Aldo Leopold (January 11, 1887 – April 21, 1948) was an American author, philosopher, scientist, ecologist, forester, conservationist, and environmentalist. He was a professor at the University of Wisconsin and is best known for his book A Sand County Almanac (1949), which has sold more than two million copies.
Leopold was influential in the development of modern environmental ethics and in the movement for wilderness conservation. His ethics of nature and wildlife preservation had a profound impact on the environmental movement, with his ecocentric or holistic ethics regarding land. He emphasized biodiversity and ecology and was a founder of the science of wildlife management.