Steamboat Springs U.S. Forest Service interpreter Renee Brousseau has one bit of advice to offer when she leads the tree identification group through downtown Steamboat Springs every other Thursday evening, attempting to educate her class about the evergreen trees that surround the city.
"Just reach out to the tree and shake its hand," she said to a class in July, while gabbing a small branch of a spruce tree and feeling its needles.
In the higher elevations of the Routt National Forest, there are primarily three types of evergreen trees mixed in with the aspen stands: lodgepole pine, Englemann spruce and subalpine fir. Ponderosa pines, Colorado blue spruce and Douglas fir trees also are present in the forest, but not on such a wide scale.
Brousseau explained the trees may all look the same from a distance, but the best way to find out what you are looking at is to feel the needles.
Spruce needles are square and sharp. Fir trees, on the other hand, have needles that are flat on each side and soft and friendly to the touch.
Both fir and spruce tree needles are individually connected to a branch. However, pine trees can be identified because their needles are usually in a packet of two that connect to the branch in the same place.
The catch phrases to remember the three rules are: square, sharp, spruce; flat, friendly, fir; and pines are in packets.
In all, the U.S. Forest Service estimates aspens cover one-third of the forest, lodgepole pines cover another third and the rest is a mix of spruce and fir trees.
Evergreen and aspen trees can read like a history book.
The mix of trees in the higher elevations can show a history of the fires in the forest, U.S. Forest Service supervisory forester Gary Roper said.
After a forest fire, lodgepole pine and aspen usually are the first trees to grow in the area, both thriving in direct sunlight.
Some cones on a pine tree open only to let their seeds out in extremely hot conditions, like in a fire, encouraging the tree to multiply after a blaze clears an area, Roper said.
Not surprisingly, pine trees also burn easier than other species of evergreen trees, further securing its dependence on fire disturbances to multiply.
Therefore, stands of pines and aspen trees are usually evidence a fire has gone through the area. At the Steamboat Ski Area, for example, which is famous for its aspen stands to ski through, a fire is thought to have burned there in the 1800s, giving way so the aspen trees could multiply, Roper said.
While aspen and pine trees like the sun, spruce and fir trees thrive in the shade. Typically, after a disturbance, the aspen and pine trees grow first, creating a canopy. Then spruce and fir trees begin growing in the shade, Roper said.
"That's why you can find so many fir trees in aspen stands," he said.
Stands of old-growth spruce trees, which can live more than 300 years, are a good indication the area hasn't burned in a long while.
Inversely to the pine tree's relationship with fire, spruce and fir trees are more resistant to blazes. A fire that wipes out a spruce and fir forest tends to be more intense, hotter and larger, Roper said.
While evergreen trees and aspens rule higher elevations in Routt County, narrowleaf cottonwoods rule the valley floors near waterways. Box elders and dogwood trees join the large, wide-diameter trees draping over waterways in the Yampa Valley; they all prove to be important elements in a river's health, riverkeeper Bill Chase said.
"They are really the basis of the food chain," he said.
Leaves from the trees are the diet of most of the insects near rivers.
In turn, those insects are the diet of the aquatic life.
The trees also play a large role in keeping a friendly, cool environment for fish.
"Research on trout shows that they do best in shaded areas," Chase said.
They also do better in deeper water, which cottonwoods around rivers help maintain by stabilizing banks with root systems. Without the roots, a river's energy erodes its banks, eventually making the river wider and more shallow.
When that happens, the sun can warm up the water, making it uncomfortable and possibly lethal for the fish, Chase said.
"It's all a working system, and if something is missing, it has a problem," Chase said. "And if everything is working, it's beautiful."