Since last September, an unprecedented forest fire on Australia’s east coast has destroyed millions of hectares of forest and killed more than 1 billion animals,media reported. Fires have affected the vast and complex underground world, including organisms that are vital to ecological restoration: fungi. After the wildfires, the whole area looked less vibrant. Beneath the ashes, however, is a vast network of fungal lives.
A fungus called plexus root (AM), which forms a symbiotic relationship with most terrestrial plants in the world. This means that most plants grow and reproduce with AM fungi. Mycelium forms a fungal underground passage that delivers valuable nutrients to plants.
In addition, AM fungi can affect other aspects of plant ecosystems, such as seedling formation, plant growth, defense against herbivores, and competition among different plant species. At the same time, the variety and abundance of AM fungi determine the growth and diversity of plants.
If fungi are introduced into degraded and disturbed areas, plant diversity can increase by about 70%, promote the recovery of native plants, and inhibit weed invasion. At the same time, plant photosynthesis provides sugar for AM fungi. This means that without a plant host, the fungus will not survive.
Studies have shown that fungi that live near the surface of the soil are particularly prone to fire, and that they tend to be killed by higher soil temperatures when fires pass. Fungi below the surface are relatively well protected and can provide cell nuclei for recovery.
The 29 studies in 2017 concluded that the fire reduced the fungal species by about 28 percent. Given the severity of last year’s bushfires, we can expect many fungal communities beneath the surface to disappear.
Studies have shown that different types of AM fungi can support their plant mates in different ways. Some are good at providing nutrients, while others are more effective at protecting plants from disease and herbivores.
Of course, putting fungi back in fire-affected environments ensures faster and more comprehensive restoration of native vegetation, including the survival of endangered plants threatened by fire. But the focus is on what kind of fungus to introduce.