To some people, they are a curiosity, to others – a delicacy. But for plants and ecosystems, fungi are a necessity. In many ways, fungi are the unseen heroes of gardens, forests, and our environment as a whole. Without fungi, the world would be a much more barren and boring place. We wouldn’t have many of the foods and medicines that we have come to rely on. Without fungi, there would be no bread, no antibiotics, and more importantly, no beer! In this article, we’ll look at the role of fungi in nutrient cycling, the relationships that fungi form with plants, and the many ways we can encourage healthy fungi in our home environment.
The Underground Kingdom
Historically, fungi were classified as plants. Mushrooms, which are the fruiting body of fungi, sprout from the ground, so this seems like a natural assumption. Today, we know that fungi are actually more closely related to animals, and they are now classified as a separate kingdom of life. You’ve probably heard the terms “flora and fauna” used to describe the entirety of life in a given place. But considering the huge contribution that fungi make to our ecosystems, a more accurate description of life would be “flora, fauna, and fungi.”
For mushroom-producing fungi, the vast majority of their biomass exists below the ground, in the form of a branching network of thread-like filaments called mycelium. Though their subterranean nature has made these fungi somewhat mysterious, scientific research continues to improve our understanding of these complex organisms.
You’ve probably heard of the 3 R’s: Reduce, Reuse, and Recycle. Most of us try to recycle and compost when we can, and in Canada we’ve made a lot of progress in the past few decades. In contrast, fungi have been master composters and recyclers for over a billion years! Through their role as decomposers, they form a critical part of marine, freshwater, and terrestrial ecosystems.
As they break down organic material to feed themselves, fungi return energy and nutrients back into the environment, which contributes to the important process of nutrient cycling. Nitrogen is one of the most important nutrients for encouraging plant growth. Most of the time, it is locked up in proteins, making it inaccessible. Luckily for plants, fungi have the powerful ability to metabolize these proteins. In the process, nitrogen is released into the soil, allowing a plant’s roots to readily absorb it. This process is one of the critical ways that fungi benefit plants and the ecosystem they live within.
Mutual Connections with Plants
One fascinating aspect of fungi is the connection they form with the roots of plants. This relationship is known as a mycorrhiza. The term mycorrhiza comes from Greek and literally means “fungus root.” In these relationships, the roots of a plant become intertwined with the mycelium of a fungi. The plant provides the fungi with sugars produced through photosynthesis, while fungi deliver water and vital nutrients to the plant. This process occurs in the majority of plant species, and allows both the plant and fungus to thrive in a symbiotic exchange. Often, specific groups of fungi will associate with specific plants. For example, evergreen trees like Douglas fir have their own associated fungi. In fact, one study found that an individual Scots pine tree had formed mycorrhizae with 15 different species of fungus! Mycorrhizae are also found in important food crops, like wheat, contributing to our food security.
What’s even more incredible is that mycorrhizal networks can connect different plants over large distances, allowing for resource-sharing. Researchers at UBC have demonstrated that carbon can be extracted from a healthier tree species and transported to a less healthy one if both are colonized by the same mycorrhizal fungi. Similar studies have looked at the lifestyle of the snow plant, Sarcodes sanguinea. This intriguing species is able to thrive in the mountains of Oregon despite being incapable of creating sugars through photosynthesis. As it turns out, the snow plant is able to absorb sugars from its symbiotic fungi. Theses sugars are “stolen” from neighboring red fir trees through their mutual fungal connection. In the end, the secret to the snow plant’s success is its interaction with fungi. Some local Mayne Island plants that employ the same thieving strategy include ghost pipe and coralroot orchid.
Additionally, fungi are a valuable food source for a variety of animals. For example, small mammals like mice and squirrels are known to feed on mushrooms, providing them with a source of vital minerals. These small animals are a part of the food web, providing birds and larger mammals with sustenance. Large mammals, like caribou, also rely on fungi to supplement their diet. In the winter, caribou primarily eat lichen, which is a form of fungi that lives symbiotically with algae. Overall, fungi are important partners to their plant neighbours, but they also provide benefits to animals. Next, we’ll look at the benefits they provide to our gardens.
Encouraging Fungi in Your Garden
There are many ways we can promote the growth of fungi and increase the benefits that they provide. Here are a few ideas:
- Mulch: incorporate organic compost into your garden, providing fungi with a good food source.
- Leave decomposing wood: leave dead trees and branches to rot when they fall; this organic matter encourages fungal growth. Additionally, dead wood is great habitat for native amphibians like long-toed salamanders and the endangered red-legged frog.
- Avoid soil compaction: when possible, avoid using heavy machinery on your property. This practice harms the ability of roots and mycelia to travel through the soil.
- Increase biodiversity: plant a variety of native species to encourage the growth and development of their associated fungi.
The next time you see a fallen tree in the forest, take a moment to appreciate fungi for the way they keep nutrients flowing through an ecosystem. Let’s try to look at garden waste and rotting debris from a different perspective. This organic material provides food and nutrients to fungi which, through their mycelia, break down this material to provide essential nutrients for our plants. By recognizing the value of fungi, we can help create richer, healthier gardens and ecosystems.