It's ultradetailed model of beech trunk. It's photoscanned model made with over 200 photos, and retopologised from 3 milion faces to 120 000 faces. It was needed to save trunk details.
UVmapping was very hard to made with so many polygons but finally trunk is very detailed and rendering is very fast.
Model is textured by 8K textures:
Diffuse, Normalmap and Heightap for little displacement.
Real size is (widthxlenghtxheight) 450 cm x 450 cm x 550 cm.
Good luck with you forest renders!