Throngs of people walk through Central Park each year barely noticing the thousands of trees which give it its natural flavor. Ken Chaya, with his colleague Ned Barnard, has spent the last two years counting and mapping 19,933 trees to publish ‘Central Park Entire: The Definitive Illustrated Folding Map’. Host Bruce Gellerman learns about the landscape’s history, design and botanical value in a short stroll around the park. Photo: American Elm (