者：
G. Högnäs
随机种群的收获和播种：分析和数值近似
影响因子：
1.9
作者：
Hening, Alexandru;Tran, Ky Quan
通讯作者：
Tran, Ky Quan
影响因子：
1.9
作者：
Alexandru Hening;D. Nguyen
通讯作者：
Alexandru Hening;D. Nguyen
捕食者介导的共存与灭绝☆
DOI：
--
发表时间：
1981
期刊：
影响因子：
--
作者：
S. Hsu
通讯作者：
S. Hsu