Climaxes can be climatic or related to other disturbances like fire, pests or windthrow. Climax communities ultimately succumb to rarely occurring and catastrophic disturbances. Black spruce gets dwarf mistletoe which ultimately leads to wildfire. White cedar gets windthrown and if patches are large enough leads to wildfire. Maple-basswood is same scenario as cedar.
Balsam fir gets spruce budworm which can lead to wildfire.
Some species of woody plants are much better adapted than others to complete their life cycle in a fire-prone environment. Most forested areas have been burned periodically. Here in Minnesota, trembling aspen, jack pine and black spruce are perpetuated by fire on many sites. Catastrophic fire stimulates aspen suckering and is the reason aspen is so widespread in the current landscape. The serotinous cones of Jack pine enable it to rapidly colonize the burned site.