Conservation

con·ser·va·tion
noun: conservation the action of conserving something, in particular.
preservation, protection, or restoration of the natural environment, natural ecosystems, vegetation, and wildlife.
Usage, improvement, and protection of human and natural resources in a wise manner, ensuring derivation of their highest economic and social benefits on a continuing or long-term basis. Conservation is achieved through alternative technologies, recycling, and reduction in waste and spoilage, and (unlike preservation) implies consumption of the conserved resources.