School of Management Engineering, Zhengzhou University of Aeronautics, Zhengzhou 450046, China.
School of Economics, Zhengzhou University of Aeronautics, Zhengzhou 450046, China.
J Theor Biol. 2023 Sep 21;573:111610. doi: 10.1016/j.jtbi.2023.111610. Epub 2023 Aug 20.
In this paper, a single species model with Allee effect driven by correlated colored noises is proposed and investigated. The stationary probability density of the model is obtained using the approximative Fokker-Planck equation, and its shape is discussed in detail. P-bifurcation and noise-induced bistability are explored, followed by the observation of noise-enhanced stability through mean first passage time analysis. Our findings demonstrate that: (i) noise can induce P-bifurcation, causing the structure of a stationary probability distribution to shift from unimodal to monotonic under positive correlation and switch from unimodal to bimodal under negative correlation; (ii) correlation time promotes population growth, leading to a higher probability of large population size and delaying the extinction process; (iii) noise-enhanced stability induced by multiplicative noise depends on both additive noise and correlation time, while it always exists for additive noise.
本文提出并研究了一个由关联色噪声驱动的具有 Allee 效应的单物种模型。利用近似的福克-普朗克方程得到了模型的稳态概率密度,并详细讨论了其形状。探讨了 P 型分岔和噪声诱导的双稳性,然后通过平均首次通过时间分析观察到噪声增强的稳定性。研究结果表明:(i)噪声可以诱导 P 型分岔,导致稳态概率分布的结构从单峰到单调在正相关下发生变化,从单峰到双峰在负相关下发生变化;(ii)相关时间促进种群增长,导致大种群数量的概率更高,并延迟灭绝过程;(iii)乘性噪声引起的稳定性增强取决于加性噪声和相关时间,而对于加性噪声则始终存在。