Propagation Dynamics for a Stage-Structured Population Model in a Shifting Environment

In this paper, we study an integro-difference system in an unbounded domain for a population with a stage structure consisting of juveniles and adults. The environment shifts between a favorable habitat and an unfavorable habitat at two ends of the domain, which makes the growth and propagation dynamics of the population depend on the changing habitat conditions. Under appropriate assumptions, we established the existence of spreading speeds and forced traveling waves for such a model. Our analysis of the propagation dynamics is based on the corresponding limiting systems at the far ends of the domain and their relation to the model. It turns out that the habitat shifting speed greatly influences the spreading speeds of the population and may even cause the extinction of the population.