Come with me to the Rocky Mountains of the southwestern United States. Climb with me to a height of 8,000 feet (2400 m). Here we come upon a gnarled, twisted tree, so bent over that some of its uppermost branches practically touch the ground. A large part of the tree is nothing but dead wood.
On this side of the poor old tree, however, we find a strip of living bark. This living portion connects with the branches that still carry green leaves. Obviously, that strip of living bark is still able to transport life-giving sap from roots to leaves.
Can we fathom how many centuries have come and gone during the lifespan of this gnarled tree? Scientists have taken borings of the dead portion. By counting the growth rings, they have determined it must be between 4,000 and 5,000 years old!
What makes it possible for certain trees to live this long? First, these old specimens are always found in cool, dry areas where there aren’t many insects and diseases. As you well know, Wondernose, tiny insects can cause the death of a tree, or whole forests, for that matter.
We can see another reason in the fact that this old, gnarled tree was able to survive even though a large part of it had died off. Not all trees have that ability.
Then, too, there is the matter of this old tree’s remarkable leaves. I’ve been calling them leaves, and that is correct, but you would no doubt call them needles.
Yes, Wondernose, that gives away a secret—our mystery tree is a pine. What’s remarkable about this particular tree’s needles is that they last a long time, needing to be replaced only every fifteen to thirty years. Thus, if there are years of drought, the tree need not be stressed to produce lots of new needles. Most evergreen trees drop most of their needles in the space of a year or two, regrowing them in such a way that the tree always has leaves.
So there you have some of this tree’s secrets for longevity. What about the secret of its name, you wonder? When will we reveal that? Well, the tree is named for the appearance of its cones. They’re all prickly and bristly because of spiny growths on the outside.
Good for you, Wondernose. You must have heard about the bristlecone pine somewhere!
Not all bristlecone pines are stunted and gnarled. It’s true that they grow slowly. That, in fact, also contributes to the tree’s long life. But if they grow in favorable areas with reasonably good soil, bristlecones can attain respectable heights of up to 70 feet (20 m).
Two species of bristlecone pine are known. The species that lives the longest is the Great Basin bristlecone. These are the ones that are known to reach 4,000 and more years. The one we looked at first was a Great Basin bristlecone that has been affectionately named Methuselah.
The other species is called simply Rocky Mountain bristlecone. These trees tend to reach the 2,000-year mark, which is still older than the Methuselah of the Bible, isn’t it?
