Meet the Largest Living Organism, aka the Humongous Fungus

The humongous fungus isn't just a single mushroom you'd pick up in a forest; it's an enormous underground network of mycelium, the vegetative part of a fungus that looks like a web of tiny threads. These mycelial threads spread across the forest floor by digesting enzymes from decaying wood and soil.

They're all part of a single genetic individual, rather than a host of different organisms. While you might see mushrooms popping up on the surface (these are the fruiting bodies of the fungus), the majority of the fungus exists beneath the soil, spreading its roots in search of new nutrients.

The humongous fungus grows throughout Malheur National Forest in Oregon's Blue Mountains. It spans over 2,385 acres — an area roughly the size of 1,665 football fields. Scientists estimate the organism to be around 8,000 years old. It stretches across multiple national forests in Oregon.

In addition to Malheur National Forest, a similar fungus takes up plenty of space Fishlake National Forest in Utah.

In fact, these fungal colonies sometimes overlap with quaking aspen trees like Populus tremuloides, whose root systems often connect underground. This network of tree roots and fungal mycelium forms an intricate web beneath the soil, and both species rely on the other for nutrients.

Like other fungi, the humongous fungus relies on its root system, or mycelium, to spread. The mycelium grows through the soil, breaking down organic matter like dead trees and plant material. Through the process of decomposition, the fungus gets the nutrients it needs to grow.

But unlike trees, which grow upward into the sky, the humongous fungus grows outward, reaching astonishing lengths through the forest floor. Over the centuries, its roots have spread across vast stretches of the forest floor, tapping into a network of nutrients and continually expanding its territory.

If you look closely, you might spot new growth on the forest surface, which is when the fungus produces honey mushrooms. These mushrooms release spores into the air, which can help the fungus spread even further and reach new areas.

While the humongous fungus may be the largest organism in the world, it's not the only giant in the natural world. Other organisms like the Sequoiadendron giganteum (the world's largest tree) and certain massive mammals also hold impressive records for size.

However, what sets the humongous fungus apart is its ability to exist as a single organism across such a vast area.

Still, the humongous fungus shares some characteristics with other large organisms, such as Pando, a clonal colony of quaking aspen in Utah. Both Pando and the humongous fungus are single genetic individuals that spread through their underground root systems.

The humongous fungus is more than just a record-breaking organism; it's also a vital part of the forest ecosystem.

As a decomposer, it helps break down wood and other organic material, returning valuable nutrients to the soil and making them available for other species. In doing so, it supports the entire forest community, from the large trees that tower above to the small creatures that rely on the forest floor for food.

The USDA Forest Service has conducted extensive research on the humongous fungus, recognizing its importance in maintaining the health of forest ecosystems. By studying the fungus, scientists can learn more about how these organisms contribute to soil health and support the growth of trees and other plants.

In fact, without the work of decomposers like the humongous fungus, forest ecosystems would struggle to thrive.

Additionally, the fungus has become an important subject of study at institutions like Utah State University, where scientists investigate how fungi contribute to forestry and forest management practices.

Understanding these organisms can help scientists and foresters develop better practices for maintaining healthy forests, improving biodiversity and even managing issues like cattle grazing and fires.

As we learn more about the humongous fungus, we gain valuable insights into the complexities of nature. Scientists continue to study this massive organism, not just to understand its size and growth patterns, but also to learn how it interacts with other species, such as mule deer, trees and other plants.

This research is crucial for preserving the ecosystems that rely on fungi like the humongous fungus to maintain balance.

By studying the fungus and its ability to grow and spread, scientists are gaining a deeper understanding of how fungi contribute to forest health, as well as the role they play in the landscape. They're also exploring how fungi can improve the management of forests and combat the challenges posed by fire suppression and other environmental threats.