Command to respawn/regrow a tree?
hope the are a plugin for this :3
'spawn tree' in console
If you type in the ServerConsole 
" del assets/bundled/prefabs/autospawn/resource " 

you clean/remove all child objects of resource from the map, which includes all trees.

Basically u can then just wait, to regrow.  or u fill in the spawn population

spawn.fill_groups

spawn.fill_populations