SR12 How does manipulation of dead wood affect forest biodiversity?

What are the possibilities of conserving or restoring the biodiversity of a forest through manipulation of its content of dead wood? Mistra EviEM examines the consequences for diversity of three kinds of manipulation: creation of dead wood (e.g. through girdling of trees), addition of dead wood from elsewhere, and prescribed burning.

Girdled spruce trees. Photo: Göran Eriksson / Länsstyrelsen i Jämtland.

Girdled spruce trees. Photo: Göran Eriksson / Länsstyrelsen i Jämtland.

Review status

Several different interventions can change the occurrence of dead wood

Dead wood is a key factor for biodiversity in most forest ecosystems. It is also the most critical resource lost when natural forests are converted into production forests. In recent years, many attempts have been made to remedy the current lack of dead wood in forests that are (or have been) under commercial management. Nonetheless, it is not entirely clear to what extent such interventions are beneficial for flora and fauna.

In 2014-2015, EviEM produced a systematic map of available evidence on how various kinds of management affect biodiversity in protected forests (see the SR6 review). We identified more than 800 studies that addressed this issue. Many of them described interventions that affected the occurrence of dead wood and saproxylic species. We have now decided to proceed with a full systematic review of the results presented in the latter set of studies.

The primary aim of the systematic review is to clarify how forest biodiversity is affected by manipulation of the quantity or quality of dead wood. We will examine three kinds of manipulation:

  • Creation of dead wood (e.g. through girdling or felling of trees)
  • Addition of dead wood from elsewhere
  • Prescribed burning

We will summarise reported effects of such interventions on all kinds of species except the trees themselves.

The ultimate purpose of the review is to investigate whether these kinds of manipulation of dead wood are useful as means of conserving or restoring biodiversity in forest reserves and other forests set aside from commercial forestry. Nonetheless, we will also include any useful studies made in forests under commercial management. Our focus will be on forest types represented in Sweden, but we will include relevant studies made in boreal or temperate forests anywhere in the world.

The review team that produced the SR6 systematic map will also conduct the review of dead-wood manipulation. The team is chaired by Bengt Gunnar (Bege) Jonsson, professor of plant ecology at Mid Sweden University in Sundsvall, and Claes Bernes, EviEM, acts as a project manager.

A detailed plan for how the dead-wood review is to be conducted was published on August 30, 2016 (see link in the margin at right).

Review team

Bengt Gunnar (Bege) Jonsson (Chair), Dept. of Natural Sciences, Mid Sweden University, Sundsvall, Sweden
Kaisa Junninen, Natural Heritage Services, Metsähallitus, Joensuu, Finland
Asko Lõhmus, Inst. of Ecology and Earth Sciences, Tartu University, Estonia
Ellen Macdonald, University of Alberta, Edmonton, Canada
Jörg Müller, Bavarian Forest National Park, Grafenau, Germany
Claes Bernes (project manager), EviEM, Stockholm, Sweden
Jennie Sandström (project assistant), Dept. of Natural Sciences, Mid Sweden University, Sundsvall, Sweden

The review team in April 2014. Standing, from left: Jörg Müller, Bege Jonsson, Asko Lõhmus, Claes Bernes, Ellen Macdonald, Kaisa Junninen. In front: Jennie Sandström and Miriam Matheis (master's student). Photo: Sif Johansson.

The review team in April 2014. Standing, from left: Jörg Müller, Bege Jonsson, Asko Lõhmus, Claes Bernes, Ellen Macdonald, Kaisa Junninen. In front: Jennie Sandström and Miriam Matheis (master’s student). Photo: Sif Johansson.