Statistical Properties of Multispecies Competition Ecosystems Subjected to Dichotomous Noises

• Published in: Communications in theoretical physics 2011-05, Vol.55 (5), p.829-834
• Main Authors: Nie, Lin-Ru (林如 聂), Peng, Jin-Hui (金辉 彭), Mei, Dong-Cheng (冬成 梅)
• Format: Article
• Language: English
• Subjects: 人口密度; 噪声统计特性; 平均场近似; 概率分布; 生态系统; 种群竞争; 表达分析; 非对称
• ISSN: 0253-6102
• DOI: 10.1088/0253-6102/55/5/18

We investigate statistical properties of multispecies competition ecosystems subjected to both symmetric and asymmetric dichotomous noises. The expression of the stationary probability distribution function （SPDF） is analytically derived by means of mean-field approximation, and verified by stochastic simulations. The results indicate that： （i） A noise amplitude （a0）, a noise autocorrelation time （τ0） and a noise symmetry parameter （k） all can affect the SPDF; （ii） There is an optimal τ0, which makes the mean value of population density be maximal, near which a transition takes place, i.e., the stationary mean value of species density （（x）st） suddenly falls to a lower constant, （iii） As k decreases, the maximum of （x）xt and the optimal 70 increase. The parameter planes of TO -- a20 and τ0- k for the transition are plotted.