Department of Applied Mathematics, National Pingtung University, Pingtung, ROC 90003, Taiwan.
Department of Mathematics, National Taiwan Normal University, Taipei, ROC11677, Taiwan.
Math Biosci Eng. 2019 May 31;16(5):4976-4998. doi: 10.3934/mbe.2019251.
Motivated by an age-structured population model over two patches that assumes constant dispersal rates, we derive a modified model that allows density-dependent dispersal, which contains both nonlinear dispersal terms and delayed non-local birth terms resulted from the mobility of the immature individuals between the patches. A biologically meaningful assumption that the dispersal rate during the immature period depends only on the mature population enables us investigate the model theoretically. Well-posedness is confirmed, criteria for existence of a positive equilibrium are obtained, threshold for extinction/persistence is established. Also addressed are a positive invariant set and global convergence of solutions under certain conditions. Although the levels of the density- dependent dispersals play no role in determining extinction/persistence, our numerical results show that they can affect, when the population is persistent, the long term dynamics including the temporal- spatial patterns and the final population sizes.
受一个假设扩散率为常数的两斑块年龄结构种群模型的启发,我们推导出一个允许密度依赖扩散的改进模型,该模型包含非线性扩散项和由不成熟个体在斑块之间的移动产生的延迟非局部出生项。一个合理的假设是,不成熟期的扩散率仅取决于成熟种群,这使我们能够从理论上研究该模型。我们确认了模型的适定性,得到了正平衡点存在的条件,建立了灭绝/持续的阈值。在某些条件下,还研究了正不变集和解的全局收敛性。尽管密度依赖扩散的水平在决定灭绝/持续方面没有作用,但我们的数值结果表明,当种群持续存在时,它们会影响包括时空模式和最终种群规模在内的长期动力学。