The Ponderosa Pine

It’s Trivia Tuesday, Travelers – at least, according to pretty much every social media site around. So, let’s learn a little trivia about a very widespread tree found in many units of the National Park System.

How many of you have visited Bryce Canyon or Zion national parks in Utah, or Black Canyon of the Gunnison National Park in Colorado, or Wind Cave National Park in South Dakota, or Yosemite National Park in California, or Scotts Bluff National Monument in Nebraska, placed your nose next to the bark of a ponderosa pine tree, and taken a good long whiff? Did you smell vanilla, butterscotch, cookies, cinnamon, or even coconut?

Every time I hear the word “ponderosa,” I think of that 1960s Western series Bonanza. But that’s not why this particular pine tree was named ponderosa pine (Pinus ponderosa). Rather, the name comes from the ponderous (heavy) wood produced by this pine, which is the major lumber tree in the Southwest. This tree is so widespread, not only will you find it here in the (mainly) western/southwestern portions of the U.S., but also in Mexico and western Canada.

Ponderosa pines are long-lived, reaching 500 or more years in age. They are tall trees growing up to 200 feet (61 meters) with a trunk diameter of 3-4 feet (0.9 – 1.2 meters). You can tell them apart from other pine species by their thick, rust-red/yellow bark that looks sort of like jigsaw puzzle pieces. Trees younger than 150 years will have black, rather than rust-red bark. The trees with black bark are nicknamed blackjacks. Younger trees have pointy tops, middle-aged trees have more rounded tops, and the old trees sport flat tops.

The needles grow 4-10 inches (10-25 centimeters) in length, three to a group. Their dark, purplish seeds are winged, sort of like maple tree seeds. Blown by the wind, these seeds can reach heights of 1,000 feet (305 meters) before falling to the ground to either germinate or be eaten by birds, small rodents, or humans. Native Americans ate the seeds raw or made into a bread. They also utilized the tree’s pitch as an adhesive and waterproofing agent, and the bark for firewood, medicine, and building material.

Ponderosa pine trees are an important species for tree ring dating (dendrochronology) and studying climate change.

According to Park Staff:

In wet years, trees grow wide rings. In dry years, the rings are narrow. Reading tree ring widths from the roof beams of cliff dwellings and other Indian ruins has allowed archaeologists to precisely date their construction.

Ponderosa pine tree bark contains chemical compounds called terpenes. These complex chemicals act as sort of a tree immune system, repelling insect pests and parasites. Believe it or not, birds stopping to snack on the bugs found on a ponderosa pine tree’s bark can actually alter the flavor profile of the tree’s terpenes, according to an article by University of Colorado Boulder.

As to why ponderosa pines exude such a pleasant aroma, scientists are not totally certain, but do theorize that perhaps these terpenes are the aromatic catalysts, most noticeable on a warm, sunny day when the sun heats up the tree bark.

Another theory as to this pine’s wonderful smell is that vanillin, a compound that gives vanilla its characteristic scent, is a common degradation product of phenolic compounds found in lignin, a substance present within wood.

Why do some people smell butterscotch, while others smell vanilla or cookies (I smelled cookies) when they sniff a ponderosa pine tree? This might be due to individual differences in smell perception or variations in the trees' chemical composition (perhaps due to those birds snacking on the insects within the bark). 

So, the next time you are out hiking and happen to spy a ponderosa pine or two, stick your nose right up against this tree’s bark and take a good, long sniff.