The Forestry Corner
January 28, 2021
We all have seen aspen, growing on a hillside, with their lighter shade of green than the surrounding pine. Perhaps in autumn when patches of gold show up on a hillside and we say, “The aspen are changing color.” But have you noticed an aspen forest when you walk into it?
I remember years back, when I had been spending my days working in a pine forest. Day after day dark green forest. Then one afternoon, the forest glowed. The summer sunlight was filtering through the green aspen leaves making the whole area have a beautiful emerald glow. I had entered a mature aspen stand.
In autumn, traveling a forest trail with my family through an archway of golden aspens. It was so beautiful, and a little sad when it ended.
During the fading gray light of dusk. I was wading alone, through knee deep snow and having an eerie feeling walking through the ghostly white trunks of the leafless aspen as the winter moon rose.
Fresh buds, uncurling with the growth of spring time. One day the trees are bare, the next leafed out in fresh bright green foliage with the promise of warmth after a long cold winter.
Aspen is considered the most widely distributed tree in the United States and North America. The tree’s range is from northern Alaska, east to Newfoundland, and south to Virginia and Ohio. In the western states and provinces, the range extends from Alaska all the way to northern Mexico, following the higher elevation of mountain ranges and plateaus.
Aspen grow near sea level in the northern part of their range and higher elevations through the southern extent of their range, where they grow at over 12,000 feet elevation in Mexico. All the states in the mountain west have some aspen groves, with the largest groves being in west central Colorado and east central Utah. Here in our Black Hills, we live in an island of its range where it is the second most abundant tree species.
Aspen trees are more selective than ponderosa as to where they will grow in the Black Hills. Adequate moisture, sunshine and relatively cool temperatures created by elevation and exposure dictate where our native aspen grow and thrive.
Aspen seed can be abundant and it has a high germination capability. But the light seed has a short window of viability, during which it needs to be placed in the perfect seed bed. The proper soil moisture and temperature are critical for seedling development.
The more common form of regeneration is vegetative; otherwise known as cloning. From a young age, aspen trees can produce new sprouts (clones) from off their roots. Whenever the aspen tree is disturbed, such as from wildlife browsing, cutting or wildfire, it stimulates the sprouting of new stems.
These clones can cover a large area. Just because a group of aspen trees are growing together does not mean they are of one clone. Clones can grow among each other, expressing their own characteristics. Have you ever seen a patch of orange aspen among the gold leaves in fall?
A very interesting part of aspen clones can be their age. The individual aspen tree may live as long as 200 years. But the clone can be much older, reaching thousands of years old; making aspen clones one of the oldest and largest living organisms on earth. (Look up the Pando Aspen Grove in Utah).
The current state champion aspen tree is right here in Crook County. Perhaps while you are walking through the emerald glow of the aspen leaves, you will find it.
This periodic column is jointly offered by the Wyoming State Forestry Division and the Wyoming Tree Farm Committee, a landowner advocacy group, associated with the American Forest Foundation. The mission of this column is to provide interesting information about trees and forests.
Submitted by Ed Mignery, Wyoming Tree Farm Committee, Chairman and Jeremy Dedic, Wyoming State Forestry Division,
Assistant District Forester, District #1