Posted on January 08 2018
There are a lot of ways to establish records. Hairsplitting a category can make for multiple “biggest” or “tallest” or “oldest” of whatever. Just ask Guinness—it keeps them in business. So it is with the oldest living things. There are various kinds of organisms, even if you narrow the categories down to just trees. We’ll save some of the other variations for another Geo-Joint, and focus today on the oldest living individual trees. These are the Great Basin Bristlecone Pines, Pinus longaeva, growing in California’s White Mountains, a range just east across the Owens Valley from the Sierra Nevada. Thanks to the massive Sierra, rain that comes in from the northwest gets pretty well wrung out of the clouds before they blow on over the White Mountains. So the White Mountains are fairly dry, as well as tall—at their highest point, they reach over 14,000 feet. It’s a little lower on the slopes, at the 9,000- to 11,000-foot level, that bristlecone pines make their home. It’s cold and harsh much of the year, but they seem to like it. For quite a while, the honor of “oldest of the oldest” went to a bristlecone pine named Methuselah, which has now been hanging out on those slopes for 4,847 years.
Methuselah had kin on Wheeler Peak, about 250 miles away, in Nevada. Back in the 1960s, a researcher went there to core some bristlecones to date them, but his drill bit broke off on the first tree he encountered. The tool was a hard-to-obtain item, and his grant money would soon run out if he didn’t get data to continue his study. It’s unclear whether he requested it, or if the offer was simply extended by the Forest Service, but it was decided that he could get access to the tree rings by way of….cutting the tree down. Which they did. And when the annual tree rings were counted, they came to 4,862. Because the trees don’t necessarily produce a countable ring every single year, its full age was estimated at 4,900 years. The tree, called Prometheus, had lived almost five millennia—the oldest they’d ever found—and it was now dead. So it’s little surprise, especially in this age of utterly mindless acts of vandalism (not to mention the officially sanctioned ones), that the exact location of Methusela is not public knowledge. It comes as a mild relief that in sawing down Prometheus, uncaring humans did not actually kill THE oldest living tree, because as it turns out, a bristlecone dated in 2012 has been found to be older. It’s age now is 5,065 years. Rest assured the location of that tree is also a carefully guarded secret.
How do bristlecone pines manage to live so long? Dendrologists don’t know all their secrets but have figured out some of the strategy. For one thing, the rigorous conditions they endure cut down significantly on competition from almost any other vegetation. Not much else is vying for the scant rainfall or providing fuel for wildfire. The bristlecones themselves grow in groves, but not densely, and in their more solitary placement can extend their root stuctures and crown foliage with little interference. They keep the needles on their branches for perhaps 30 to 40 years, so there is no dense mat of combustible matter collecting underneath them. The lack of rain, the severe cold, and the bitter winds drive away the insects and fungi that might bring death or disease. Their dense wood and copious resin are defenses against the bugs which do attempt to take a whack at them. Bristlecones can live on almost soil-less rock, especially on dolomite, which provides an alkaline and only weakly nutritious diet. They seem to prefer this fare, which is nowhere near enough for most plants. Limber pines, Pinus flexilis, have evolved to survive in the vicinity but prefer a somewhat warmer temperature and therefore lower elevation.
An almost otherworldly life strategy which they employ is called, “sectored architecture.” Their growth mechanism is such that should a root become a victim of disease or exposure, and die, only the bark and tissue above it will be impacted. This leads to the appearance of many bristlecones, which may display raw wood that looks sandblasted on several sides, while only narrow strips of living bark feed a few branches above healthy roots. Though the quantity of foliage on such specimens is minimal, that which still survives is fully capable of producing cones with viable seeds. This rugged tenacity to keep growing despite adversity gives brlstlecones their gnarled, twisted, iconic look. They appear to be dead, but can carry on with a fractional bit of life for centuries. Their generally short stature, not often over 50 feet, keeps their wind exposure down. Growing perhaps only an inch in girth in a hundred years, they are able to shut down during periods of extreme environmental pressure such as severe drought, maintaining only mlnimal life processes until conditions improve.
With all this in mind, when you look up “survivor” in the dictionary, there should be a picture of a bristlecone pine. They have proved their mettle not just for a century or two, but over thousands of punishing years. In the least likely of locations, they are able to grind out an existence by adapting to each survival challenge. They may soon face the rapid arrival of another test of their legendary ability to roll with the punches. Their brutal environment high in the White Mountains is likely to moderate as climate change warms the planet. The band of weather most suitable to the bristlecones may move upslope faster than the bristlecones can. And coming up from below, seeking new opportunity, are the limber pines. A warmer and wetter climate is giving the limber pines a leg up in the domain of the bristlecone. The limber pines have in fact bounded past the bristlecone’s favored elevations to spaces above 11,000 feet as well. Limber pines are no crabgrass—they grow slowly and can rack up 2,000 birthdays themselves. They are aided in their upward climb by the activities of Clark’s nutcrackers, birds that hide their seeds for later consumption, but don’t relocate them all. These birds also find the milder weather on high to be inviting. It is a slow-motion race, begun 50 years ago as average temperatures began to climb. But it’s slow-motion only to human-centered time frames. In bristlecone-time, it’s coming fast, and as the effects are becoming more evident, the bristlecones must be ready to adapt again.
Travel the incomparable US Highway 395 along the Eastern Sierra, and turn off to see the White Mountains and the bristlecones! This Benchmark map, available from Maps.com, will lead you there:
source: Wikimedia Commons: Famartin (CC by SA 3.0 Unported)
source: Wikimedia Commons: Jane S. Richardson (CC by SA 3.0 Unported)