Underground Forests

I would very much like to see two new biomes to go with the Deep Dark update. I was thinking over the fact, and I thought how cool it would be if there were underground forests! I was thinking that there could be spruce/oak/birch, maybe jungle trees in large caverns near the surface (a light opening at the top of the cave would be awesome) with rivers, and maybe a lush cave mixed in. I also thought it would be awesome to have giant mushroom forests down in deep large caverns, maybe with some glowing variants! There could be new mobs like fungal cave bats and such, and floating spores would be cool as well (a different color than the spore blossom, which is an absolutely amazing Minecraft object btw) Thank you for considering my ideas!

P.S. totally unrelated, but I think Java combat would be great in bedrock