system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Places like Michigan were logged of their native pines in the late 1800s - early 1900s. Leafy trees largely replaced them. On a long enough timeline, would the forests return to their original state, or is the change in composition permanent?
gpt
If you look at forests in the Rocky Mountains, they go through this kind of transition every 30 years or so.  The quick growing Aspen trees shoot out of the ground and form a protective barrier for the pine seedlings as they get a foothold.  Just as the pine trees are getting big enough to start needing more space, the Aspens get old and die off, leaving growing room for the Pines to get big.

Overall though, there's evidence that forests aren't the 'natural' state, and the loss of large animals like Mammoths led to an expansion of forested areas.  It's probably better to think of the leafy trees as a transition point until the next ecology change hits.