Tag: Trees

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Great Basin Bristlecone Pines Utah’s Mountain Sentinels

Bristlecone Pine
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Bristlecone Pine Grain
Compared to a Dime
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

Utah’s cold mountaintops, like its hottest deserts, are rather inhospitable to most plants. Although more precipitation falls at higher elevations, colder temperatures prevent much of the water from being used by plants, since most of it falls as snow in winter. High winds also inhibit growth and can contribute to frost or wind damage to plants. Any plants that grow here must be especially hardy.

The Great Basin bristlecone pine is a grand sentinel of our rocky, high mountain ridges. Its shorter needles are grouped in bundles of five, and grow densely at the end of the branches, creating a ‘bottlebrush’ or ‘foxtail’. However, the growth of the wood is the most interesting aspect of the Great Basin bristlecone pine. For a tree, each ring represents one year of growth. Because of the colder temperatures and shorter growing season, each growth ring of a bristlecone pine is particularly small, usually around 1/32th of an inch. The tight growth rings result in especially dense, resinous wood that is resistant to decay and insects.

At higher elevations, a bristlecone pine’s growth form becomes more twisted and contorted by the wind. Over time, much of the tree may die, and the living portion may simply be a strip of bark up the trunk and just a few branches.

These adaptations allow the Great Basin bristlecone pine to live an exceptionally long life despite such harsh conditions. It is common for a bristlecone pine to live for thousands of years, and the oldest recorded specimen was aged at approximately 5,000 years old. That means it germinated from seed a few hundred years before the first Egyptian pyramid was even built! Bristlecone pines can even remain standing for thousands of years after they die. Growth ring patterns can be compared between living and dead bristlecone pines to reveal a chronology of our climate for the past seven, eight, maybe ten thousand years!

To see bristlecone pines in Utah, hike the Bristlecone Pine Trail in Bryce Canyon National Park or the Ramparts Trail at Cedar Breaks National Monument. Be sure to take only photos, and not wood or cones. Bristlecone pines will be around a lot longer than we will, and they could use all the help they can get.

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:
Images: Courtesy & Copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.


Additional Reading:

Lanner, R.M. 2007. The Bristlecone Book: A Natural History of the World’s Oldest Trees. Mountain Press Publishing Company.

Cohen, M. P. 1998. A Garden Of Bristlecones: Tales Of Change In The Great Basin. University of Nevada Press.

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Autumn Colors

Autumn Colors: Fall Colors in Cache County Photo © 2006 Bridgerland Audubon Society
Fall Colors in Cache County
Photo © 2006 Bridgerland Audubon Society

In autumn, our days shorten noticeably and frosty dawns become the norm across most of Utah. Now leafy plants must be preparing for winter. Their summer of intense metabolic activities must gradually give way to winter’s dormancy. Photosynthesis and respiration are gradually shut down as nutrients and sugars are withdrawn from leaves, to be shunted to the stem and roots for storage.

The brilliant autumn yellows of our aspens, ash trees and cottonwoods, as well as the crimsons of our maples and sumacs, are all indicative of leafy plants frugality with their valuable nutrient stores. The foliar pigment phytochrome first registers the lengthening nights, initiating the cascade of physiological events that prepare a tree for the icy blasts of winter. Before discarding their leaves, deciduous trees and shrubs rescue and store what they can of sugars and nutrients found in their leaves.

The key photosynthetic green pigment, chlorophyll, and its attendant enzymes are all broken down, their components moved to storage for recycling next spring. Essential nutrients, such as nitrogen and phosphorus, are likewise extracted from foliage for later reuse. With chlorophyll gone, the other colorful leaf pigments are revealed in all their glory. These accessory pigments have been there all along, they just have been masked by the dominant green of chlorophyll.

These accessory pigments serve several functional purposes for the leaf. Some pigments protect the leaf from sunburn, some scavenge free radicals, but most capture energy from wavelengths of light missed by chlorophyll. The multi-hued spectrum of sunlight, as revealed by a prism or a rainbow, not only allows us to see splashy fall foliage colors, it is the reason for their existence.

For the plant physiologist and chemist, then, the palette of colorful leaf pigments have complex functional explanations. More mysterious psychological stirrings accompany the aching beauty of our autumn foliage, but it gives an undeniable tug at my heart. Standing before a blazing yellow stand of aspens, I smile to think that recycling can be so beautiful.

Credits:
Photo: Courtesy www.bridgerlandaudubon.org
Text: Bridgerland Audubon Society – Jim Cane, Linda Kervin

Additional Reading:
Utah Scenic Byways, https://www.utah.com/byways/fallcolorstour.htm
Utah Fall Colors, https://travel.utah.gov/Fallcolors.htm