2000/09/13 by Ugo Bastolla, U. Bastolla, Bastolla, U. +8
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Environmental Science · Physics and Astronomy · #Adaptation and Self-Organizing Systems (nlin.AO) #Animal Ecology and Behavior Studies #Evolution and Genetic Dynamics #FOS: Biological sciences #FOS: Physical sciences #Plant and animal studies #Quantitative Biology (q-bio) #nlin.AO #q-bio
paper · pdf · doi:10.48550/arxiv.nlin/0009025
24 pages, 20 figures
arxiv created 2000/09/13 · openalex publication_date 2000/09/13 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study a dynamic model of ecosystems where immigration plays an essential role both in assembling the species community and in mantaining its biodiversity. This framework is particularly relevant for insular ecosystems. Population dynamics is represented either as an individual based model or as a set of deterministic equations for population abundances. Local extinctions and immigrations balance in a statistically stationary state where biodiversity fluctuates around a constant mean value. At stationarity, biodiversity increases as a power law of the immigration rate. Our model yields almost power law species area relationships, with a range of effective exponents in agreement with that observed for biodiversity of whole archipelagos. We also observe broad distributions for species abundances and species lifetimes and a small number of trophic levels, limited by the immigration rate. These results are rather robust with respect to change of description level, as well as change of population dynamic equations, from prey dependent to ratio dependent.