[en] Systems ecology techniques have been useful in simulating the fate and dynamics of radionuclides in forest ecosystems. The applications of systems models in this context are twofold: projection of the time-dependent distribution of radioisotopes among various ecosystems components, and manipulation of the modeled system to determine the sensitivity of components to variation in transfer coefficients and, thereby, identify critical fluxes affecting system behavior. The present paper describes a systems model that projects the possible fate of plutonium in a deciduous forest ecosystem. The isotopes of interest are ²³⁹Pu and ²⁴⁰Pu which have physical half lives of 2.44 x 10⁴ and 6540 years, respectively. These isotopes are indistinguishable by alpha spectrometry hence ²³⁹Pu is used to refer to both