Global dynamics of a two-stage structured diffusive population model in time-periodic and spatially heterogeneous environments

This work examines the global dynamics of classical solutions of a two-stage (juvenile–adult) reaction–diffusion population model in time-periodic and spatially heterogeneous environments. It is shown that the sign of the principal eigenvalue ${\lambda }_{\ast }$ of the time-periodic linearized system at the trivial solution completely determines the persistence of the species. Moreover, when ${\lambda }_{\ast }>0$, there is at least one time-periodic positive entire solution. A fairly general sufficient condition ensuring the uniqueness and global stability of the positive time-periodic solution is obtained. In particular, classical solutions eventually stabilize at the unique time-periodic positive solutions if either each subgroup's intrastage growth and interstage competition rates are proportional, or the environment is temporally homogeneous and both subgroups diffuse slowly. In the latter scenario, the asymptotic profile of steady states with respect to small diffusion rates is established.