The problems of the asymptotic behavior of age-dependent population mo
dels with interior and spatial structures are considered. It is proved
that the existence and uniqueness of the stable state and its exact f
orm is founded for general linear models. Problems on the speed of con
vergence to stable state and transitional effects are investigated. Me
thods of solving two special classes of nonlinear models (separate mod
els and models of the Gurtin-MacCami type) are suggested. A model of f
orest stand dynamics on the basis of conception of layer-mosaic charac
teristics of the spatial-temporal structure of stands is examined as a
n example of the application of given results.