Wildfires have dramatic impacts on landscapes and forests. What may seem like only charred remains of an ecosystem, a microcosm of fungi can be seen in bloom.
In addition to destroying trees and property, fires can create new conditions for a forest ecosystem. Within weeks after a devastating fire is extinguished, the trunks and limbs of some trees become covered with a white, cream colored growth, eventually taking on an orange hue. The growth appears at the base and extends into the lower limbs and branches. This growth is caused by a fungus with unique adaptations that allow it to take advantage of the conditions left after a fire. The fungal growth may also be seen on branches lying on the ground, and will even sometimes extend onto the soil surface.
There are dozens of different fungi observed growing on trees worldwide following fires. According to a number of sources, these fungi have descriptive names, such as anthracophilous (coal loving), pyrophilous (fire-loving), or carbinicolous (coal inhabiting). They all have some attributes in common. Their spores, or reproductive structures, may be stimulated to grow by heat from the fire. The chemical nature of the bark changes following a fire, allowing a favorable nutritional environment for the growth of these organisms.
Not all trees in an area will be affected, but the growth may continue to spread to the effected trees for months after the fire. These pioneer fungi will serve as decomposers, providing nutrients back into the environment for the next wave of microbes and plants.
The after-fire fungi pose no threat to humans or animals, nor will they cause harm to the surviving trees in the area. They are one of the first steps in the recovery of the ecosystem toward a renewed, productive forest and should be viewed as evidence of the resilience of nature, even under the most catastrophic circumstances.