Record breaking temperatures, minimal rainfall, drying rivers and burning forests. The news from this summer show how acutely the warming climate is affecting our environment and lives. To me, the damages to forests due to fires, drought and insect outbreaks are particularly worrisome as we as a society are counting on forests to sequester our carbon emissions, to replace the fossil fuel products and to foster biodiversity that is rapidly declining. This concern on the capacity of forests to cope with increased disturbances started years ago and led me to pursue a PhD on forest resilience and how it could be improved with forest management. Now it is time to summarise my work from the last four years.
To be able to increase the resilience of forests with forest management, we first need to know what it is. The term resilience has many different definitions and there is no commonly approved way to measure it. To make it a more useful concept in forest management, I, together with colleagues, took four steps to move from understanding what resilience means as a concept to exploring, how it can be adopted in forest management.
From definitions to trade offs
As a first step, we looked at how resilience is defined and used in scientific literature. We provided a frame for navigating the different definitions of resilience in the forest science literature and gave examples how it can be measured. We did this by reviewing a vast amount of literature, where three common concepts of resilience dominate: engineering resilience (the time that it takes to recover after a disturbance), ecological resilience (the capacity to maintain the same identity, i.e., to remain forest, despite the disturbance), and social-ecological resilience (the capacity of the forests and societies surrounding it to withstand and adapt to changes and disturbances). We analysed how similar and how different these three concepts are and how they were measured or assessed. We found that the different definitions of resilience are not contrasting but rather complimentary to one another. They form a nested hierarchy where engineering resilience is nested inside ecological resilience, which in turn is nested inside the social-ecological resilience. The decision on which one to use depends on the complexity of the research or management question with engineering resilience used for simpler questions and ecological and social-ecological resilience for more complex ones. Therefore, instead of debating on the correct definition to use, forest managers should carefully determine of what part of the forest or forest value chain, to what they need to increase the resilience to, and who are likely to be influenced by their decisions.
As a second step, we developed a Principle, Criteria, and Indicator framework to help forest managers to identify how forest management objectives and emerging trade-offs influence resilience and how the trade-offs could be dealt with and balanced to achieve a more resilient forest. The framework showed that the management goals that forest owners and managers have influences the trade-offs in forest management as well as the level of resilience of the forests and the surrounding society. Therefore, the steps to achieve resilient forests are different for different management goals.
How science can better support forest management
As a third step, we analysed how dendrometers, devices measuring the tree stem diameter change, could be used as a tool to monitor tree resilience to drought. The analysis showed that, while not yet ready to be used in the practical forest management level, the dendrometers have the potential to inform forest managers about the times when trees are experiencing stress and how resilient they are to drought.
As the final step, we explored how to improve the transfer of knowledge and experiences between scientists and forest management practitioners, with the focus on how to improve forest resilience to disturbances in practical forest management. We found that while forest professionals value the exchange between science and practice, in some cases the evidence behind the effectiveness of the forest management measures they propose to increase resilience is weak. Moreover, many forest professionals face considerable barriers in changing forest management to increase resilience due to the lack of locally relevant information and financial or professional capacities.
Collaboration for more resilient forests
To conclude the results of the four steps, the research we conducted provided remarkable advances on understanding how forests could be made more resilient with management. Our results showed that resilience can be implemented into forest management with a variety of forest management goals. The future research should focus on developing, together with forest owners and managers, resilience indicators for forests under different management regimes across Europe. Moreover, efforts to study the impacts of different forest management measures on resilience to disturbances should be increased. However, forest-related policies and management practices should already use measures to increase resilience of forests to ensure the provisioning of ecosystem services.
What would I want to say to forest managers based on the results of my thesis? I would say know your forest and know who are the people around you interacting with your forests. Engage with them and work with them. Ask scientists to help you with the questions you don’t know the answer to. We might not know it either yet, but together we have a higher chance finding it out. It is important that we work together as the future is looking more and more uncertain. And as a great wizard once said, we can only decide what to do with the time that is given to us.