How an underground fungal map of the world’s oldest, slowest-growing rainforest trees can boost the resilience of Earth’s long-term carbon sinks
Scientists demonstrate that a single 2,400-year-old tree protects hundreds, if not thousands, of underground fungal species.
image:
Evolutionary Biologist, Dr. Toby Kiers collects soil samples beneath one of the oldest trees on Earth, the alerce (Fitzroya cupressoides).
view moreCredit: Tomás Munita / SPUN
The temperate rainforests of the Chilean Coast Range are home to a spectacular array of life: iridescent blue lizards, tiny wild cats called kodkods, and curly vines of waxy red bellflowers. Towering over this biodiversity are endangered ancient conifers, called alerce (Fitzroya cupressoides), whose trunks can get as wide as shipping containers. These alerce forests show exceptionally low mortality and grow slowly—one tree lived more than 3,600 years.
New research published today in the journal Biodiversity and Conservation makes clear that these massive trees also shelter an enormous assortment of organisms belowground that have helped the forest, a massive carbon sink, survive and adapt over millennia.
One large individual—estimated to be over 2,400 years old—hosts more than twice the underground fungal diversity of smaller, younger trees of the same species. The bigger the alerce, the greater the variety of fungi that scientists found hidden in the soil, including hundreds of species that are likely new to science.
The discovery is important because these soil fungi, known as mycorrhizal fungi, help forests function. They funnel water and nutrients to trees through their root systems and assist plants in fighting stressors like drought and pathogens. The fungi also work as conduits for drawing carbon into soil. Globally, arbuscular mycorrhizal fungal communities—the type associated with alerce trees—move roughly one billion tons of carbon per year into Earth’s soils.
The scientists determined that protecting and conserving old trees will protect hundreds, if not thousands, of mycorrhizal and other fungal species that inhabit soils around these giants, each of which play a role we might not fully understand in keeping these forests healthy and resilient.
“Not all trees are the same and if you remove a millennial tree, the impact on all the other species is going to be bigger than if you remove a smaller one,” said the study’s co-lead author Dr. Camille Truong, a research scientist with the Royal Botanic Gardens Victoria and the University of Melbourne in Australia, and a mycorrhizal ecologist at the Society for the Protection of Underground Networks (SPUN).
Taking out one huge tree, in other words, can destroy an entire underground community of forest helpers that took thousands of years to assemble.
And “all that diversity means resilience,” said Truong’s co-lead author Dr. Adriana Corrales, Field Science Lead at SPUN.
The study grew out of an expedition to Alerce Costero National Park in Chile in 2022 by scientists with Universidad Santo Tomás, Universidad Austral de Chile, Universidad de La Frontera (Chile), Fungi Foundation and SPUN, a non-profit dedicated to mapping and conserving mycorrhizal fungal networks across the planet. SPUN was co-founded by evolutionary biologist Dr. Toby Kiers. Kiers was recently awarded the Tyler Prize (often called the ‘Nobel for the Environment’) for her work detailing the importance of underground fungal networks in unique ecosystems all over the world.
Alerce, sometimes called Patagonian cypress trees or lawal in Mapudungun, the language of the local Indigenous Mapuche people, are the second-longest-lived tree species on Earth after bristlecone pines. They are cousins to North America’s redwoods but live even longer. Alerce forests are found along the coasts of southern Chile and in the foothills of the Andes, but their range shrunk roughly in half over centuries as trees were cut for their durable light-weight wood or burned to make way for pasture. In fact, the oldest known individual, which lived 3,622 years, was regrettably felled in 1976.
And the trees are still threatened by land-use shifts, climate change, and major infrastructure projects. One proposed road would run just a few hundred meters from alerce forests, increasing the threat of fires, tourist pressure, and invasive species.
So, wanting to understand what was at risk and how best to protect remaining stands, Kiers and other researchers took soil samples from below 31 individual trees, ranging from saplings to the “Alerce Abuelo,” which is at least 2,400 years old, with a trunk that stretches more than 4.5 meters in diameter. They measured the size and biomass of each tree, later extracted DNA from the samples, and used genetic markers to identify fungi.
Truong then analyzed the soil data alongside the tree measurements and found that the fungal diversity in ground below the largest, oldest specimen was more than 2.25 times higher than in any other sample. Those soil samples also included more than 300 species of fungi unique to this tree.
This matters because losing soil fungal diversity “can trigger cascading, negative effects on multiple ecosystem functions,” the researchers wrote in their paper. These huge millennial trees serve as an “umbrella” that protects soil fungal diversity. Protecting that diversity can help keep other plants in the forest healthy.
Their paper is titled “Large-diameter trees disproportionately contribute to soil fungal diversity in a coniferous forest with one of oldest living trees on Earth.”
***
Link to additional photos and information here.
DOI 10.1007/s10531-026-03277-0
This work was supported by the Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), the Fondo de Financiamiento Centros de Investigación de Excelencia en Áreas Prioritarias (FONDAP), the Iniciativa Científica Milenio from the Agencia Nacional de Investigación y Desarrollo (ANID), and the Subvención a Instalación en la Academia from ANID. SPUN acknowledges the support of the Jeremy and Hannelore Grantham Environmental Trust, the Paul Allen Family Foundation, the Schmidt Family Foundation, Arcadia, and the Quadrature Climate Foundation. E.T.K. acknowledges support from NWO-VICI and NWO-Spinoza.
The Society for the Protection of Underground Networks (SPUN) is a science-based initiative launched in 2021 to map and advocate for the protection of the mycorrhizal communities that regulate Earth’s climate and ecosystems.
All authors: Camille Truong, Adriana Corrales, Bethan Manley, Michael E. Van Nuland, Justin D. Stewart, Rocío Urrutia-Jalabert, Roberto Godoy, Merlin Sheldrake, Giuliana Furci, E. Toby Kiers & César Marín
Journal
Biodiversity and Conservation
Method of Research
Data/statistical analysis
Subject of Research
Not applicable
Article Title
Large-diameter trees disproportionately contribute to soil fungal diversity in a coniferous forest with one of oldest living trees on Earth.
Article Publication Date
3-Mar-2026
No comments:
Post a Comment