Forests cover roughly 80% of the park and lodgepole pine comprises nearly all of that canopy. Lodgepole pine, Engelmann spruce, subalpine fir, whitebark pine, and limber pine are found at higher elevations.
Douglas-fir forests occur at lower elevations, especially in the northern portion of the park. The thick bark of Douglas-fir trees allows them to tolerate low-intensity fire. Some of the trees in these forests are several hundred years old and show fire scars from a succession of low intensity ground fires. In contrast, lodgepole pine trees have very thin bark and can be killed by ground fires.
At higher elevations, older forest is dominated by Engelmann spruce and subalpine fir, especially in areas that grow on andesite, a volcanic rock, such as the Absaroka Mountains. These forests may have been dominated by lodgepole pine at one time, but have been replaced by Engelmann spruce and subalpine fir in the absence of fire and presence of non-rhyolitic soil (a non-volcanic soil). Engelmann spruce and subalpine fir can also be common in the understory where the canopy is entirely composed of lodgepole pine.
In rhyolitic soils (another volcanic substrate), which are poor in nutrients needed by fir and spruce, lodgepole pine remains dominant. At higher elevations such as the Absaroka Mountains and the Washburn Range, whitebark pine becomes a significant component of the forest. In the upper subalpine zone, whitebark pine, Engelmann spruce, and subalpine fir often grow in small areas separated by subalpine meadows. Wind and dessication cause distorted forms known as krumholtz where most of the "tree" is protected below snow. Continue: Lodgepole Pine
Lodgepole Pine (Pinus contorta)
Engelmann Spruce (Picea engelmannii)
Subalpine Fir (Abies lasiocarpa)
Limber Pine (Pinus flexilis)
Whitebark Pine (Pinus albicaulis)
Douglas-Fir (Pseudotsuga menziesii)
Rocky Mountain Juniper (Juniperus scopulorum)