LOL I’m almost two hundred percent sure it’s fine. They’re pine which is perfectly safe and even pinecones can be eaten by buns (once boiled clean). Don’t allow them anymore and check out the thread on holiday safety

you have to be careful b/c it has probably been treated with chemicals or pesticides… i’d try to block it off with NIC grids if you can so they cannot get to it anymore.

Yes it is O.K. so long as the tree is “organic” no residues etc. Here is a snippet from the Holiday Hazard thread:

Christmas Tree Hazards
It is very difficult to keep Christmas tree lights and decorations, which are irresistible to many rabbits, out of your rabbit’s reach. We recommend blocking off the area around your tree with decorative fencing.
See http://members.aol.com/Mombeanie/photogallery3.html, and the photo to the right, for a festive way to keep your rabbit away from your tree. Real pine Christmas trees that have not been treated with fire retardant spray are safe for bunnies to chew; however, note that ingesting pine can turn your rabbit’s urine orange. This is normal, and should not be a cause for concern. Do not let your rabbit drink the water in the Christmas tree stand, especially if you put sugar or soft drinks in it to help prevent the tree from losing its needles.

Be careful that you don’t have the tree sitting in that chemical liquid that extends the “greenness” of the tree – if they drink that, you have reason to worry.