Burning forest benefits manys species

The benefits of a prescribed forest burning start as soon as the fire is lit. For instance, the beetle Melanophila acuminata, with its distinctive black and soot-colored appearance, often arrives immediately. It can detect the smell of smoke from several kilometers away and flies toward the fire to find a mate with which it reproduces in the embers. Many other insects are also attracted to wildfires, although they typically arrive later.

In an area northwest of Stora Laxsjön in Medelpad, SCA conducted a prescribed burning in 2014, and five years later, some effects are visible. Among other findings, SCA has identified traces of the rare bark beetle Stephanopachys linearis, which thrives in fire-damaged trees.

A feast for woodpeckers

The first two years after a controlled burning are always rich with woodpeckers because there are an abundance of insect larvae to feast on. Evidence of woodpecker activity is easy to spot here, as they have stripped bark off several birch trees in search of larvae beneath.

On other birch trees, the fungus Daldinia loculate is growing. This fungus appears as small black ping pong-like balls on the white trunks. Although the fungus exists inside all birch trees, its fruiting bodies, visible on the surface, only develop when the trees die in a fire.

This fungus serves as a habitat for several rare insects. Some live within the fruiting body itself, while others bore into the tree trunk directly next to it. The presence of burn crust fungus is a strong indicator of a successful controlled burn.

Sallow gains a chance

We weave through soot-blackened pine trees and dying spruces. On the forest floor, most of the mosses and lichens have burned away, creating space for new life to flourish. Fireweed and raspberry plants thrive here, and there are many young, slender sallow saplings. These sallows would not have existed without the fire, which cleared away the mosses and lichens and exposed the soil underneath. Sallow seeds require bare mineral soil to sprout.

Sallow is one of the most valuable tree species in Swedish forests. It plays a critical role in supporting bumblebees, butterflies, and other pollinators because it blooms very early in the spring. Often referred to as "nature's most important breakfast," sallow has become scarce in Sweden today. Therefore, it is essential to undertake measures that benefit this species.

A short distance away lies a silver-toned, old pine log, its underside completely charred. This demonstrates how a burn can provide ecological benefits for centuries. The pine log will serve as a vital resource for rare insects and lichens over an extended period. It may take hundreds of years for it to fully decompose, providing habitat value for many species along the way, including those that depend on charred wood.

Photo: Michael Engman