Dynamics of closed ecosystems described by operators

•Linear and nonlinear models of closed ecosystems.•Fermionic operators for the description of classical systems.•Numerical simulations.

We adopt the so-called occupation number representation, originally used in quantum mechanics and recently adopted in the description of several classical systems, in the analysis of the dynamics of some models of closed ecosystems. In particular, we discuss two linear models, for which the solution can be found analytically, and a nonlinear system, for which we produce numerical results. We also discuss how a dissipative effect could be effectively implemented in the model.