On the tallest mountain in South Korea lives a small population of fir trees nicknamed the Christmas Tree Forest. The evergreen conifer looks much like the classic fir that many people worldwide bring into their homes at this time of year—and in fact it’s the species Koreans buy for a live holiday tree.
Abies koreana occurs only in South Korea, growing mostly in the southern part of the country. The largest population is on Jeju Island, approximately 60 miles offshore in the Korea Strait. The fir is distinctive in a variety of ways: It’s petite, as firs go, only reaching 30 to 60 feet—compared to over 300 feet for other fir species. Also, it grows slowly in its alpine-like environment—taking almost 30 years to reach maturity—and produces cones when it’s only three feet tall.
“Most firs have much longer lifespans and live in much colder climates,” says Kim Chan-soo, a former analyst at the Korea Forest Research Institute. And then there’s the color: “The color is very unique. It’s never completely green because the underside of the needle is white. It feels almost blue somehow.”
Christmas trees have only in the past decade or so become a phenomenon in South Korea, where about 30 percent of the population is Christian. Not only has the holiday grown in popularity over the years—Christmas Day was made a national holiday shortly after the end of World War II—COVID19 restrictions have increased Koreans’ enthusiasm for indoor plants and holiday decorating. During the summer, the government handed out “pet plants” to ease mental health strains caused by the isolation required to combat the virus. This season, more people are opting to decorate indoor trees to create holiday cheer.
According to one survey by job portal service Albacall, 48.6 percent of nearly 1,000 respondents planned to decorate a Christmas tree at home. Living Christmas trees, once rare finds in Korea, have become widely purchasable online as nurseries cultivate the Korean species.
But there’s trouble in the Christmas Tree Forest. While holiday demand for the trees is on the rise, that’s not hurting them, experts say. It’s climate change that’s killing off Abies koreana: Almost half of the trees in the wild have vanished in the past 20 years.
Losing the battle
Although the fir can be found in small numbers on a handful of mountains in southern regions of the main Korean peninsula, the main population is on Jeju’s Hallasan Mountain, an active volcano with 1,800 different kinds of plants. The Korean name for the trees, gusang-namu, comes from the combination of the Jeju words kusal (sea urchin) and nang (tree)—locals believed the tree’s pointy needles resembled that of a sea urchin’s spines.
Kim Jin, a field researcher at the National Institute of Forest Science, grew up on the northeastern coast of Jeju and has hiked the mountain over 3,000 times in his 30-year career.
“People on the island don’t think of Hallasan as just a mountain the way mainlanders might,” he says. “To us, Hallasan is Jeju and Jeju is Hallasan.”
Instead of an idyllic scene of lush, snow-clad greenery that might be expected on a mountain almost 6,000 feet high, visitors to Jeju’s Christmas Tree Forest these days step into the aftermath of a battle the forest clearly lost: hundreds of uprooted trees, fallen trunks stripped of all color, and withered branches stretched out toward the sky.
“People stop to take selfies here because the trees look so strange,” and most don’t know what kind of trees they are or why they’re dead, says Kim Jin.
In 2012, the trees were classified by the IUCN’s Red List as endangered. The fir is often called an indicator species for climate change, given its sensitivity to environmental shifts, especially heat. Also, unlike most trees, which have vertical roots, these have roots that grow horizontally above the ground, making them more susceptible to being toppled by typhoons.
Jeju has seen a number of intense typhoons in the past decade, tropical cyclones that have wiped out both people and plants. Approximately 9 percent of the trees died between 2009 and 2014; some of this is attributed to Typhoon Bolaven (2012) which also killed 19 people. During the summer of 2020, Typhoon Bavi (Category 3), Typhoon Maysak (Category 4), and Typhoon Haishen (Category 2) blew through the island in a 10-day period, killing two people, causing power outages, and destroying more trees, as well as buildings.
Just a few months prior to the back-to-back typhoons, research published in the Proceedings of the National Academy of Sciences provided evidence that categories 3, 4, and 5 storms are on the rise because of global warming.
Where the species lives plays a large role in why scientists consider it to be so important. Since the weather on Jeju Island is temperate at certain elevations, the firs are more likely to be stressed by heat. As a result, their response to heat stress is easier to study than that of other fir trees like the Norway spruce, which typically grows in colder regions across northern, central, and eastern Europe.
“These friends need snow on the ground from December to May,” says Kim Jin. In previous years, the snow would slowly melt, keeping the soil moist and protected against drought. Now, winter keeps getting shorter on Hallasan, and so the dry spells last increasingly longer. “Last year, it didn’t even snow on Hallasan at all!” he says.
Other factors that have been cited as causes for the trees’ overall decline include warmer weather year around and erosion, as winds and droughts literally change the ground under the firs’ feet. There is also a question of why trees at higher elevations are dying at higher rates. On Hallasan Mountain, the trees at 5,000 feet have an 18 percent higher survival rate than those at 5,550 feet, where half of the trees have died.
Kim Eun-sook, climate change analyst at the National Institute of Forest Science, says all of those things fall under the greater umbrella of global warming.
“As it is, subalpine plants must endure in less-than-optimal climates with severe cold, harsh winds, and snow. If you expand the temperature of the trees’ environment on top of that, it becomes even harder for them to grow normally,” she says. Even a small change in temperature is a lot to trees already dealing with many other factors, such as winds from more frequent typhoons.
Kim Eun-sook points out that this species is adapted to the cold, but the rapid pace of climate change means the trees can’t cope with the heat. And without the trees, she fears that the entire Hallasan ecosystem could collapse.
As the trees go, so goes the forest
According to the National Institute of Forest Science, which measured the abundance and density of all woody plants on Hallasan, Abies koreana supports its surrounding community more than any other tree. The species has a symbiotic relationship with dozens of plants, such as the medicinal herb Astragalus membranaceus, used in traditional medicine, and the rare Korean crowberry. They would go extinct on Jeju without the fir, experts say.
“A lot of the work we are doing here at the Forest Institute is trying to come up with ways to prevent the disappearance of plant species like the Abies koreana from their natural habitats,” Kim Eun-sook says.
Since the ‘90s, thousands of Abies koreana trees have been planted on mountains across South Korea, with little success. Harsh winds and temperature differences between the tree nurseries and the wild outdoors have made for low survival rates, particularly on Hallasan. But Kim Jin remains hopeful that the species will be saved.
The Korea Forest Service has been diversifying the genetic makeup of the trees’ seeds. It planted 1,350 Abies koreana on Geumwon Mountain in the southeastern region of the mainland last year, and so far, 99 percent have survived. The Jeju provincial government five years ago began planting 5,000 trees every year between February to April, but it will take another five to 10 years to see how well those trees take root and hold up against heavy winds.
Kim Jin believes the increased demand for Christmas trees in South Korea helps bring more attention to the plight of Abies koreana.
“I hope that a better understanding of the trees can help spread awareness about the importance of saving them,” he says. “I don’t know if the species will die out in a hundred year’s time, but I think they will survive my lifetime.”