Deep underground, in the temperate rainforests of Chile’s Alers Costero National Park, lies an ancient conifer called ‘Gran Abuelo’ that has been guarding a hidden secret for thousands of years. A recent study published in the journal Biodiversity and Conservation revealed that the tree’s greatest value is hidden beneath the surface. Researchers examined soil samples taken from Gran Abuelo and found an unseen world of life within. By examining soil samples, they identified a community of more than 300 fungal species, many of which are unique to this ancient soil and not found anywhere else on Earth, forming a mycorrhizal network along Gran Abuelo. This mycorrhizal network not only provides Gran Abuelo with essential nutrients and water; It also serves as the foundation of the entire forest’s microbial ecosystem. All experts emphasize that if we lose one of these ancient trees, it can create a domino effect on the entire carbon cycle of the forest.
What exactly is ‘Gran Abuelo’
Gran Abuelo – or ‘Great Grandfather’ – is a giant Alers (Fitzroya cupressoides) tree located in Alers Costero National Park, Chile. Its height exceeds 60 feet and the diameter of the trunk exceeds 13 feet. Alers are native to the temperate rainforests of Patagonia and have existed for thousands of years. While some researchers are still debating its age, environmental scientist Jonathan Barichevich recently estimated through computer modeling and partial core sampling that Gran Abuelo is approximately 5500 years old. This would make it older than the bristlecone pine ‘Methuselah’ located in California and perhaps the oldest living individual tree on Earth.
Incredible discovery beneath Earth’s oldest tree
The incredible discovery wasn’t just how old the tree was; However, how much it supports underground life! As written in PhysOrg, researchers used a genetic technique called DNA sequencing to map the ‘mycorrhizal’ (fungal) network around the Gran Abuelo tree. They discovered that the soil beneath this ancient giant was 2.25 times more biodiverse than the soil beneath other more recently grown trees in the same forest; In fact, they discovered over 300 species of fungi in this ‘microbial metropolis’, many of which you can’t find anywhere else in the world.
How a fungus kept the world’s oldest tree alive
This discovery shows that the Gran Abuelo tree is not just a plant but serves as the center of a biological support system. Experts at the Royal Botanic Gardens at Kew say these fungi form a mutualistic relationship with the tree – the tree provides sugar (carbon) to the fungus through photosynthesis, while the fungus acts as an extension of the tree’s root system by reaching deep enough into the ground to provide the tree with phosphorus, nitrogen and water during periods of severe drought. Therefore, it is likely that it is this ancient network that has kept this tree alive against fire, climate change and centuries of environmental stress.
30,000 year timeline
Although the tree is thought to have existed for about 5,000 years, WWF also says the area served as an ‘Ice Age refuge’, allowing the soil biome to develop undisturbed for more than 30,000 years – long before Gran Abuelo took root; Thus, large underground networks were formed that store carbon dioxide within the Earth. If the ancient trees fall victim to climate change or human intervention, scientists warn that the loss of this 30,000-year-old carbon storage system would result in the release of vast amounts of greenhouse gases back into our atmosphere.