The Tongass National Forest in the US state of Alaska is a special place for conservation biologist Dominick DellaSala, even after decades of traveling the world exploring the soft tropical forests.
“The trees are big,” Del IslandSala, lead scientist at the Island Island Institute’s World Heritage project, told Mongabay. “It’s like being in a cathedral. “It’s an amazing place.”
yellow bark cedar (Callitropsis nootkatensis), hemlock mali (Tsuga mertensiana), and spruce Sitka (Picea sitchensis) are just some of the tree species that can grow for hundreds of years and anchor a rich and enduring landscape in Tongass. The August Sitka is the largest fir in the world and can climb one and a half meters (5 feet) per year during adolescence on its way to an altitude of about 100 m (330 ft).
Walking among the giants, bryophytes and lichens cover the forest floor and the ground is sponge underfoot, says DellaSala. Tonga National Forest covers 67,000 square miles (about 26,000 square miles) of southeastern Alaska. About 60% of it is forested, most of which is old growth. It also holds 12% of the world’s mild rainforest.
“You do not see this in most parts of the planet, let alone the gentle rainforest system,” DellaSala said. “It’s so unique on a global scale.”
DellaSala and his colleagues recently published a study that finds that Tongass forests hold about one-fifth of all carbon in the entire National Forest system of the United States. This is the equivalent of 1.5 times all greenhouse gas emissions from the US in 2019.
Their research came out on April 13 in the journal earth.
The relatively untouched Tongan has long been known for its charismatic North American wildlife management. Black bears (American bear), black-tailed deer Sitka (Odocolieus hemionus sitkensis), has long been a key food source for indigenous groups in the region and an endangered seabird called marble wall ()Brachyramphus marmoratus) everyone calls it the Tongan house.
Its rivers and streams also feed the living streams of six species of salmon and trout, attracting bald eagles (Haliaeetus leucocephalus) and brown bears (U. arctos) in unprecedented numbers. These tracks also support the productive fishing industry of the region.
Rivers and streams in Tonga feed the living streams of six species of salmon and trout, attracting bald eagles and brown bears in unprecedented numbers (photo: Chad Shmukler).
In 2006, a group of researchers estimated that carbon held in the Tongan forests accounted for 8% of all carbon in all forests found in the United States outside Alaska and Hawaii.
More than a decade later, DellaSala and colleagues from the Woodwell Climate Research Center in Falmouth, Massachusetts, decided to recalculate Tongass’ carbon content. They used tree cover data along with maps of productive forests, roadless areas and land use in national forests. They also researched historical timber harvest records to understand how heavy logging in the early 20th century may have affected carbon reserves. The result was this last document in earth.
They found that Tongass contains 2.7 billion metric tons of carbon, very close to what researchers had calculated in the 2006 study.
A map from the study shows the boundaries of the Tongan National Forest and its old and new mature forests (courtesy image of DellaSala et al. (2022)).
With this new study, DellaSala said they wanted to highlight how important Tongass is to the National Forest system, which is managed by the U.S. Department of Agriculture. The team analysis found that 20% of the system carbon is bound to Tongan rich soils, vegetation and especially trees. At the same time, it accounts for only 9% of the system’s land area.
Moreover, the density of carbon stored in the forest is superlative, reaching more than 800 metric tons per hectare at some points.
“There are few places in the world that can surpass what is in Tongass,” DellaSala said.
The Tongan National Forest holds some of the highest carbon densities found in any temperate tropical forest on Earth (courtesy image of DellaSala et al. (2022)).
But today, Tongass stands at the center of a long-running debate over whether its old forests should be protected from logging and roads. In 2001, then-President Bill Clinton signed into law the National Road Conservation Rule. Involved were large parts of the uninterrupted desert in Tongass. But since then, protecting order for off-road areas in Tongass has been constantly challenged in the courts. Republican presidents George W. Bush and Donald Trump used executive orders to undo these protections, arguing that forests are important for securing timber and the jobs in the industry that go along with it.
Despite the challenges, today more than 36,000 km2 (14,000 mi2) of Tongass have no roads. That adds up to 16% of the country’s roadless areas, DellaSala said, “which is huge”.
Last year, President Joe Biden’s administration signaled that it wanted to legislate off-road defense in Tongass so that they would not be removed, even if a less conservative president takes office.
