Conservation is a state of harmony between men and land: AL was a philosopher, scientist, ecologist, forester and conservationist, and a professor at the University of Wisconsin. He was the first to describe the concept of the trophic cascade – similar to the so-called ‘Butterfly effect’ – in the natural world and his ‘land ethic’ First published in 1949, this modest account of the restoration of an 80-acre farm became a huge bestseller; this is a re-issue by Penguin Classics.