Why not? It sounds like you are saying the carbon released by cutting/burning one mature tree is more than that captured by the planting and eventual growth of one tree. It seems non-sensical on the surface, but maybe I'm missing something. Maybe you're arguing that the carbon release is instantaneous but the carbon capture takes decades?
From an atmospheric CO2 standpoint, perhaps all trees (of a given carbon mass) are equivalent. But the monocultures that we plant are a pathetic, precarious substitute for natural habitat.