Mannahatta: A Natural History of New York City Eric W. Sanderson Abrams, $40The Manhattan of today, a narrow island no more than 12 blocks wide, brims with 1.6 million people who journey in cars, buses, and trains through valleys of steel, glass, and concrete. When Henry Hudson landed on this forested isle 400 years ago in his quest to find the Orient, it teemed with ecology of a different sort. Mannahatta: A Natural History of New York City, by the landscape ecologist Eric W. Sanderson, vividly conjures this Island of Many Hills, as the native Lenape Indians called it; he uses as his source material sketches made by settlers in the early 1800s and, perhaps most significant, the magnificently detailed British Headquarters Map, completed around 1783. "When I looked at the British Headquarters Map," Sanderson writes with a contagious sense of wonder, "I saw in the markings for ‘salt grass fields' the great green swards of salt marshes on the Lower East Side; in wavy blue hachures I saw red maple swamps in Times Square and precious bogs in Central Park." Contemporary Manhattan, he observes, is "a place where humanity has completely triumphed over the natural world." The brilliance of Mannahatta, however, is to reveal this transformation. Sanderson combines old-fashioned scholarship and advanced cartography software to overlay (block by block) and juxtapose the modern city with its primordial past. The later chapters are an exercise in imagining the future. Sanderson envisions a city 400 years hence where there are no automobiles; natural streams have been restored; wind turbines perch on building tops. Given the transformation of Mannahatta since 1609, who's to say this vision of 2409 is not within our grasp?