应用数学和力学2013，Vol.34Issue(2)：162-171,10.DOI:10.3879/j.issn.1000-0887.2013.02.006
噪声和生存环境对捕食生态系统的影响
Effects of Noises and Habitat Complexity in the Prey-Predator Ecosystem
摘要
Abstract
To explore the habitat complexity and random environmental factors effects to the ecosystem, a new stochastic predation type ecosystem with habitat complexity was proposed. Both theoretical analysis and numerical analysis were explored. With the assumption of weak disturbances, the stationary probability density functions (PDF) for both species were obtained by applying the Stratonovich-Khasminskii averaging principle. The accuracy of the results ob-tained from theoretical method was demonstrated by those obtained from Monte Carlo simula-tion (MCS). The system mean first passage time (MFPT) was solved from the Pontryagin equation. The effects of the habitat complexity and the noise intensity were investigated via nu-merical calculations based on the data obtained from experiment. Results obtained show that: 1) the ecosystem with smaller habitat complexity is less stable when the system is disturbed by noises; 2) the stronger the noise intensities are, the less stable the ecosystem will be; 3) the e-cosystem with bigger habitat complexity has longer MFPT; 4) the noise added to the prey natu-ral increase rate has a bigger effect on the MFPT than that added to the predator natural death rate does.关键词
随机生态系统/稳态概率密度/平均首次穿越时间/生存环境复杂Key words
stochastic ecosystem/stationary probability density/mean first passage time/hab-itat complexity分类
自科综合引用本文复制引用
徐伟,戚鲁媛,高维廷..噪声和生存环境对捕食生态系统的影响[J].应用数学和力学,2013,34(2):162-171,10.基金项目
国家自然基金资助项目(11172233 （）
10932009 （）
61171155) （）
陕西省自然科学基金资助项目(2012JM8010) （2012JM8010）
