Friday, February 12, 2010
If you want to put human history into perspective, just reflect on the bristlecone pine. High up in the White Mountains of California is a tree that the US Forest Service has chosen to call "Methuselah," because it is oldest known tree in the world. It's almost an insulting moniker, to tell the truth. Methuselah of the Bible was reported to be 969 years old when he died. When the Methuselah tree was a mere 969 years old, there wasn't even a Bible yet. There was no code of laws from Hammurabi yet and it would be at least another 800 years before the House of David ruled in Judah; bronze represented the peak of the metallurgical arts. That's what we call ancient history, when this tree was already nearly a thousand years old. If the core samples are correct, the Methuselah tree sprouted in the year 2831 BC, before the Egyptians had gotten around to thinking, hey, we could stack some towers on top of each other and call them pyramids.
It's one of the few experiences that I consider awe-inspiring - contemplating a living thing whose lifespan has encompassed almost all of what we consider the History of Civilization. When I first encountered the sequoias, their age always impressed me even more than did their size. Some of them are well over 3000 years old, about the age that King David would be if he could have kept adding growth rings down to the present. Amazing, yet the oldest sequoias are young compared to the oldest bristlecones.
The tree in the photo above might be Methusaleh , although it probably isn't. When you visit this grove, the Forest Service literature explains that they're just not going to tell you which tree is the oldest one, because there are a lot of assholes out there who might think it cute to vandalize such a special tree, and for all they know, you might be one of those assholes, so you're just going to have to get by without knowing for sure. They're more diplomatic about it, but that's what they really mean, and they're entirely correct, of course.
The most amazing thing about bristlecones is how underwhelming they are on first sight. Even the oldest - especially the oldest - are just rather squat and twisted, thick but short. The oldest trees live in dry conditions and add only a thin ring of growth every year, resulting in a dense wood that resists decay and insect infestation. Many of them have been nearly girdled, with only a narrow strip of bark keeping the entire tree alive; if you look at the photo again, you'll see that most of the bark is gone, yet the tree still lives.
Because they preserve so many years of growth rings, bristlecones are a perfect subject for dendrochronology, the science of discerning the patterns of wet and dry years by identifying the wide and thin rings in trees. The living tree allow you to peg the record to the present day, while the rings of long-dead trees can be matched up with those living trees to push the record back even farther, in some regions back to 10,000 years with accuracy to the very year. It's an impressive climatic record. At the top of this post, I had to use ancient Near East history to provide context for the Methuselah tree, because no comparable written records exist for California. But there is a historical record there, nonetheless. The bristlecone pines have witnessed thousands of years of that history and are still able to tell us about some of it.