I wonder who will plant a tree? A squirrel buries an acorn. A dolphin pushes a coconut into an ocean current. A camel chewing a date spits out the seed. What do they all have in common? Each one, in its own way, has helped to plant a tree. In myriad ways and diverse environments, Mother Nature is given a hand in dispersing seeds that eventually grow into trees. From the apple seeds falling off the sticky fur of a black bear...