I'm doing a tree-only survival thing on my server. I need a plugin that damages the player if they touch dirt, grass, stone, coal ore, iron ore wooden planks, etc.. I want the damage to be slow (approximately the same effects as starving). Good luck!
https://www.dropbox.com/s/8w34uc94k83whbc/TreeServer.jar Should do the trick, people with Tree.noHurt permission get hurt by EVERYTHING except leaves