Link zu WSL Hauptseite Swiss Federal Institute for Forest, Snow and Landscape Research WSL
Duration: 2011 - 2019

Experimental field test of six exotic tree species

An international cooperative project of research institutions and universities (lead: LWF Bayern)

Versuchsfläche Mutrux
What are exotic tree species?

Exotic tree species are species introduced to an area where they do not occur naturally. Such species must initially be planted, but may be able to regenerate naturally later.

  Zedern-Stangenholz Suchy  
  Fig. 1: Cedar in a pole stand
near Suchy (Canton of Vaud)
Why planting exotic tree species?

For centuries, plant lovers, gardeners and foresters have been experimenting with exotic tree species in parks, gardens and forests. Their motivation is the fascination for the alien, the admiration for giant trees and an economic interest in fast growing timber trees. Most exotic tree species proved to be a failure. Few of them continue to be used, e.g., the Monterey pine (Pinus radiata), a species used worldwide in commercial plantations, and in Switzerland Douglas fir (Pseudotsuga menziesii) and red oak (Quercus rubra). Moreover, few experimental plantations with Atlas cedar (Cedrus atlantica) exist in Switzerland (Fig. 1).
Today there is a revived interest in exotic tree species since it is feared that climate change could cause failure of tree species with economic importance such as Norway spruce (Picea abies). Therefore, as a replacement, species are sought with similar wood properties but which sustain a warmer and drier climate.

What is the aim of the research project ‚Exotic tree species‘?

The project aims at testing the suitability of 6 little-known exotic tree species for use in a future warmer and drier climate. An additional objective is to check whether the roots of the selected tree species will be sufficiently colonized with mycorrhizal fungi at the target sites.

Which methods are used?

The project is based on a long-term experimental field trial at 5 sites in Germany, Austria and Switzerland. The Swiss site is located near Mutrux (Canton of Vaud). More information regarding the research methods is provided here.

Expected results and relevance for practical application

The field trial enables us to judge how well the species survive, grow and stay free of pests and diseases, as well as to what degree their roots are mycorrhized.
After a few years, the project will result in tentative recommendations for further use of the tested tree species. With increasing duration of the trial, the recommendations will become more robust. The goal is not to replace the tree species currently present in Switzerland, but to mix suitable exotic species, in small proportions, with well-proven species.


The Swiss part of the project is funded through the research program ‚Forests and climate change‘ (in German) of the Federal Office of the Environment and WSL, and through a contribution of the Canton of Vaud.


Peter Brang
Phone: 0041 (0)44 739 24 86

Keywords Silviculture, tree species, climate change, permanent plot, experiment field trial