SLU news

Old burned areas are popular habitats for browsing moose

Published: 01 June 2023
Forest with burned trees. Photo.

Forest fires can create plenty of forage for moose. This is shown by a study conducted by SLU researchers on forests burned more than ten years ago. The researchers also detected that more forage suitable for moose was created in areas burned by wildfires than where prescribed burns were carried out to benefit biodiversity.

A forest fire changes the entire landscape and creates habitats that many species need for their survival. A fire creates a lot of dead wood , and the tar concentration of the Scots pine trees that survive can live for a very long time (this is a special habitat for some insect species). Today, the area of forest that burns has decreased significantly due to effective fire suppression over the last century.

One way to benefit fire-dependent species is to carry out controlled burning, so-called conservation burning. For safety reasons, these are often smaller in size and of lower intensity than wildfires.

In a new SLU study, researchers have studied how forest fires affect the amount of forage suitable for moose, and to what extent moose use these burned forests.

- The results show that wildfires produced a greater diversity of forage, more twigs, and especially more leaves, compared to the prescribed burns. We also saw that the moose seem to utilize and browse more in the naturally-burned areas than in prescribed burns or forests that have not burned, says Emelie Fredriksson, former doctoral student at SLU.

The study was conducted on just over ten-year-old burned forests in Norrbotten and adjacent control areas that have not burned. There, the researchers investigated forage availability, browsing pressure and the moose's use of these environments.

- We saw that large forest fires create good fodder resources for moose. Conservation burning can indeed be used to improve forage availability (twigs, but even more for leaves), which are an important food resource for moose. However, ideally the burning should be even more similar to a wildfire in both a large area and high fire intensity, says Therese Löfroth, Senior Lecturer at SLU.

Read the scientific article

Emelie Fredriksson, Märtha Wallgren & Therese Löfroth. Wildfire and prescribed burning impact moose forage availability and browsing levels in the northern boreal forest. Scandinavian Journal of Forest Research. Volume 38, 2023 - Issue 1-2: https://doi.org/10.1080/02827581.2023.2184489

Facts:

How the study was conducted

The researchers inventoried forests burned a bit over ten-year-old in Norrbotten, of which three were natural fires and five were nature conservation burns. At sampling sites, piles of moose droppings, tree height, and degree of coverage of various plants (such as blueberries) were measured, and a detailed inventory of trees at grazing height was made. They counted all the twigs on the trees as a measure of available forage and noted any browsed twigs. In total, the inventory included 1611 smaller trees in the 54 circle sample areas.

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