LTS, By "earth closet," do you mean "outhouse?" If so, the problem it causes -- at least, if it's the really old fashioned kind -- is that it leaks too much nitrogen (and other things in fecal matter) into the ground water. Same problem we now have from folks using too much fertilizer on their lawns and gardens and farms, even if the fertilizer is organic (e.g., manure). Seems like the waste would need to be properly composted first and, even then, used judiciously.

BTW, among the species that depend on fire for perpetuating themselves are the giant redwoods and certain pines (ponderosa, I think). PBS very recently had a 2-hour special on the history of forest fire policy in the US, dealing with the origins of the no-burn policy, then the let-it-burn policy, backfire setting, catastrophic fires, etc. Very informative.

Genie