I picked some of them up and got an idea of making Epic trees out of them. And here´s how they turned out...
I tried them on a piece of foam... and they looked really treelike already :)
I decided to sculpt an proper base for them from a bigger piece of foam... Just used a carpet knife on it. and glued the trees on.
I sanded the base and painted it with Steel Legion Drab, then washed it with nuln oil. Drybrush with Ushabti Bone. For the trees I used Warboss Green overbrush, then drybrush with mix of Warboss Green and Golden Yellow. Glued some grass there too... And there you have it. Simple and cheap.