Hi Guys !
Cleaning up my files and came up on this that was done 2 years ago to permit some control on where specific trees land and built this complex of nodes for 10 distribution finals with no overlap and possibility of restricting to slope and altitude with also possible additional restriction by painted or distance shader.
I include a crude example of different trees and the tgc file which has an internal network so as to reduce clutter. Also included a note in there.
This may be totally useless...but you be the judge !
Take Care !
Paul