Science Diaries: Tree Rings Natural Archive
Ambiance: Pantanal – Dawn chorus
EC: Trees represent, without question, the most readily available archive of annual information about environmental change in the world.
JM: You can certainly turn trees into paper for archiving information, but there’s a whole store of data inside a tree itself. Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside. Edward Cook is director of the Tree Ring Laboratory at Lamont Doherty Earth Observatory in Palisades, New York.
EC: What makes the science of dendrochronology so fascinating is that it’s enormously useful for lots of different studies. We can date the constructions of old buildings, of archeological ruins and things like that. For example, the entire series of cliff dwellings and pueblos in the four corners area of the southwestern United States was dated by dendrochronology. We know precisely the building history of all those dwellings. We can look at long-term stream flow from tree rings, we can reconstruct river runoff. We can look at insect attacks on trees. We can look at the effect of air pollution on tree growth through tree ring analysis. It goes on and on.
JM: Variations in tree rings can shed light on a host of environmental conditions for each year of the tree’s life. But it’s up to scientists to ask the right questions.
EC: You may use the tree rings for a particular purpose today, and then 20 years from now, somebody will turn around and say, gee whiz, you know, I can use the same data to tell me something else that was not envisioned. A grad student here at the tree ring lab, in fact, is doing that very thing right now, he’s dug out many of my samples from the early 1980s, and found some very, very interesting long-term growth trends that have confounded a lot of forest ecologists. I never thought about using them that way. So it just shows the importance of preserving these specimens, because they can be used in unforeseen ways in the future.
JM: Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.