While reading the book “Poetrees,” by Douglas Florian, to students at Avon Elementary this past year, we came upon a poem about the bristlecone pine tree. One line about the tree reads, “For fifty cen-trees I’m alive.”
Reading this poem sparked the students’ curiosity. Fifty centuries? We did some quick calculations and figured out that was 5,000 years! As it turns out, the author of this poem was using a little poetic license, as the oldest known bristlecone pine, located in California, is approximately 4,600 years old.
The oldest known tree in Colorado is also a bristlecone pine (although it is a different variety than the one in California), located near South Park, and it was dated to be 2,453 years old in 2011, meaning it began its life in 442 BC!
Before long, the students and I were scouring the Internet to find photographs of the magnificent bristlecone pine. The photos we found showed single trees clinging tightly onto the tops of high barren ridges with trunks and branches that were twisted, bent, and sculpted like a flag blowing in the wind. The photographs captured the tree’s ghostly existence, of lone beings battling extreme weather and temperatures.
In fact, these trees are one of the few able to thrive in rocky limestone soils. Because of the limited nutrients, these trees typically grow as solitary sentinels on the exposed rocky cliffs. It’s fairly common for these ancient beings to be hit by and to survive lightning strikes, as the distance between them keeps the fire from spreading.
One student remarked that the trees didn’t even look alive, and indeed, many of them had trunks that appeared to be dead, with few branches or needles.
In fact, these trees have an amazing ability to continue to live while allowing some of their tissue to die off. The tree then lives off of the nutrients from its dead tissue in a weird sort of botanical cannibalism. In fact, the tree can survive with only a narrow strip of living xylem tissue in its trunk, reducing the nutrient demands on the tree’s crown.
The bristlecone’s longevity is almost a necessity in an environment that offers almost no respite from harsh conditions.
From the heavy winter snows and gusting winds to the intense summer sun, the challenges to survive in the alpine world are many. The bristlecone pine, like most alpine plants, has a set of unique adaptations that help it to thrive in such an extreme place. In some cases, the tree has the ability to enter a dormancy stage when conditions for growth are unfavorable, much like a deciduous tree in the winter.
The needles of the bristlecone pine, themselves, are also long lived, staying on the tree from 20-30 years, reducing the amount of energy devoted to producing new needles and providing a stable base for photosynthetic activity.
These trees have one of the shortest growing seasons possible, with only a handful of weeks that growth can even occur. In fact, these trees grow so slowly that a 5 foot tree might be 500 years old!
This slow growth rate means that the wood is incredibly dense, and some trees have as many as 90 rings per inch! This dense wood, combined with the thick bark, helps the tree to resist attacks from common threats, including fungus, bacteria and insects.
If you are wondering how you might catch a glimpse of these Bristlecone Pines, there are only a few sure bets. The easiest way would be to visit Walking Mountains Science Center, where there are several recently transplanted bristlecone pines in the parking island.
It’s difficult to find naturally occurring bristlecone pines though, as Colorado is on the southern end of their range (although they do extend into eastern parts of New Mexico) and the known groves are all south of Berthoud Pass, and located at elevations of 10,000 to 11,000 feet.
There are several widespread and well-known stands around South Park, northwest of Alma and on Mount Evans.
At first, I was surprised by the interest and awe that my young students showed for the old tree. But it was clear that these children had an innate respect for their elders, and that they recognized and appreciated the wisdom that comes from having lived a long time.
They were so curious about these trees, and the things they might have seen in their lifetimes. We can only imagine the tales these great trees might tell and the wisdom they might share, if only they could.
Dina Patsiavos, Avon In-School teacher and Girls in Science teacher/ coordinator, dedicates this article to her amazing Walking Mountains colleagues, family, friends, students and of course her elders who continue to inspire her life’s work.