NatureManufacture has recently released a huge set of scanned assets, which will help you to build incredible 3d environments.
The pack includes:
• 8 fir trees (with few bark variants)
• 7 poplar trees
• 12 rocks (with auto -cover, uv free and standard variants)
• 26 grass models
• 47 ground materials
• 2 trunks
• 6 roots
• Tesselated landscape material with UV mix function
• Demo scene from video
You can find more details about the pack here. Do try it, if you are looking for some interesting natural photogrammetry assets.