On the principle of competitive exclusion in metapopulation models
  In this paper we present and analyse a simple two populations model with migrations among two different environments. The populations interact by competing for resources. Equilibria are investigated. A proof for the boundedness of the populations is provided. A kind of competitive exclusion principle for metapopulation systems is obtained. At the same time we show that the competitive exclusion principle at the local patch level may be prevented to hold by the migration phenomenon, i.e. two competing populations may coexist, provided that only one of them is allowed to freely move or that migrations for both occur just in one direction. 
Davide Belocchio, Roberto Cavoretto, Giacomo Gimmelli, Alessandro   Marchino, Ezio Venturino
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