Dota 2 tree mods
Trees are their own mod because people mix them: the ground from one author, the trees from another. They load ahead of a terrain, so a tree mod wins over the trees a terrain ships.
The D2PFX catalog has 20 mods in this category. Each changes what you see on your own screen; everyone else sees their own game.
Virus Trees
Deathrun Eggs
Catbuns Trees
Cone Trees
Gravestones Trees
LowPoly Barrel Trees
LowPoly Shrub Trees
LowPoly Skull Trees
LowPoly Stumps Trees
LowPoly Trees v1
Metal Barrel Trees
Pine Cone Trees
Small Trees Minify
Logs Trees
Cartoon Trees
Crystals Trees
LowPoly Trees
Pumpkin Trees
Stone Trees
Wooden Trees
Installing any of these
Open Dota 2 Mod Manager, find the hero, press Install. The app puts the file in a free pak slot in the folder your game mounts, tells you when two mods carry the same file, and puts everything back after a Dota patch. The full guide, or the manual route if you would rather do it yourself.