Like many biological forms, tree rings speak to the imagination of both artists and scientists. To create the image at the left, Connecticut-based artist Bryan Nash Gill took a cross section of a fallen willow tree, sanded it smooth and then charred it to raise the grain. Next, he rolled ink over the wood and laid down a piece of paper to transfer the pattern. Gill's work is a way of “making the wood sing,” he says.
For dendrochronologists—scientists who analyze tree rings—each tree's story can add up to a narrative about past climate. This willow's rings have varying widths, which suggests that some years were favorable for growth and others were less so, says Connie Woodhouse, associate professor in the School of Geography and Development at the University of Arizona. The rippled rings on the right are part of a burl—an abnormal growth possibly created by some kind of infection. She also notes that the tree has two centers, which means it may have begun its life as a twin and later the siblings fused.