00:01Deep in the rainforests of southern Chile, a long-kept secret lies hidden.
00:09The first time I saw it, and every time since, it felt like stepping into a cathedral.
00:16Many people call it the Gran Abuelo, the great-grandfather.
00:21It's around 5,000 years old, one of the oldest trees on earth.
00:25And for some, it's like family.
00:30I want to live and die here. My roots are here.
00:35This is the story of trees that have outlived civilizations.
00:40And the people who are determined to keep them standing.
00:44But time is running out.
00:48We use the memory of the trees to improve our climate change projections.
00:54The memories stored in the trees' rings.
01:00Jonathan, now a renowned scientist, was born here in this forest.
01:10He grew up exploring it with his family, who dedicated their lives to protecting the Alerso trees.
01:15His grandfather, Anibal, and his mother, Nancy, were park rangers here.
01:24Then one day in 1972, Anibal came across an enormous tree, 28 meters tall, 4 meters wide.
01:33Or as Jonathan likes to put it, the tree decided to meet his grandfather.
01:37And that encounter shaped our family's story just as it shaped the story of the tree.
01:48It also marked the story of the tree.
01:50Grandfather, Anibal, passed away when Jonathan was just six years old.
01:59My grandfather taught me how to take my first steps in the forest.
02:12We'd go on long patrols through the park, and he'd teach me all of the names of the plants.
02:22I knew the names of the plants before I could read.
02:25The memories of my childhood with my family are what fuel my passion for science.
02:41Now, through science, Jonathan is trying to unlock the secrets of these ancient trees and protect them for the future.
02:48My mission now is to carry on and protect the legacy of my grandfather.
03:03The logging industry has already left scars in this region.
03:07Just kilometers from the national park, this native forest is gone.
03:11When you come up here and see the land like this, it hurts your soul.
03:19Especially knowing that this used to be a native forest and now it's just a forest plantation.
03:29Rocio Urrutia isn't against forestry. It's a key industry in Chile.
03:34But she warns that when it's overdone, it puts the ancient Alarse trees at serious risk.
03:39She did her masters at MIT, her PhD at Oxford, and came back home to study the trees she loves.
03:50Alerses are like encyclopedias of the past.
03:55Thanks to them, we now know the maximum temperatures for the last 5,680 years here in Chile's south.
04:03Over five and a half millennia, no other tree here can offer such insights.
04:12To scientists, they're a source of knowledge, helping us understand how the climate has changed and how to prepare for the future.
04:18Alerses trees are very sensitive to temperature.
04:22Their growth rings reveal the climate conditions of each year, right down to the exact spot where they grow.
04:29And the trees don't just tell us about the climate, they record history.
04:34We're scanning a sample with fire scars because Alerses let us pinpoint the dates of ancient fires.
04:46This scar here, for example, is from a fire in 1681.
04:50The oldest recorded fire we found was back in 1397.
04:59The scar might not look like much, but if you zoom in, you can clearly see it.
05:05And once you match the ring to the scar, you know the exact year the fire happened.
05:10While Rocio works in the lab decoding tree rings, Jonathan and his mother head out to check on their own research site.
05:22We call this a super site because we can track multiple processes all at the same time with this flux tower and the tiny micro dowel samples.
05:39There are fewer than a thousand flux towers like this around the world, and almost 80% are in North America and Europe.
05:50That means we're missing half the story, which makes Jonathan's work here all the more vital.
06:01The tower helps us measure how much carbon the ecosystem releases into the atmosphere,
06:07and how much carbon the forest absorbs as it grows.
06:15Forests absorb nearly a third of all fossil fuel emissions we produce each year.
06:20But we still don't know exactly how they're responding to a warming climate.
06:26Will forests capture more carbon, or less?
06:29And how much will they grow under these changing conditions?
06:33That's the part we try to answer with the measurements my mom takes.
06:39We see how much carbon absorbed through photosynthesis is actually stored in the tree.
06:44She takes these tiny samples, called micro dowels, during the growth season.
06:48We can use them to quantify exactly how much carbon ends up in the wood.
07:01But this kind of year-round data collection in the forest throws up all kinds of challenges.
07:06What happened to this page?
07:07The dog chewed that part, I can't see the date.
07:11For years, Nancy Enriquez has been trekking into the forest every week, gathering data that offers a rare window into the slow life cycle of these ancient trees.
07:29The Alersay forests are remote, the conditions are often unforgiving, and the work requires patience, precision and persistence.
07:47Then you went off to do your PhD in the UK, and you never came back.
08:00I'm here now.
08:02Yeah, okay.
08:05But it was hard for me when you left for college.
08:08I missed you so much.
08:10I was always worried, you being so far away.
