Field Nui is actually a misleading name, due to the fact that approx. 40% of it is desert. The part of it that isn't desert or water, however, stays true to it's name. There are absolutely no trees, and no rivers because there are no mountains or elevation changes to propagate them.
Almost nobody lives on Field Nui, due to the disadvantages noted above. The only current residents are The comic maker Radiance and his singular character Sir Umadbro.