In the temperate rainforest of Chile’s Alerce Costero National Park, deep underground, there is an ancient conifer called the Gran Abuelo that has been protecting a hidden secret for thousands of years.
A recent study published in the Journal of Biodiversity and Conservation revealed that a tree’s greatest value lies in what is hidden beneath the surface. Researchers examined soil samples taken from Gran Abuelo and found an undiscovered world of life within. By examining soil samples, they identified a community of more than 300 species of fungi, many of which are unique to these ancient soils and found nowhere else on Earth, and which form a fungal network with the gran abuelo.
This mycorrhizal network not only provides essential nutrients and water to Gran Abuelo; It also serves as the foundation of the microbial ecosystem of the entire forest. All experts stress that if we lose one of these ancient trees, it could create a domino effect throughout the entire carbon cycle in the forest.
What exactly is “Gran Abuelo”?
Gran Abuelo – or “Great Grandfather” – is a massive alerce tree (Fitzroya cuprisoides) located in the Alerce Costero National Park in Chile.
It stands over 60 feet tall and has a trunk diameter of over 13 feet. Alerces are native to the temperate rainforests of Patagonia and have been around for thousands of years. While some researchers still debate its age, ecologist Jonathan Baricevic recently estimated through computer modeling and partial core sampling that Gran Abuelo is about 5,500 years old. This would make it older than Methuselah, the bristlecone pine in California, and perhaps the oldest living individual tree on Earth.
The amazing discovery under the oldest tree on Earth
The surprising finding was not the age of this tree; However, it was the amount of life it supported underground! As written in PhysOrg, the researchers used a genetic technique, called DNA sequencing, to map the “mycorrhizal” (fungal) networks 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 newly grown trees in the same forest; In fact, they’ve discovered more than 300 species of fungi in this “microbial city,” many of which you can’t find anywhere else in the world.
How fungi kept the world’s oldest tree alive
This discovery demonstrates that the Gran Abuelo tree is not just a plant, but serves as the center of a biological support system. Experts from the Royal Botanic Gardens at Kew say that these fungi create a mutualistic relationship with the tree – the tree provides the fungi with sugar (carbon) through photosynthesis, while the fungus acts as an extension of the tree’s root system by reaching into the ground deep enough to provide phosphorus, nitrogen and water to the tree during periods of severe drought. It is therefore likely that this ancient network is what has kept this tree alive against fires, climate change and centuries of environmental pressures.
30 thousand year timeline
Although the tree is thought to have been around for about 5,000 years, WWF also states that the area served as an “Ice Age refuge,” allowing soil biomes to develop undisturbed for more than 30,000 years – long before the Gran Abuelo itself took root; Thus creating large underground networks that store carbon dioxide deep in the ground. If ancient trees fall victim to climate change or human intervention, scientists warn that the resulting loss of the 30,000-year-old carbon storage system will release massive amounts of greenhouse gases back into our atmosphere.
