Conservation of resistant ash genotypes to maintain full range of ecosystem services


Coordinator: Mateusz Liziniewicz, Skogforsk,

Funding: 1 050 000 SEK

Duration: 2019–2021


Project Background

Trees in high grass. Photo.At present, Nordic and Baltic foresters no longer rely on ash as a timber species, not even as a supportive species in silviculture of temperate broadleaved forests. Forest managers and land owners are replacing ash with less productive and less valuable species on sites suitable for ash. In addition, the flexibility provided by early and abundant natural regeneration is no longer reliable because of the annual ‘knock-down-effect’ by the disease. From a biodiversity perspective, the continuous decline of the ash tree population will inevitably induce an ‘ecological cascade effect’ (i.e. secondary extinctions) of hundreds of distinctive taxa, especially those having high- or obligate associations to ash. In the future, the values forgone by not being able to utilize ash will likely become even larger and pose a high risk to the provision of ecosystem services that are so important for temperate broadleaved forest ecology.

Fortunately, Nordic and Baltic forest geneticists already ten years ago, demonstrated large genotypic variation among native ash trees in their susceptibility to the ADB pathogen (see review in McKinney et al 2014). Typically, less than 5% of the population shows better tolerance to the disease. Several studies provide evidence that susceptibility to ADB is under strong genetic control and that considerable gain can be achieved through selection and breeding (Stener 2013, 2016; McKinney 2011; Pliura et al. 2011). Furthermore, the findings of low genotype x environment interaction in the Danish and Swedish studies mentioned above, indicate that clonal performance is not site-dependent, which will simplify the selection and breeding process. While some advances have also been made towards developing a more resistant population with selected and tested ash trees, coordinated efforts are urgently needed in order to achieve successful reforestation and restoration across the region.

Project Goal

The general aim of the proposed project is to continue the efforts started in partnering Nordic and Baltic countries leading to restoration of ash trees in the region. The specific objective is to develop and establish a set of 2nd generation genetic test trials that can be crucial for ash conservation


Project Participants

Lene Rostgaard Nielsen and Erik D. Kjær, University of Copenhagen, Denmark

Mari Mette Tollefsrud and Tor Myking, NIBO, Norway

Diana Marčiulynienė and Alfas Pliūra, Lithuanian Research Centre for Agriculture and Forestry, Lithauen

Michelle Cleary, SLU, Sweden

Lars-Göran Stener and Mateusz Lizniewicz, Skogforsk, Sweden


More information about the project – Genetic selection will save the ash

SNS-126 – Annual report 2019 (PDF)

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