Epsilon Archive for Student Projects

Abstract

European beech (Fagus sylvatica) forests have been heavily altered through centuries of forest management resulting in homogenous stand structures, reduced dead wood availability and a lack of important habitat structures associated with old-growth forests. As the European Union’s Nature Restoration Regulation (NRR) is enacted there is an increasing need to evaluate restoration methods capable of accelerating the development of ecologically valuable forest.
This thesis analyses whether veteranisation and mortality inducing treatments can accelerate structural restoration in previously managed beech forest stands. The study was conducted in the nature reserve “Osbecks boksskogar” in southern Sweden where restorative treatments have been applied since 2008. A chronosequense of 39 plots created between 2008 and 2023 were inventoried and analysed together with recently established control plots. The treatments included ring barking, partial ring barking, high stump creation, creation of living high stumps, basal bark damage and artificial cavity creation. Variables related to mortality, vitality, dead wood occurrence, and decay stage were inventoried and statistically analysed.
The results show that veteranisation and ring barking increased structural heterogeneity significantly compared to untreated control plots. Mortality inducing treatments such as ring barking and high stump creation generated substantial amounts of standing and lying dead wood across multiple decay classes. Lower intensity treatments created long-lasting tree related microhabitats and generally generated low mortality in treated trees. Dead wood volume and decay variability increased with time since treatment and treated plots showed greater variation and volume of dead wood than control plots.
The study suggests that veteranisation and mortality inducing treatments can accelerate the development of structural characteristics otherwise associated with natural beech forests and sustain these characteristics over time. They may therefor function as effective restoration techniques for increasing the availability of niche habitat and key dead wood structures in stands previously managed for wood production.