08:18I've gotten used to it, but I'm still worried.
08:33The work you've done all these years, it's going to become the longest data record in the southern hemisphere.
08:38A lot of researchers are writing their theses using the samples you gave me.
08:45If it wasn't for you, none of this would be possible.
08:48And when we publish the scientific paper, you'll be a co-author, as you should be.
08:54Every trip you've made to the Alersays, I know you do it because you love it, but it's having an impact on the world you probably never imagined.
09:05You never told me that. I didn't know. I had no idea.
09:11Three generations have dedicated themselves to the well-being of this forest.
09:15And now, it may be facing the greatest threat in its long history.
09:29This used to be a logging road, built for the forestry industry to cut down trees.
09:47In the 1980s, the government shut it down and stopped issuing logging licenses in the area.
09:56Since then, the forest reclaimed the road. Hundreds, if not thousands, of Alersays began to grow here.
10:02Now, the government wants to take it back, to build a new highway.
10:14Oh, how terrible. Imagine what it would mean to have the road here again.
10:23Looking at the scars left by the old road, it's easy to imagine what damage a new one could bring.
10:36Someone has tried to cut this tree. Almost half of it has been cut through.
10:42Fortunately, as this other half remained, it managed to stay alive.
10:50And this is what we must avoid at all costs.
10:54Because these trees are a heritage of biodiversity.
10:59The old road was not only used by licensed logging companies, but also by illegal loggers.
11:08Alersay wood is highly prized because it's strong, straight and exceptionally durable.
11:17It became a symbol of tradition.
11:21Today, cutting down Alersay trees is completely illegal.
11:25But logging isn't the biggest threat the new road could bring.
11:31There's also the enormous risk of wildfires.
11:34More than 90% of the fires in this region occur by a road, so we can't add more risk.
11:41The Alersay is a protected species, and each individual tree is valuable.
11:49This isn't unique to Chile.
11:51Around the world, studies show a clear link between roads and the concentration of wildfires.
11:56In the Amazon, 57% of wildfires start within one kilometer of a road.
12:08According to one study, 69% of human-induced wildfires in the U.S. occur within 200 meters of a road.
12:15For endangered species like the Alersay, that are already surviving in small populations, large fires could be the end.
12:29The Alersay Costero National Park is located here.
12:33And this black line is where the government wants to build a road, connecting it to the existing roads, shown in green.
12:43Officials say it would provide a scenic route, connecting small towns, improving emergency access and boosting tourism.
12:50But locals say it's unnecessary, there's already a road that could be upgraded.
12:59One study found the new route would only save seven kilometers.
13:05So why push a new highway through a protected forest?
13:09Jonathan, Rocio and others suspect another reason.
13:13Timber.
13:15Just down the road in Corral lies the main export hub for Latin America's second largest pulp producer.
13:22A new road would carve deeper into untouched forests and lead straight to the port.
13:28When Deutsche Welle approached the Ministry of Transport and the Chilean presidency for an interview about the project, both declined.
13:36DW later sent written questions to the Chilean government about the necessity of the road, but received no reply.
13:46Roads shorten distances, they connect the world, but they also bring destruction.
13:51And we've seen this in all regions of the planet. Roads are a double-edged sword.
13:56In times like these, with a biodiversity crisis and climate crisis, we simply cannot build a highway through a national park.
14:13Especially not when there are alternatives that can connect the communities who want that.
14:19We want that.
14:24They made their concerns public.
14:30We joined forces, driven by a love for this species, these forests, and our national parks. We had to try.
14:38They decided to write a letter to science, one of the world's most respected scientific journals. Publishing there meant the global scientific community would take notice.
14:55This initiative was led by my colleague, Rosio Urrutia, who spent her career studying the Alerse forests.
15:01We wanted to make an impact that would reach the government, the decision makers, to show them that there's a scientific community concerned about protecting these forests. This isn't a whim.
15:15Scientists around the world joined in, raising their voices to protect the Alerse trees from extinction.
15:24Through this letter, we've stopped the project for now.
15:27I felt incredibly happy. Not for myself, but for the planet, for nature. Seeing that all our work paid off, seeing the project suspended, it felt like a gift.
15:44It showed that even the hardest battles can be won.
15:47They can inspire us as students to continue to work, and be a friend of mine.
16:09They all inspire us to continue the work, as students.
16:11They inspire us as students to continue our careers and to defend these unique places.
16:25To meet brilliant people who also have a political conscience and want to teach us, that's incredibly
16:32lucky.
16:35Their work and dedication are making a real difference.
16:48The road project is on hold.
16:59But global temperatures are continuing to rise.
17:03And that makes forest conservation more urgent than ever.
17:15The road project is on hold.
17:28The road project is on hold.
Comments