Last updated at: 28-02-2022

Project title

ForRISK - Forest density reduction to minimize the vulnerability of Norway spruce and silver fir to extreme drought – a risk assessment.

Project Consortium. Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Switzerland: Andreas Rigling (PI), Alessandra Bottero, Arthur Gessler, David I. Forrester, Arun K. Bose; Université de Lorraine, INRAE, AgroParisTech, UMR Silva, France:  Matthias Cuntz, Julien Sainte-Marie, James Ryder; Chair of Forestry Economics and Forest Planning, University of Freiburg, Germany: Marc Hanewinkel, Rasoul Yousepfour, Juan Carlos Zamora; Forest Research Institute of Baden-Württemberg FVA, Germany:  Ulrich Kohnle; UMR RECOVER, Aix Marseille University, IRSTEA, France: Maxime Cailleret; Chair of Forest Ecology, ETH Zürich, Switzerland:  Harald Bugmann, Mathieu Lévesque; Chair of Silviculture, University of Freiburg, Germany: Jürgen Bauhus, Julia Schwarz.


Andreas Rigling (WSL)


03.2017-02.2020 (extended to 12.2020)


ERA-NET Sumforest. Sumforest was funded by the European Union under Grant Agreement No. 606803. The ERA-NET Sumforest project ForRISK is funded in Switzerland through the Federal Office for the Environment FOEN (Grant No. 05.0602.PZ / P382-0487), in France through the French National Research Agency ANR (Grant No. ANR-16-SUMF-0001-01) and in Germany through the Federal Ministry for Food and Agriculture BMEL (FKZ: 2816ERA04S).

Problem description

The project investigates mechanisms and processes behind the vulnerability of forests to drought to identify management strategies that can support the adaptation (resilience) of these ecosystems to climate change.


Identify management options to mitigate the negative effects of drought on forests, and thus creating more resilient ecosystems. The main focus is adaptation. The goal is to produce a policy brief with optimized management strategies that are developed following a risk assessment and the economic evaluation of different management scenarios. A workshop with stakeholders aims to promote the implementation of the project.


Forest management.

Forest type

Mixed managed mature stands of Abies alba and Picea abies (main species).


Management actions in order to increase resilience: reduce tree size and stand density (to a certain extent), reduce the proportion of spruce in the stands, favor admixtures.


Southwestern Germany and Switzerland. For the exact location of the study sites see

Visible effect

There are no visible effects from the project yet.




Not applicable/ not known.


The sites in Germany, part of the shelterwood experiment, are measured at periodic intervals (every 5 years) until ca. 2030. The sites in Switzerland, part of the EFM network (, are periodically measured every 5-10 years.


The approach developed in the project can be adopted in other regions. The findings of the project may be transferred to comparable forest ecosystems and sites.


Brochure Sumforest – ForRISK; project website; scientific articles are in preparation and/or in review; project outcomes kept up-to-date at