Preventing the spread of new pathogens in Nordic forests to secure sustainable forestry in growing bioeconomy


Coordinator: Johanna Witzell, SLU,

Funding: 1 005 000 SEK

Duration: 2019–2021


This project will take a broad view of the problems with invasive pathogens.

Text: Mats Hannerz


Fir needle (pine) close up. Photo.

Diplodia pinea is a pathogen common in southern Europe, which has spread north, possibly due to climate warming. It was discovered in Sweden in 2013, and has since attacked pine stands so severely that they had to be harvested prematurely. Photo: Steven Munson, USDA Forest Service. CC BY-SA 3.0

In recent decades, Europe has experienced an exponential increase in problems with introduced, invasive forest pathogens.

The Nordic countries have seen the hardwoods elm and ash being decimated by pathogens. Scots pine, a keystone species in the Nordic forests, has been exposed to several new pathogens such as Dothistroma septosporum, D. pini, Lecanosticta acicula, Diplodia sapinea, and pitch canker caused by Fusarium circinatum. Other problems are related to Phytophthora species, which can infect a broad range of host tree species.

Trade and climate

International trade in plants and soil is an important pathway for new pathogens, and the problems will probably increase with climate change. Drought periods may stress the host trees, and warmer and wetter winters may expand the range of introduced pathogens.

The project will combine expertise from across the Nordic countries to improve methods of early and accurate detection of new pathogens. There are many methods for detecting pathogens, such as gaseous signals, DNA/RNA or spectral changes in infected plants.

Knowledge about the spreading ways

The project will also increase knowledge about pathways of spreading new diseases. For instance, Rhododendron plants have been implicated as a source of the spread of Phytophthora species.

Another outcome, besides new scientific information about invasive, introduced forest pathogens, will be a multicriteria decision analysis tool to improve biosecurity in relation to alien invasive forest pathogens.


Project name: Preventing the spread of new pathogens in Nordic forests to secure sustainable forestry in growing bioeconomy

Cooperation between: SLU (Sweden), Luke (Finland), Nibio (Norway), University of Copenhagen (Denmark), Estonian University of Life Sciences (Estonia), Institute of Forestry (Lithuania), Nature Research Center (Lithuania), Friodlingens Riksorganisation (Sweden), Rhododendronsällskapet (Sweden) and UPM Joroisten taimitarha (nursery, Finland).


Read the full edition of News&Views (PDF)


Comments are closed.