Forests

Bare tree trunks and small pine trees cover a hillside in front of another hill covered in a mature forest
Douglas-fir forests occur at lower elevations and are associated with the Lamar, Yellowstone, and Madison River drainages in Yellowstone National Park.

NPS / Diane Renkin

 

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 These forests may have been dominated by lodgepole pine at one time, but have been replaced by Engelmann spruce and subalpine fir in the absence of fire and presence of non-rhyolitic soil (a non-volcanic soil).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

 

Common Conifers

Higher-Elevation Species

Lodgepole Pine (Pinus contorta)

  • Most common tree in park, 80% of canopy
  • Needles in groups of twos
  • Up to 75 feet tall

Engelmann Spruce (Picea engelmannii)

  • Often along creeks, or wet areas
  • Sharp, square needles grow singly
  • Cones hang down and remain intact, with no bract between scales
  • Up to 100 feet tall

Subalpine Fir (Abies lasiocarpa)

  • Only true fir in the park
  • Blunt, flat needles
  • Cones grow upright, disintegrate on tree
  • Up to 100 feet tall

Limber Pine (Pinus flexilis)

  • Needles in groups of five
  • Young branches are flexible
  • Up to 75 feet tall
  • Often on calcium-rich soil

Whitebark Pine (Pinus albicaulis)

  • Grows above 7,000 feet
  • Needles in groups of five
  • Up to 75 feet tall

Lower-Elevation Species

Douglas-Fir (Pseudotsuga menziesii)

  • Resembles the fir and the hemlock, hence its generic name
  • Pseudotsuga, which means "false hemlock"
  • Cones hang down and remain intact, with three-pronged bract between scales
  • Up to 100 feet tall

Rocky Mountain Juniper (Juniperus scopulorum)

  • Needles scale-like
  • Cones are small and and fleshy
  • Up to 30 feet tall
 

Contact the Park

Mailing Address:

P.O. Box 168
Yellowstone National Park, WY 82190-0168

Phone:

(307) 344-7381
Recorded information. For road and weather information, please dial 307-344-2117.

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