Ecosystems with migrations
We have improved our ecological model to support several simultaneous ecosystems at a time. Species can migrate between ecosystems. Two types of migration have been implemented :
- Migration due to overpopulation.
For the overpopulation case, the migration target is chosen between all the ecosystems in the simulation, the migrating species choosing the ecosystem with less individuals of the same species, to minimize competition. For the seasonal case, species migrate to the first ecosystem in spring, and to the second ecosystem in winter.
The information associated to a generic species (food preference coefficients, type of migration it performs, ...), is encapsulated in a class called MSpecies. Another class ( Population) represents the behavior of a particular species on a particular ecosystem, containing the initial and actual number of individuals, a reference to the generic species it belongs, etc. Each ecosystem has been modeled as a collection of populations. Except for migration, each population only interacts with those species at the same ecosystem.
The model we describe here consists of three ecosystems. One of them is in equilibrium, and includes three species (Lions, Gnus and Grass). The other two are not in equilibrium and include four species (Lions, Gnus, Zebras and Grass). We can observe an invasion of the Zebras in to the first ecosystem, that breaks its equilibrium.
Last modified 21/12/99 by Juan de Lara ( Juan.Lara@ii.uam.es, http://www.ii.uam.es/~jlara) need help for using this courses?.
The OOCSMP code - The SODA code