This command enables and disables (toggles) the rendering of trees. With this toggled on, trees will not be loaded/visible. This setting can result in an FPS boost.
tt
tt
If trees are visible, executing the above command will hide them. If trees are hidden, the command will make them visible again.
ToggleTrees
ToggleTrees is simply a longer version (alias) of the TT command - it has the exact same function.