For years, special-interest groups have raised money to buy and rope off wild lands to protect them. But in June a unique partnership announced it had purchased 50,635 acres of northern California redwood forest and would preserve the land by operating it as a nonprofit business. The acquisition was funded entirely by private capital. The lead group, the Redwood Forest Foundation, Inc. (RFFI), in Gualala, Calif., claims the deal creates the first nonprofit working forest in the country and could be a model for safeguarding other natural resources.