Mount Rainier Ecology
Mount Rainier National Park is a towering landmark roughly 60 miles southeast of Seattle, Washington. Ascending to 14,410 feet above sea level, this active stratovolcano in the Cascade Range is home to over 20 glaciers, five major rivers, and unique, elevation-dependent ecosystems.
Park Life Zones
Mount Rainier National Park is divided into three major life zones, or ecosystems found at different elevations, throughout the Park. These life zones are home to plants and animals that are specially adapted to each elevation range. From lowest to highest elevation, the three zones are classified as the forest zone, subalpine zone, and alpine zones.
The Forest Zone
The forest life zone covers nearly 60% of the park, covering elevations ranging from 1,700 to 6,000 feet. It is further divided into low-elevation forest, mid-elevation forest, and high elevation forest. Across this zone, forest ages range from young (<100 year-old) trees to old-growth (>1,000 year-old) stands.
Low-elevation (1,700-2,700 feet in elevation) forests are dominated by western red cedar, Douglas fir, and western hemlock trees. In mid-elevation forests (2,700 to 4,000-6,000 feet, depending on slope orientation), Alaska yellow cedar, noble fir, western white pine, and Pacific silver fir trees are the most abundant trees. High-elevation forests (>4,500 feet) include subalpine fir, Alaskan yellow cedar, and mountain hemlock trees.
The Subalpine Zone
The subalpine life zone covers roughly 23% of the park spanning elevations from 5,000 to 7,000 feet and categorized into five broad vegetation groups. At these higher elevations, trees become less dense and vegetation becomes a mosaic of herbaceous meadows and clumped tree communities. Here, the location of plant communities and the extent of tree cover is limited by the depth and duration of seasonal snowpack.
Heather/bell-heather/huckleberry communities are classified by areas of dense, low shrubs. On the west side of the park, heather and huckleberry dominate the landscape.
Sitka valerian/showy sedge communities host tall, dense stands of perennial wildflowers. They are found in areas where physical disturbances, particularly avalanches, hinder the growth of shrubs. Many wildflower species, such as lupine, Sitka valerian, mountain daisy, glacier lily, avalanche lily, American bistort, pasqueflower, paintbrush, and Gray’s, are found here.
Black alpine sedge communities that consist of dense mats of black sedge are present in areas that experience late-season snow and a short growing season. Wildflowers such as alpine willow-herb, partridge foot, and alpine aster are present. This community may also include showy sedge and mountain hairgrass.
Low herbaceous communities are dominated by mosses and are found in areas of unstable soil or disturbances. Here, vegetation grows in clumps. Species found here include alpine buckwheat, saxifrage, pussytoes, partridge foot, hawkweed, and black sedge.
Green fescue communities consist of grassy meadows of mountain bunchgrass, located on the eastern side of the park. Because of the rain shadow effect, the eastern side of the park receives less snow and rainfall than the region west of the Olympic Mountains. Species here include fan-lead cinquefoil, lupine, and cascade aster.
The Alpine Zone
The highest-elevation life zone, the alpine zone, extends upward from the tree line to the mountains’ summits. Approximately 50% of the alpine zone is covered by permanent snow and ice. The remainder of the zone is covered by alpine vegetation, which is divided into four broad vegetation types: fell fields, talus slopes, snow beds, and heather communities. Fell fields experience intermediate growing seasons and are classified by shallow slopes covered with small rocks and dispersed groups of flowering plants such as sedges, asters, and penstemons. Talus slopes, steep areas of loose, unconsolidated rock fragments, are classified by small, well-spaced out groups of plants, and experience the longest growing season. These areas are the first to be free of snow. Snow beds are categorized by well-spaced groups of plants that experience the shortest growing season. This area may not be free of snow every year. Heather communities experience intermediate growing seasons and are the oldest known communities within the park boundaries. Some heather communities have persisted in the park for more than 10,000 years.
Animals
Reptiles
In 1991 and 1992, herpetofaunal surveys were conducted in Mount Rainier National Park's aquatic habitats. The common garter snake, wandering garter snake, rubber boa, northwestern garter snake, and northern alligator lizard are among the reptile species documented in the Park. Garter snakes tend to be common in the summer within the Park.
Amphibians
Amphibians are highly sensitive to changes in environmental conditions, so they are a reliable indicator of the health of an ecosystem. Frog species in the Park include the Cascade, coastal tailed, and Pacific chorus. Several salamander species, including Cope’s giant, coastal giant, long-toed, Van Dyke’s, western red-backed, northwestern, ensatinas, and larch mountain salamanders are present. In addition to frogs and salamanders, western toads and rough-skinned newts also inhabit the Park.
Birds
Common bird species in the Park include eagles, hawks, owls, bluebirds, hummingbirds, sparrows, and warblers. Marbled murrelets, bald eagles, and peregrine falcons, all listed as protected under the Endangered Species Act (ESA), are frequently spotted in Mount Rainier. In addition, the northern goshawk, Harlequin duck, and willow flycatcher, listed as sensitive species, have been observed in the Park. Northern spotted owls, listed as endangered under the ESA, are the only endangered bird species that permanently inhabits the Park.
Some bird species dwell in the Park year-round, but most species live there only during specific seasons. At the lowest elevations (<3,500 feet), northern spotted owls and marbled murrelets are among the bird species found. At elevations between 3,500 to 5,000 feet, bird species in this area depend on the availability of food sources and the timing of breeding season. Many bird species are found in the subalpine elevation zone, from 5,000 to 6,500 feet, especially during the summer season.
