Have had the same desire for an open-air burial myself, for the strange reason that I claustrophobic and don't want to be trapped in a coffin. Thought of cremation, being roasted, isn't so pleasant either. However, did you know that followers of the Parsi religion in India have towers where they leave the dead for birds to feed on? Also, of course, the Native Americans of some tribes (I don't know which) would put their dead up in trees and also allow the birds and wild animals to eat them. It is a way of returning the body to nature. Rohinton Mistry comically portrayed the problems of Parsi body-disposal to the surrounding community in a scene in one of his books. Sorry, again, don't remember which, but it was funny in a morbid way.