ABSTRACT
Everyone agrees that “sustainable” management of our farms, forests, and rangelands is desirable; but it is hard to find a definition of sustainability on which everyone can agree. An extreme view is that the only kind of resource harvesting that is sustainable is that of aboriginal hunter-gatherers in the rain forest, who live in a closed ecosystem where nothing is artificially imported into the ecosystem, and where, therefore, there is no pollution. Nothing is transported out of the ecosystem, so there is no depletion. Everything is recycled, and natural soil erosion is so slow that losses are replaced by natural soil-forming processes. Such systems, however, can only support a limited human population, and only in areas with fertile soils and abundant rain.
