Trees replanting themselves

[abt79]

In real life trees don't need humans or clay pots to continue to reproduce, they do well replanting themselves.

Why have everyday have each full size tree check in a small radius and if there are less than, say ten or so trees near it, it has a chance to will plant a small sapling of its type on a random spot in that radius.
Therefore trees can replant themselves without human help but further trees won't be planted too close together. Maybe in grassland/heath-y biomes there can be fewer trees naturally planted close bye.

Maybe the new trees could even be affected by soil quality?

[CaptainMidget]

I've noticed trees do infact replant themselves, whilst not exactly in a radius(?) in the wild.