Contact: Dominick DellaSala (541/621-7223; dominick@geosinstitute.org)

Ashland, OR – Alaska’s Tongass rainforest may fair better in a changing climate than more southerly rainforest locales, according to a new study published in an online reference module “Earth Systems and Environmental Sciences” by Elsevier, a world-leading provider of scientific, technical and medical information products and services.

The release of the study coincides with President Barack Obama’s visit with the Arctic Council in Anchorage in advance of the United Nations climate talks. It follows a letter sent in April 2015 to the White House by hundreds of scientists calling on President Obama to speed the transition out of old-growth logging on the Tongass to preserve the rainforest’s unique climate and wildlife benefits.

Using global climate change models, an international team of scientists compared changes in temperature and precipitation anticipated near the end of the century across a vast coastal region of 1,800 miles from California’s coast redwoods to Alaska’s Tongass rainforest. They then related those changes to the climate conditions preferred by conifer species of commercial value and to temperate rainforest plant communities. Eleven scientists, including two from Germany, one each from Austria, Kenya, Canada, and Alaska, and five from the Pacific Northwest participated in the study.

According to Dominick A. DellaSala, chief scientist of the Geos Institute in Ashland, Oregon and lead scientist on the study, “For the first time, we can see how the Tongass uniquely possesses climate assets such as its pristine old-growth rainforests and a cool maritime climate that may provide rainforest species with a critical refuge from more extreme changes to rainforests anticipated to the south.”

In order to predict potential changes in rainforest species, scientists applied global climate change models from Alaska to California under the assumption of continued growth in global warming emissions. They analyzed 19 climatic variables and compared baseline climate conditions (1950–2000) to two future climate periods (2050s, 2080s).

Anticipated Changes to Rainforest Plant Communities (by the 2080s):

• Northerly locales are expected to experience greater precipitation and warming compared to drier conditions south.
• Southerly regions, where logging has greatly degraded forests, are more vulnerable to climate change and land disturbances than northerly locales where vast forested tracts remain and coastal climates provide refuge.
• Northern rainforest regions are expected to retain climate suitable for rainforest vegetation, while rainforest vegetation southward may lose preferred climate.
• Localized climate changes are likely to harm rainforest vegetation even in the north such as the Kenai Peninsula, portions of the Queen Charlotte and Haida Gwaii islands, and much of the mid and southern British Columbia coastline.
• The climate currently supporting subalpine (high-elevation) forest is expected to shift toward conditions more suitable for lower-elevation forests.

Anticipated Changes to Rainforest Conifers of Commercial Importance:

• Rainforest conifer species are expected to lose vital climate conditions and habitat southward and expand north and upward in elevation as glaciers recede; this will affect future forest management.
• Pacific silver fir, grand fir, Alaska yellow-cedar, and mountain hemlock may experience substantial climate-related losses. Prior studies have shown yellow-cedar declining due to reduced snow cover and late-winter freeze affecting the upper root zone.
• Western red cedar, Sitka spruce, and western hemlock may persist mainly in northern areas with minor losses in the south.
• Coast redwood is expected to lose nearly one-fourth of its climate by 2080 and already is experiencing declining fog levels needed to sustain redwood growth.

DellaSala added, “hundreds of scientists are asking President Obama to speed up the transition out of old-growth logging on the Tongass to save its unique climate, salmon, and wildlife assets. The Tongass should be featured among the nation’s first line of global warming defense and the Obama Administration’s international commitments to end global deforestation and forestall a pending climate change crisis.”

The Tongass National Forest is currently analyzing alternatives to amend the forest plan based on the Obama Administration’s interest in transitioning out of old-growth logging with a draft environmental impact statement anticipated this fall. The U.S. was among 157 signatories of the non-binding NY Forest Declaration, which pledged to slow global deforestation by 2020 and end it by 2030. The Tongass is the nation’s largest national forest.

Listen to the first of two 10-minute KINY radio inrterviews with Dominick DellaSala on Aug. 31, 2015.

Listen to the second of two 10-minute KINY radio interviews on Aug. 31, 2015.

Read the Sep. 2, 2015 news article from Juneau Daily News.