system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When you see a lone tree growing in a meadow, what’s preventing other trees from growing nearby?
gpt
Historically, farmers would clear frees to make larger more efficient fields.  But before tractors, they would leave a small number of trees behind to provide shade during breaks for themselves and their horse or ox.

It was a compromise between pure crops and having a bit of shade at break time.