Rainforests are characterized by the high amount of rain they receive, rather than by air temperature or latitude. There are two types of rainforests: temperate and tropical. The Tongass National Forest in southeast Alaska harbors part of Earth’s largest remaining temperate rainforest, the Pacific coastal temperate rainforest, which stretches 2,500 miles from northern California up to Kodiak Island in south-central Alaska.
Allison Bidlack, director of the Alaska Coastal Rainforest Center in Juneau, took time to speak with us about changes impacting the rainforest in southeastern Alaska. One of the most visible changes is the dying off of the iconic yellow cedar tree in the Tongass, a direct impact of global climate change. Yellow cedars are characterized by shallow root systems. As temperatures in the region increase, particularly winter temperatures, the area is receiving less snowpack, which normally helps insulate the soil and the tree roots. Late spring freezes can freeze the roots of the yellow cedar if there is not enough insulation from snow, killing the tree. There are currently over 500,000 acres of dead or dying yellow cedars found in Tongass National Forest.
There are more subtle changes happening in the environment in southeast Alaska as well. For example, changes in hydrology along with rising temperatures are impacting the timing of salmon returns and the chemistry of the soil. Alaska is experiencing the highest rate of glacial volume loss in the world. And the ocean is becoming more acidic. We are moving into an era that is unfamiliar to us as a civilization as a result of all these changes. We encourage you to read more about the ecology of the Alaska rainforest and how these systems are all connected in this brochure.
To learn more about southeast Alaska, check out these other video stories from Juneau: