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(gentle solemn music) (birds chirping) - Last year, I heard about something I couldn't believe: a tree.
Explore Japan's Yakushima Island, home to ancient yakusugi cedars and unique ecosystems, revealing nature's resilience and biodiversity.
Key Takeaways
- Yakushima Island hosts some of Japan's oldest and largest yakusugi cedar trees, with ages possibly exceeding 3,000 years.
- The island's harsh climate and isolation have preserved a unique temperate rainforest ecosystem with many endemic species.
- Scientific dating of ancient trees is challenging due to rotted cores and variable growth rates.
- Japan's mountainous terrain and climate have helped preserve extensive forest cover despite population pressures.
- Protecting natural heritage and personal privacy are both important themes highlighted in the video.
Summary
- The video explores Yakushima Island, known for its ancient yakusugi trees, including one of Japan's largest and oldest cedars.
- Yakusugi trees are sugi cedars that have lived over 1,000 years, growing slowly due to harsh mountain conditions.
- The oldest tree was carbon-dated to around 2,170 years, but estimates suggest some trees may be over 3,000 years old.
- Yakushima's unique ecosystem includes diverse vegetation, endemic species, and a climate ranging from subtropical to subarctic.
- The island's isolation and extreme weather contribute to its rare biodiversity and the survival of old-growth forests.
- Japan's forests cover 70% of the country despite dense population and historical logging, thanks to mountainous terrain and climate.
- The video discusses scientific studies on tree growth rates and challenges in accurately dating ancient trees.
- Yakushima's altitudinal diversity compresses Japan's entire mainland ecosystem into a small island area.
- The video is sponsored by Incogni, a service that helps protect personal data by removing it from data brokers.
- The narrator reflects on the privilege of visiting such a unique natural environment and the importance of conservation.
Full Transcript — Download SRT & Markdown
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I am within the tree. The biggest tree in Japan, over five meters wide and allegedly the oldest in the entire world.
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I saw this claim everywhere: tourism guidebooks, newspapers, "The New York Times," the Journal of the "Japanese Society of Civil Engineers." The oldest trees on record are about 5,000 years old.
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So, what is this? It's a sugi, or Japanese cedar, growing high in the mountains of Yakushima, this small island off the south coast of Japan.
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This is what's called a yakusugi tree. If you are a sugi tree growing here on Yakushima Island, on your 1000th birthday, you get upgraded to a yakusugi tree.
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Big, old trees like this are abundant at the higher elevations up in the mountains here on Yakushima.
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For years, this island has occupied kind of a mythical spot in my imagination. In 1914, a famous botanist traveled here and described a bizarre landscape: mountains made of granite blocks heaped upon one another in vast confusion; old growth forests with cedars nearly 60 feet round;
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a forest floor made almost entirely of rotting plants; a striking diversity of ferns, mosses, lichens, fungi.
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He writes that nowhere else has he seen such a wealth of vegetation and describes this forest as the most interesting and remarkable in all of Japan.
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These trees have been prized throughout Japan for centuries, but this forest is beyond the reach of roads and loggers.
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Hauling these massive trees down the mountains would be near impossible. Instead, local residents cut fallen trees into shingles and carry them out by hand.
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The conditions up here suck: thin soil, cold winters, heavy rain, strong winds, typhoons. So these trees grow really slowly and live much longer than anywhere else in Japan.
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But could they really live for over 7,000 years? In 1984, the tree was carbon-dated to around 2,170 years old.
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But because it's so old, the inside has completely rotted away. So counting all of its rings or carbon-dating the oldest part is impossible.
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With other trees on the island living for over 3,000 years, 2,170 is almost certainly an undershot.
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The tree was first documented in 1966 by Iwakawa Teiji, who was in charge of the island's tourism.
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Around the same time, Kyushu University Professor Manabe Daikaku was studying tree rings, trying to understand how climate affects trees' growth rates.
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In 1968, he published this paper. He takes a sample of eight trees from Yakushima with known ages and divides them into two groups.
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Group A has an average growth rate of 169.73 millimeters per century, and group B has an average growth rate of 73.81 millimeters per century.
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He says that these values can be used to estimate the age of large trees.
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So, let's just divide the diameter of our record tree by this magic 73.81 millimeters per century.
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Because this tree is way up in the mountains and trees up here grow so slowly, to get this big, it has to be super old.
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That's basically the reasoning. A blog post from one of Manabe's students mentions that his eyesight was failing and he struggled to walk.
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So his conclusion wasn't based on visiting the tree or taking samples. It was based on the growth rates of other trees, which vary a lot.
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If we plug in Manabe's average for faster growing trees, group A, we get an estimate of 3,077 years, completely reasonable and still absolutely insane.
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(gentle solemn music) This is probably not the oldest tree in the world, but this forest is one of the oldest and one of the most unique.
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I love forests, and traveling here, I had so many questions. Japan is densely populated and has been for centuries.
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Just about every forest has been logged. And yet, 70% of the country is green.
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How did Japan's forests survive? And in a country that's prized big, high-quality cedars for centuries, how did the biggest and best survive this long?
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They almost didn't. (gentle solemn music) (insects chirping) 70% of Japan is covered with steep mountains.
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Along the Pacific Coast, the climate is nuts. Monsoon rains, typhoons, tropical storms. It's most traumatic on Yakushima.
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The island is small, just over 500 square kilometers, but its highest peak is nearly 2,000 meters above sea level.
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All that weather from the ocean smacks right into these mountains, making this the rainiest place in Japan and one of the rainiest in the world, 1,000 centimeters a year in the high mountains.
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Because of its steep terrain and heavy rain, Japan's soil is thin and unstable, but forests have managed to take hold here from tropical rainforests in the south to snowy boreal forests in the far north.
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In the middle, we find the Japanese temperate rainforest. Japan's forests are home to more than 5,000 plants.
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About a third of them are endemic species found only here: 60 endemic salamanders; unique endemic mammals like the Japanese macaque, tanuki, serow; and endemic sub-species of black bear; hundreds of tree species.
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Native temperate rainforests are mainly dominated by beech and sugi. Sugi is an endemic species.
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It's a member of the Cupressaceae family, the same family as giant sequoias and redwoods.
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Most of the world's oldest trees are members of this family. These trees appeared nearly 200 million years ago and once covered much of the planet.
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But today, most exist in isolated pockets. Yakushima's isolation from the mainland has created a unique ecosystem.
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Nearly 2,000 plants, about 100 of them endemic, 600 mosses. There are no beech trees here, so the forest is dominated by sugi and Yakushima's deer and macaques have evolved into distinct sub-species.
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The rainiest place in Japan, one of the rainiest places on the entire planet. And somehow, the forecast, almost the entire time we're here, is nice, clear blue skies.
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So taking advantage of the nice weather to get up into the alpine section of the island here, I'm approaching the highest peak.
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What makes Yakushima truly unique is its altitudinal diversity. Along the coast, you'll find subtropical vegetation and sea turtles.
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On the highest summits, just 10 kilometers inland, a subarctic climate similar to that of the far north of Japan.
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That's the climate and ecosystem diversity of all of mainland Japan compressed into one tiny island.
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(uplifting solemn music) Getting to go to places like this is such a ridiculous privilege.
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And the fact that it's even remotely possible to do that, like not just to go to Yakushima, but to spend months putting together this story is thanks to the sponsors who support these projects.
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This video is sponsored by Incogni and I am very excited to be working with them.
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Everything from spam text messages to full-on identity theft. Now, if you reach out to these data brokers and ask them to delete your information, they have to do it, but that's a time-consuming process and there are hundreds of them.
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It is intentionally difficult, so you won't do it. But that's where Incogni comes in.
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Again that's incogni.com/aidin A-I-D-I-N. Usually Aidin's not spelled like that, so maybe I should specify.
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Thank you again to Incogni for making this project possible and just help me to claw back my information from all the creeps.
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All right, let's get back in the woods. Around 2,500 years ago, rice was introduced to Japan.
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As it spread throughout the country and became the main food source, lowland forests were cleared to make room.
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The population grew, large cities developed, and ruling class emerged. In the seventh century, they began building massive castles, temples, and shrines, mainly around the biggest city, Kyoto.
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Rulers used a ton of lumber insisting on the biggest trees with the highest quality wood.
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They burned tons of charcoal to make metal tools and decorations. Small mountain villages made a living by harvesting forests to supply charcoal to the city.
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Once the forests surrounding the city were depleted, loggers began pushing deeper into the mountains and hauling timber from faraway forests, including the Kiso Valley, one of the largest forests in Japan.
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Wood was hauled in oxcarts or floated down rivers on rafts. Within a couple centuries, the city had overused its resources.
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Construction of large monuments slowed and the city declined. A few centuries later, population growth ramped up again and construction followed.
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Loggers in search of the best trees reached the edge of Honshu and began pushing into Kyushu.
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They found new ways to move big trees from the mountains to the cities. In 1180, Japan's biggest temple burned down, so the rulers sent an expedition to find trees good enough to rebuild it.
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They found a grove along the upper reaches of a mountain river in the far west of Honshu, about 400 kilometers away.
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They dredged out a valley to build a 20-mile road into the forest and cut down hundreds of large trees, keeping a few dozen of the highest quality.
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They built more than a hundred dams to raise the river's water level, floated the trees down downriver to the coast, towed them to the city behind ships, then used hundreds of oxen to pull them to the construction site.
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Thanks to Japan's mountainous terrain, logging remains slow and selective, and most forests had time to regenerate.
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In more remote mountains, old growth forests still survived. Toyotomi Hideyoshi took power in central Japan in 1582.
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He gradually expanded his role, and within a decade controlled all of Japan. He insisted on the finest timber and sent expeditions all across Japan to find it.
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One of his largest projects was the Hokoji Temple in Kyoto. He sent loggers on an expedition to find a perfect tree for the temple's central ridge pole.
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They found one at the foot of Mount Fuji, cut it down, rafted it down river to the coast, towed it behind ships to Osaka, then floated it up river to Kyoto.
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Months of effort for one tree. He sent one of his officers all the way to Yakushima to survey the island sugi trees.
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And some may have even been used for the temple. In 1608, the temple was damaged during an earthquake and the ridge pole had to be replaced.
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This time, the search took three years and sent loggers all the way to Southern Kyushu.
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Beneath Hideyoshi were daimyo, regional military leaders. They built cities and monuments of their own exhausting local forests.
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Some regions exported timber throughout Japan, gaining reputation for particularly high quality logs. Some daimyo made attempts to conserve their resources, setting aside exceptional stands or individual trees, including those near temples and shrines.
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Southern Kyushu was ruled by the Shimazu clan. In the early 1600s, the clan took control of Yakushima and ordered the islanders to pay taxes in timber, specifically shingles.
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The islanders considered both the high mountains and the yakusugi trees sacred. So they were reluctant to cut them down or even venture into the mountains and struggled to produce millions of shingles each year.
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Tomari Jochiku was a Buddhist monk and Confucian scholar from Yakushima. He trained at a temple on the island before moving to temples in Kyoto, Osaka, and Edo, today Tokyo.
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Living in Japan's biggest cities, he learned just how valuable big sugi trees were to the ruling class.
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In 1640, he worked as a priest for the Shimazu clan. He advised them on their resources and finances, including the potential of logging the yakusugi.
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Returning to Yakushima, Tomari told the islanders he had visited the mountains and received the God's permission to log the island's yakusugi.
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With the God's blessing, Yakushima's residents began cutting down the largest trees and shipping timber to the mainland.
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On the mainland, loggers began clear cutting entire stands. The biggest and best trees were used to build the rulers monuments and the leftovers were used to build houses for everyone else.
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Nonstop fires destroyed cities and reconstruction further exhausted timber supplies. By the late 1600s, entire forests had been wiped out, including the Kiso Valley.
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Good temper was so scarce that loggers were making their first expeditions into Hokkaido. Severe erosion and flooding were widespread, especially in the mountains surrounding Kyoto.
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Resource shortages grew more frequent and more severe. In 1657, a fire destroyed half of Edo and killed about a hundred thousand people.
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This time, the city struggled to find enough timber to rebuild. In 1665, the daimyo controlling the Kiso Valley did something unique.
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Recognizing that this deforestation was unsustainable, he cut logging in half. This is one of the earliest recorded attempts at sustainable forest management and it flopped.
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Like just a few years later, the daimyo needed some money and logging ramped back up.
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But in the following decades, other leaders took similar measures from small villages all the way up to the central government.
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They surveyed their resources and set aside forest reserves of all sizes, some protected certain species or even individual trees.
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They sent out forest rangers to catch timber thieves, report forest fires, and write reports for the government.
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It sounds a heck of a lot like the National Forest System in the States, just a couple centuries earlier.
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In 1724, the daimyo in the Kiso Valley once again cut logging by more than 60%, and it worked.
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The valley's forests largely grew back. This system was ahead of its time, but far from perfect.
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For the ruling class, forest preservation often just meant stealing land from small villages and hoarding it for themselves.
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The goal here was a consistent supply of timber to keep building, not protecting the environment, but it did have that side effect.
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A few leaders began taking things a step further. Not just preserving forests, but planting new ones.
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Governments began issuing forestry manuals, instructions, and best practices for foresters. I'm out for a little walk this morning in this village in the mountains right outside Kyoto that still uses a lot of these traditional Japanese forestry practices.
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After forests were logged, they were replanted as plantations, prioritizing the best species, particularly sugi.
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The manuals included detailed instructions on gathering seeds for replanting, drying the seeds, storing them, preparing them.
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Foresters built seed beds. Small blocks of soil or seeds were carefully watered, fertilized, and weeded.
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They built covers to protect them from snow, frost, and bright sunlight. After several years of this care, seedlings were carefully dug up, trimmed at the roots and replanted in the forest.
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In the regions thought to have the best trees, commercial nurseries emerged raising seedlings and shipping them all around Japan.
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Some foresters used cuttings instead of seeds. Small pieces clipped off the end of a branch and planted.
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Cuttings were taken from mother trees, the largest and highest quality. The idea was that the cuttings would inherit those good qualities.
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So they would pick out a particularly large healthy tree like this one and cut clippings from it and use those to replant the surrounding forest.
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So over the centuries, as this area has been logged, a lot of it has been replanted using clippings taken from this tree.
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If trees were too close together, small ones were removed too far apart and gaps were filled in with seedlings.
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A lot of foresters trimmed branches off of trees aiming to grow the straightest highest quality logs.
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Some would selectively leave some branches behind to create unique patterns in the wood grain.
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Like stick straight, they've been very carefully pruned as they're growing to keep them very even and straight.
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And then the branches are all trimmed right up to the very top, so they look almost like the neat trees in the "Lorax." Some regions became famous for specialized wood.
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All of this work had to be done at the right time and place. Sites were carefully selected for their soil, topography, weather, sunlight, and access.
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For sure, the most interesting looking are these daisugi trees that have been pruned such a way that they grow these branches straight up vertically out of the top.
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And these have been used to produce these very straight little poles very efficiently, and some of these trees have been maintained for hundreds of years.
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I think this one I'm looking at right now is about 400 years old. Super interesting to see these techniques in practice.
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It's so different from the forestry that I'm used to seeing back home, like very hands-on.
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By the mid 1800s, Japan had a stable supply of timber. Old growth forests had nearly disappeared.
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In their place, plantations of sugi were gradually spreading across the landscape. On Yakushima, between 50 and 70% of the yakusugi trees had been cut down.
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Loggers only wanted the straightest trees with the fewest knots. So most of the trees we see today survived thanks to their imperfections.
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In 1868, a new government took power in Japan, aiming to modernize industrialize and westernize.
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They reorganized Japan's government and its forests. Some were parceled out as private property, while others were absorbed by a new national forest system.
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The government surveyed forests, built forest roads and expanded plantations. 80% of Yakushima became part of the national forest.
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In 1914, American botanist E.H. Wilson visited Yakushima publishing writings and photographs that introduced it to the world.
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Japanese scientists published even more studies gradually revealing just how unique this place was. In 1922, the government designated about 10% of Yakushima's forest as a protected area for research.
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The same year they began building railways into the mountains to extract timber more efficiently.
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Between 1940 and 1970, three events changed everything for Japan's forests. First, World War II.
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Lots of timber needed to fuel the war efforts. Next, post-war recovery. More timber needed to rebuild much of the country.
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Finally, the post-war boom. Insane population growth, economic growth and construction requiring even more timber.
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New forest roads, industrial logging and aggressive conversion of native forests into plantations. Industrial logging and clear cuts reach Yakushima.
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Residents described barren mountains, forests cut down like a buzz cut. In the 1960s to meet the growing demand, Japan began importing timber from other countries.
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The more timber was imported, the less valuable domestic forests became. 1966, logging peaks in Japan and on Yakushima.
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The same year, Iwakawa records Japan's largest tree. This forest starts to get a lot more attention.
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A local conservation group is formed and begins campaigning to save the forest. A local high school instructor photographs clear cuts, shares the images door to door, and raises 7 million yen for a documentary.
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The film is screened on Yakushima and in Tokyo, Osaka and other large cities. A delegation from Japan's environmental agency visits Yakushima and urges immediate logging reform.
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A public debate is held on the future of the island's forests. 500 people attend.
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Researchers studying Yakushima's macaques worry that their habitat will disappear. A writer for Japan's largest newspaper describes logging in Yakushima as a desecration of history and an act of rebellion against nature.
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A flash flood washes away 20 homes and floods 200. The victims believe that flooding was worsened by clear cutting of the mountains above their village.
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They gather signatures and submit a petition to the forest service to stop logging. They're ignored, so they sue the national government.
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The local conservation group lobbies the national government. Making the case that Yakushima should be protected, not just for its record trees, but for its exceptional altitudinal diversity.
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1975, remote section of Yakushima is designated as a wilderness area. 1982, logging of ancient yakusugi trees is outlawed.
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1993, the island is designated as a UNESCO World Heritage site, the first in Japan.
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(light solemn music) And today, two thirds of Japan is forested. 40% of that is plantations, providing significantly less ecological value than native forests.
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Most beach forests have been replaced by faster growing sugi. While old growth forests are nearly non-existent, exceptionally large and old trees can still be found on the grounds of Buddhist temples and Shinto shrines.
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After the 1960s, domestic forestry became increasingly unprofitable and logging steadily declined. As more and more people moved from small villages to big cities, many plantation forests were abandoned.
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Others were harvested, but not replanted. Some villages managed to stay afloat by leaning into high quality wood and specialized products, often relying on centuries old methods to do so.
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The national forest staff shrank by 80%, and national forest management shifted to focus less on logging and more on recreation, research and conservation.
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Right around 2000, something changed. Thanks to both national and local efforts, Japan's domestic timber industry slowly started growing again.
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(gentle solemn music) Japan has some of the world's oldest forests and one of the oldest systems of organized forest management.
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But a lot has changed. Walking through perfectly, even plantations, it can feel like the old growth, the beach rainforests and the traditional forestry methods are old just things of the past.
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But there are still places where time just moves more slowly. (gentle uplifting solemn music) (gentle uplifting solemn music fades)
Topics:Yakushima Islandyakusugi cedarancient treesJapanese foreststemperate rainforestbiodiversitytree carbon datingendemic speciesnature conservationIncogni
