Northern Pacific Coastal Forests
The Northern Pacific Coastal Forests represent one of the largest temperate rainforests in the world, stretching along the western coast of North America from southeastern Alaska down to northern California. This unique biome is characterized by its high rainfall and diverse vegetation, including key conifers such as Sitka spruce and western red cedar, as well as deciduous trees like birch and cottonwood. The topography of the Pacific Coast Mountains, combined with the climatic influence of the northwestern Pacific Ocean, plays a significant role in shaping these forests, which host ancient old-growth trees due to the absence of frequent fires.
Historically, human economic activities such as logging have severely impacted these forests, leading to the loss of much of the old-growth habitat and endangering species like the marbled murrelet. Despite conservation efforts, clear-cutting remains a threat, particularly in areas like the Tongass National Forest, which has faced significant logging activity over the years. The ecosystem is also intricately linked to the marine environment, with salmon playing a crucial role in both ecological balance and human sustenance in the region.
Various stakeholders, including governments, native populations, and conservationists, continue to grapple with the challenges posed by forestry practices, climate change, and habitat degradation. As the future of the Northern Pacific Coastal Forests remains uncertain, ongoing discussions focus on the need for protective measures and adaptive stewardship to preserve this vital biome.
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Subject Terms
Northern Pacific Coastal Forests
- Category: Forest Biomes.
- Geographic Location: Western region of North America.
- Summary: Over the past 100 years, one of the world’s largest temperate rainforests and its old growth have been widely lost because of human economic activities.
The Pacific Northern Coastal Forest biome forms a band of vegetation from Alaska to northern California. The far northern parts include the Tongass National Forest in southeastern Alaska and also cover south-central Alaska as well as British Columbia in Canada, and areas of coastal Washington and Oregon. Despite wide over-logging, all these regions still make for major conservation hot spots.
The existence of this biome is linked with the coastal mountain range topography of the Pacific Coast Mountains—which include, running northwest to southeast, the Kenai Mountains, the Chugach Range, the St. Elias Mountains, the Coast Mountains, and the Cascade Range—as well as with the climate regime of the northwestern Pacific Ocean. Likely, the glaciation period and its succession and climate shaped most of this unique forest biome. The vegetation is defined by its huge rainfall, and it classifies broadly as a temperate rainforest. Because of the high amount of rain and subsequent lack of frequent fires, trees can get very old and form unique old-growth vegetation.
Sitka spruce, yellow and western red cedar, mountain and western hemlock feature as the key conifers here—the dominant flora community. Broadleaf trees appear in the form of birch, alders, and cottonwood; these deciduous types are mainly restricted to riverine zones and damp bottomlands.
Salmon also make for a distinct habitat feature, with the biome’s thousands of streams connecting to the Pacific, making an exceptionally good base for their anadromous life cycle. Salmon have run here for thousands, and likely millions, of years, largely undisturbed. This formerly superabundant food source allowed human habitations to take root and grow in the region, but salmon now are widely endangered throughout. Large predators, including a variety of bears and the bald eagle, are at least partly dependent upon salmon in their diet.
Forestry Impacts
Forestry in this region became a dominant industry in the latter 1800s, with practices such as clearcutting becoming a threat to many species of reptiles, amphibians, mammals, and birds. For example, while the endangered marbled murrelet seabird species still breeds in this habitat, its sharp decline has been linked to the loss of more than 80 percent of old-growth forest in the region due to commercial logging operations. Lawsuits about the listing and protection of marbled murrelets through the U. S. Endangered Species Act and various civil disobedience campaigns over several decades speak to the recognized unique value of this habitat.
Despite changes in logging laws, clear-cutting has remained a threat in this region. Large-scale clear cutting of old-growth forest is still permitted in Tongass. It is the last national forest to still allow this practice. From 1950 to 2024 over 1 million acres of trees in the Tongass have been cleared, accounting for over half of the forest's old large-growth trees. In 2015, the logging industry cleared over 6,000 acres. A law meant to protect forests from logging, called the Roadless Rule, was enacted in 2001, however, the Trump administration exempted the Tongass from this rule in 2020, allowing logging there to continue. In 2023, the Biden administration reinstated the roadless rule protections to the Tongass.
In addition to the terrestrial impacts, this ecosystem is also inherently linked to the coastal marine environment. Many nutrients from fertilizer and pesticide use have saturated some streams and complicated their outflow absorption into the aquatic biomes. Rampant construction of dams has altered sedimentation patterns and decimated salmon runs, increasing the human impacts on native species. Aquaculture, or farming of salmon and other fishes, is yet another factor in an environmental scene that has changed permanently and thus challenges those who would conserve it to devise more adaptive stewardship techniques, as well as cooperation with fisheries, the timber industry, and other constituent groups.
Real estate development, increasing tourism activities, new invasive species, and altered marine chemistry each deliver new inputs and potentially increasing stress to this rich habitat area. Various entities—state and national governments, citizens, native populations, and scientists—continue to address the need for protected areas, species support, and changes in public policy that will help sustain this biome.
Global warming effects on the Northern Pacific Coastal Forests biome are difficult to predict. Some research has shown, for example, that past periods of lower temperatures and lower rainfall have actually led to the establishment and expansion of various tree types on some coastal mountain ranges in this region. The future effect of a higher temperature/higher rainfall regime is unknown. Also unclear is how pervasive the inland influence of altered patterns and interaction among such offshore factors as the North Pacific West Wind Drift current, the California Current, coastal upwellings, and many impacts from Asia.
Bibliography
Durbin, Kathie. Tree Huggers: Victory, Defeat & Renewal in the Northwest Ancient Forest Campaign. Mountaineers Books, 1998.
Huettmann, Falk. "From Europe to North America into the World and Atmosphere: A Short Review of Global Footprints and Their Impacts and Predictions." The Environmentalist, vol. 10, no. 7, 2011, pp. 89-96.
Lackey, Robert T., et al., editors. Salmon 2100: The Future of Wild Pacific Salmon. American Fisheries Society, 2006.
Ruth, Maria Mudd. Rare Bird: Pursuing the Mystery of the Marbled Murrelet. Rodale Books, 2005.
"Special Areas; Roadless Area Conservation; National Forest System Lands in Alaska." Federal Register, 27 Jan. 2023, www.federalregister.gov/documents/2023/01/27/2023-01483/special-areas-roadless-area-conservation-national-forest-system-lands-in-alaska. Accessed 30 Oct. 2024.
Steves, David. "Marbled Murrelet Gets Endangered Status in Oregon as Climate Change Threatens Its Survival." Oregon Public Broadcasting, 10 July 2021, www.opb.org/article/2021/07/10/marbled-murrelet-endangered-status-oregon-climate-change-threat/. Accessed 30 Oct. 2024.
Wolf, Edward C., et al. The Rain Forests of Home: An Atlas of People and Place. Ecotrust Publications, 1995.