Just as an after thought, I presume that the ramayana contains very detailed description of the vegetation (flora and fona) of the forests that rama visted. Any possibility of having them analyzed to see if they matched any particular type of region as we know it today or perhaps a thousand years before?
Mr.CHO Ramaswamy explains this in detail in the first episode of Hindu Maha Samudram. This appeared in the 2005 Jan issue of Tuglaq ifg my memory is not mistaken.