Fishes
Since 1999, Mount Rainier National Park staff have been taking inventory of the fish communities within the park. The most common fish species in the Park belong to the Salmonidae family, which includes salmon, char, whitefish, and trout. From 1915 to 1972, the Park's water bodies were stocked with non-native fishes and now, many of these fishes, such as Eastern Brook Trout, and kokanee salmon, have breeding populations in Mount Rainier National Park.
Mammals
Bats, which are mostly nocturnal, are the only mammalian group able to fly, and several species inhabit Mount Rainier National Park. Big brown bats are most active just before dawn and at dusk and they primarily eat beetles. They roost under loose tree bark, in tree cavities, and in human-made structures, such as buildings. The hoary bat, one of the largest bat species found in this park with a wingspan of approximately 16 inches, can be found around meadows and lakes after dusk while hunting for beetles, moths, and flies. Townsend’s big-eared bats are also found in the park and their ears can be more than one-third the length of their body size. Other bat species that call Mount Rainier National Park home include the little brown bat, long-legged bat, yuma bat, and silver-haired bat.
Several other mammal species are found in Mount Rainier National Park including black bears, coyotes, bobcats, mountain lions, Cascade red foxes, fishers, raccoons, minks, striped skunks, and short and long-tailed weasels. In 2020, camera traps captured images of the first wolverines seen in the Park in 100 years. Wolverines are the largest land-dwelling member of the weasel family, and are rare in the United States, with an estimated population of between 300 and 1,000 individuals in the contiguous United States. Other mammals seen in the Park include black-tailed deer, mountain goat, elk, shrew mole, coast mole, snowshoe hare, pika, and rodents, such as mountain beavers, chipmunks, northern flying squirrel, marmots, mice, voles, northern pocket gophers, and porcupines.
Plants and Other Species
Mount Rainier is known for its wildflowers. Although wildflowers are found in both the forest and subalpine regions, they tend to thrive in the subalpine zone due to their limited growing season and need to bloom and reproduce in a short amount of time. In low elevation forests, the most common types of range from white to yellow/orange to pink/red/purple. The subalpine regions yield white, yellow/orange, blue/purple, and red/pink wildflowers.
Lichen is abundant in this area, with over 500 different species within Mount Rainier National Park. There are three general growth forms of lichen; foliose, fruticose, and crustose forms. Lichen is important for our ecosystems, as it has a direct relationships with air quality and pollution, and it serves as a bioindicator for scientists to document how anthropogenic, or human-induced, pollution affects specific parts of the environment. Monitoring trends in lichen growth can also assist researchers towards a better understanding of changes in climate over time.
Ecological Disturbances
Disturbances, such as wildfire, play an important role in ensuring ecosystem health in Mount Rainier National Park by promoting vegetation species diversity. They help remove established forest habitat, which allows new plant communities to take root. Disturbances vary in size and frequency based on the ecosystem in question. While large fires are relatively infrequent in the park due to the abundance of precipitation, they are large-scale disturbances that reshape the plant communities within the Park. Avalanches and lahars, volcanic mudflows, are considered small- to medium-scale disturbances. Small-scale disturbances also include wind damage, insects, and disease, which can affect local community dynamics. Humans can also act as sources of disturbance, especially in subalpine meadows, affecting the vegetation in the area.
Research
Ecological restoration efforts at Mount Rainier and within the Pacific Northwest region are currently underway with the USGS and National Park Service. A few of the current research projects are listed:
- USGS Ecologists are testing a hypothesis to determine if the effect of experimentally removing barred owls from the pacific northwest area would result in improved population trends of the northern spotted owl. They are analyzing site-occupancy dynamics, reproduction, survival, recruitment, and population change over a four year period to see how the controlled environments behave in comparison to the natural environment and to ultimately figure out the effort and costs associated with long-term population control to ensure positive influence of the spotted owls.
- Mercury bioaccumulation and contamination is heavily researched and monitored by the USGS and partner scientists. This issue affects the ecosystem and human health on a global scale and could lead to unfavorable environmental problems if not mitigated. The ecological factors linked to mercury toxicity can be traced to the bioaccumulation of methylmercury, which is mercury in its organic form and extremely toxic. There are several currently active research projects dealing with mercury bioaccumulation and cycling in progress with the USGS across the country. In relation to the Pacific Northwest specifically, the Contaminant Ecology Research Program (CERP) at the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, Oregon is experimenting with the influence of landscape and food web factors on bioaccumulation and researching the effect mercury has on vertebrate physiology, behavior and reproduction. These researchers have also begun a collaborative initiative to relate landscape and climate influences on mercury distribution in the western states.
- The USGS is currently working alongside the National Park Service, universities and Tribal scientists to implement mammalian ecological restoration and wildlife management both within and around National Parks to ensure ecological integrity and authenticity for future generations to experience the outdoors as our previous generations had done. This work includes monitoring invasive plant and animal species within park boundaries, adapting to changing environmental conditions and ecosystem processes, and restoring wildlife populations and communities.
The USGS, in correspondence with both public and private agencies, is continuously researching and working towards proper monitoring of geological and ecological processes to understand evolving environmental systems and to better prepare for future system disruptions.