This is the scene with everything but trees disabled.  955 trees.  LOD and billboard quality at lowest.  1826 draw calls 997 batches.  Disable the tree root object and goes down to 41 draw calls.

I'm very far away and LOD cranked all the way down, it's just billboards rendering.  You should be able to replicate this easily by just switching unity to deferred and then updating the demo scene camera and manager to deferred. Then clicking best performance button in demo.  The difference is obvious regardless of settings or where the camera is, it'st that big.