In this paper, we study the integrability problem of a mathematical models of forests with two age classes of the form, ẋ =ρy − (y − 1)²x − sx, ẏ = x − hy, where ρ, h, s ∈ R. We proved that the system has a unique Darboux polynomial if and only if ρ = 0. The model has only two or three exponential factors if h ≠ 0 or h = 0, respectively. It is also, showed that the system admits a Darboux first integral if and only if ρ = h = 0 and has no analytic first integral in any neighborhood of fixed point except when ρ = h = 0.
