Conservation is an ethic of resource use, allocation, and protection. Its primary focus is upon maintaining the health of the natural world, its fisheries, habitats, and biological diversity. Secondary focus is on materials conservation, including non-renewable resources such as metals, minerals and fossil fuels, and energy conservation, which is important to protect the natural world. Those who follow the conservation ethic and, especially, those who advocate or work toward conservation goals are termed conservationists.
(From Wikipedia, February 2015)