Over a decade ago, a series of experiments were conducted in 18 forests northern Sweden by researchers from SLU. The experiment involved actions to mimic large-scale natural disturbances that affect entire stands or landscapes, such as wildfires, as well as small-scale natural disturbances that create small gaps in stands. Both of these types of disturbances have historically shaped our forests. One-third of the forest stands were burned, one-third were gap-cut to create openings with sunlight, and one-third were left as controls.
In a new film about forest management for conservation, viewers can visit some of these experimental forests and learn about the results that researchers have observed so far. The film is in Swedish, but it offers the option to select English subtitles.
Many endangered insect species are dependent on deadwood and they appear only after the trees have died and started to break down due to fungi and other factors. Thus, a significant focus of conservation efforts is to create deadwood, which was done in various ways when the open gaps were created. "We've cut and laid down trees, , created high stumps, and even pushed over trees to mimic storm damage," says Therese Löfroth, a researcher at SLU. Additionally, some trees were ring-barked to slowly die and contribute to the deadwood.
Burned forests attract many species
The burned forest areas immediately attracted numerous insects and birds, such as the three-toed woodpecker, which is often found in old-growth forests. Over time, even more endangered species and fungi will be drawn to these burned areas.
The forests in the experiment are owned by Holmen and are typical production stands. "It's possible to create conservation values in all types of forests; we don't need to focus solely on forests that already have high conservation values from the start," says Joakim Hjältén, a professor at SLU.
In the central part of Sweden, Albin Larsson Ekström is working on scientifically evaluating conservation measures taken to protect the critically endangered white-backed woodpecker. The bird requires extensive areas of deciduous forest, both dead and living. "The white-backed woodpecker is an umbrella species; many other endangered plant and animal species thrive in the same environments and will also benefit," says Albin Larsson Ekström.