I haven’t had the chance to get my hands on the game during the beta, but looking at some gameplay video, something appeared to me :
The trees seem to be indestructible. In this video, at several moments, you can see the tank “moonwalking” in place, desperately trying to push through some small trees : https://youtu.be/lSttBSIe4kM?t=325
I think a several tons robot should have no problem pushing those little twigs aside and crushing them under its feet. Of course larger trees are a different issue, and those might as well be indestructible.
Of course, I have no idea what the game engine’s limitations are, but if that’s within the realm of possibilities, it’s definitely something I’d like to see implemented. It seems easy at the moment to trap the tank in a small grove and have it be a sitting duck.