“Restoring Tongass Roadless Protections supports the advancement of economic, ecological and cultural sustainability in Southeast Alaska in a way that is driven by local voices,” Agriculture Secretary Tom Vilsack said in a November 2021 statement.
In soft tropical forests like Tongass, DellaSala said, roads often mean more logging and possibly digging in previously untouched areas. Other studies show that building a road can damage the life of plants and animals, impede the flow and quality of water, and impair carbon sequestration up to a distance of 1 km (0.6 mi) on either side of the road.
The Biden administration’s efforts have angered supporters of the Alaskan logging industry.
“This is a disappointing decision that will affect not only timber, but a wide range of industries in Southeast Alaska – tourism, recreation, mining, energy development and transportation alike – so we will fight it,” Lisa Murkowski said. , a Republican senator who represents Alaska, said in a statement in November. “It is unnecessary, given the level of defenses that already exist for Tongass.”
But many conservatives and scientists disagree. Further aggravating industry supporters, the Biden administration is also considering a ban on commercial logging of Tonga’s old forests.
Fly fishing for pink salmon in a creek in Tongass National Forest (photo: Earl Harper).
This is important because previous research shows that these forests will not be affected as much by climate change as those inland, DellaSala said. In addition to safer carbon seals, they can also provide shelter for other species as temperatures rise.
“If you maintain the old growth, if you preserve the roadless areas,” DellaSala said, “you have the best chance at an adaptation strategy as the rest of the region deals with more shocks from climate impacts.”
Now, security groups are stepping up campaigns to see the end of roadless defense.
“This is the first step toward rescuing America’s last great tropical forest, which is vital and precious to Alaska’s indigenous tribes, fish and wildlife,” Niel Lawrence, director of Alaska, said in a statement in June. for the environmental protection NGO, the National Council for the Protection of Resources. 2021. “We are counting on Biden’s team to pursue and restore full defense in the Tongan wilderness. “It would show real leadership on the climate and heritage of our public lands.”
But DellaSala said the protection should not stop at just the old Tongass forests.
“We have places like the northeastern United States where forests are 100 years old and they are approaching old growth,” DellaSala said. These mature forests need to be preserved, he said. The study on Tongass shows the value of old forests as carbon storage that warms the climate and they support unique and complex ecosystems.
Plus, from DellaSala calculations, the U.S. Forest Service can meet its timber production targets by shifting the focus of logging to “young” growth stands that are typically between 55 and 65 years old and have sprouted. in previously cut areas.
“We found that there is more than enough young growth there,” he said. “There is no reason to cut the old growth.”
DellaSala said the mills will likely have to invest in new equipment that can handle smaller diameter logs and new growth. But the protections for both old and mature forests in the US would be an “example of how we can move to a more environmentally sustainable landscape trail while there is still time,” he added. “There are so few examples where we still have that opportunity worldwide.”
Walking a salmon stream in the Tongan National Forest (photo: Earl Harper).
For DellaSala, nowhere is this opportunity more apparent than in Tongass, the forest that has served as a touchstone throughout his career.
“I keep going back to Tongass because it’s just a great place to be saved,” he said. “It’s the essential jewel of the crown in the National Forest system.”
DellaSala, D., Brandt, P., Koopman, M., Leonard, J., Meisch, C., Herzog, P.,… Von Wehrden, H. (2018). Climate change can cause widespread change in the tropical coastal forests of the North American Pacific. Anthropocene Encyclopedia, 233-244. doi: 10.1016 / b978-0-12-809665-9.09367-8
DellaSala, DA, Gorelik, SR, & Walker, WS (2022). Tongass National Forest, Southeast Alaska, USA: A Natural Climate Solution of Global Importance. earth, 11(5), 717. doi: 10.3390 / land11050717
Ibisch, PL, Hoffmann, MT, Kreft, S., Pe’er, G., Kati, V., Biber-Freudenberger, L., … & Selva, N. (2016). A global map of roadless areas and their conservation status. science, 354(6318), 1423-1427. doi: 10.1126 / science.aaf7166
Leighty, WW, Hamburg, SP, & Caouette, J. (2006). Effects of management on carbon sequestration in forest biomass in Southeast Alaska. Ecosystems, 9(7), 1051-1065. doi: 10.1007 / s10021-005-0028-3
This story originally appeared in Mongabay and is part of Covering Climate Now, a global journalistic collaboration that strengthens coverage of climate history.