Alaska, often associated with glaciers and vast tundra, is also home to extensive temperate rainforests. Specific coastal regions of the state receive the consistent moisture and moderate temperatures necessary for these unique forest ecosystems to thrive. This makes Alaska an important part of the global distribution of temperate rainforests.
Understanding Temperate Rainforests
Temperate rainforests are distinct forest biomes characterized by high annual precipitation and moderate temperatures. Unlike tropical rainforests, which are located near the equator and are much warmer, temperate rainforests are found in middle latitudes, typically between 40° and 60° in both hemispheres. These forests receive substantial rainfall, often ranging from 50 to 200 inches (140 to 500 cm) per year. Proximity to oceans and coastal mountains are common features, contributing to consistent moisture through heavy rain and fog. The climate maintains mild temperatures throughout the year, avoiding extreme heat or cold, which supports the growth of predominantly evergreen conifers.
Alaska’s Rainforest Regions
Alaska’s temperate rainforests are primarily located in its southeastern panhandle and extend northward along coastal areas. The Tongass National Forest, at nearly 17 million acres, stands as the largest national forest in the United States and the largest intact temperate rainforest in the world, covering approximately 90 percent of Southeast Alaska. Another significant area is the Chugach National Forest, which encompasses parts of Prince William Sound, the Kenai Peninsula, and the Copper River Delta, representing the northernmost extent of this ecosystem. These regions meet the criteria for temperate rainforests due to the influence of the Pacific Ocean and coastal mountains, causing high annual rainfall. Dominant tree species found here include towering Sitka spruce, western hemlock, western red cedar, Alaska yellow cedar, and mountain hemlock.
Life Within the Alaskan Rainforest
The temperate rainforests of Alaska support a diverse array of plant and animal life, adapted to the cool, damp conditions. Iconic wildlife such as brown bears and black bears thrive in these environments, often relying on abundant salmon runs. Bald eagles are particularly numerous, with more residing in this region than anywhere else in the world. Other animals include Sitka black-tailed deer, wolves, mountain goats, and marine mammals like sea lions, sea otters, and various whale species in the adjacent waters. The forest floor is characterized by lush undergrowth, a rich layer of mosses, ferns, and lichens, along with plants like skunk cabbage, devil’s club, and various berry bushes such as salmonberry.
The Significance of These Forests
Alaska’s temperate rainforests hold considerable ecological importance on a global scale. These forests function as significant carbon sinks, storing substantial amounts of carbon, often more per acre than even tropical rainforests. They provide essential habitat for a wide range of species, contributing to regional and global biodiversity. The extensive network of streams within these forests serves as a critical spawning ground for all five species of Pacific salmon, which are fundamental to the ecosystem. Beyond their ecological role, these forests are culturally significant, serving as ancestral homelands for Indigenous communities such as the Tlingit, Haida, and Tsimshian peoples.