Little change in topic (my apologies)
But I reckon Tolkiens Forests in 'the Lord of the Rings' are awe-inspiring.
From what I know, some trees (according to the Ent Treebeard in the novel) have dates back to the First Age the "Old World" of Middle Earth...the First Age to the end of the Third Age spans over 14,000 years!!
Imagine the character of those trees! Their mysterious power, their archaic past...
Trying to capture the image of a tree that is ravaged by ancientness and the changing world world without the mechanisation of industrialisation. A tree that has bears the burdens of Middle Earth.
There are certainly no limits to the Tolkiens trees and forests, why, one can create an Ent with two trees that are twisted together, all gnarled and the nebari are the Ents' toes and you can have some nebari grown over a dead Orc like as though the Ent has destroyed it...an expression of the Ents' hate for axe wielding Orcs perhaps?
and Treebeard (Treebeard on Bonsaitalk

) ceated an absolutely awesome Hobbit Hole landscape.
Goodness, I can sculpt the city of Minas Tirith out of limestone, create some form of drainage and plant the White Tree of Gondor right on top! (in proportion of course!)
Just my little rabble and two cents on LOTR trees
I don't really mind too much on rules, just so long as I can still have freedom and step outside the boundaries, thats all that matters. I like the Japanese Style for its neatness and the "free-form" ways cause I can absolutely pour out my insane imagination.