The ecology that I grew up with described a repetitive sequence wherein a forest that had been eliminated by fire or lumbering would gradually return to its former state. Grasses would be followed by shrubs. Shrubs would be followed by pioneer trees such as sumac, black locust, sassafras and black cherry. Finally a forest dominated regionally by various hardwoods and white pine would compose the final climax forest, to remain for evermore unless eliminated by some future event of total destruction. No doubt this concept was never fully accepted and now the skeptics have come to the fore and say convincingly that there is no such thing as a climax forest in the purest sense.
Life responds to an ever changing environment and some things prosper and some things lose out.
A case in point comes to mind. Back in the late 40's I studied wildlife management at Michigan State University. Then as now the white tailed deer was a foremost concern. Lack of sufficient food over winter resulted in many deaths. Deer obtained much of their winter food from swamps with pure stands of white cedar.