Although humans have probably tried to repair ecological damage and improve their local environment for as long as we have recognized the effects of careless use of our natural resources, restoration ecology is a relatively new field that attempts to combine practical knowledge of land management with the scientific insights of academic disciplines such as ecology, wildlife management, landscape architecture and horticulture. A pioneer in this field was the noted author and wildlife ecologist, Aldo Leopold, whose Sand County Almanac presents his ethical code for land stewardship together with practical experiments in restoring worn out, sandy farmland in central Wisconsin. The farm was far from a pristine wilderness, nor were the Leopold family merely spectators on it. They regarded themselves as active participants and citizens of the land community, seeking to restore the land to ecological health and beauty. "Conservation," Leopold wrote, "is the positive exercise...