In 20 short books, Penguin Classics brings you the new canon of great environmental worksOver the past 75 years, a new canon has emerged. As humans have driven the living planet to the brink of collapse, visionary thinkers around the world have raised their voices to defend it. Their words have endured, becoming the classics that define the environmental movement today. In this lyrical meditation on the American wild lands, Leopold considers the different ways humans shape the natural landscape, and describes for the first time the far-reaching phenomenon now known as 'trophic cascades'.