The Oak Tree: Essential to Life on Earth

Forgetful blue jays collect and disperse acorns in preparation for winter, while slave-making ants barricade their colonies within the hard shells. In the meantime, leaf litter prevents floods and roots send carbon dioxide into the ground for thousands of years, making oak trees not only an environmental wonder, but an ecological necessity. Guest: Douglas Tallamy, author of "The Nature of Oaks: The Rich Ecology of Our Most Essential Native Trees"