SUMMARY OF MAIN FINDINGS
Finnish forests have undergone significant changes from their pristine state, leading to a continuing decline in their biodiversity and threatening their ecosystem integrity. In this research, I investigated how to reconcile biodiversity conservation with multiple human needs provided by boreal forest landscapes. Taking a novel approach, I considered forest management practices as a source of landscape heterogeneity and explored how a diversity of management methods could benefit biodiversity at the landscape level.
The results deliver valuable insights for effectively managing Finnish production forests to preserve biodiversity. I found that using an increasingly diverse set of management methods can create more diverse habitats in forest landscapes and support greater biodiversity. Different combinations of delayed harvest, absence of thinning, and continuous forestry are valuable management options. Further, to maintain biodiversity and important ecosystem services (for example, recreational value and climate change mitigation), extensive management practices, such as continuous cover forestry, must become dominant in Finnish forest landscapes. This could be achieved through a “Triad” planning approach, where forest landscapes are divided into three management zones: increased area of forest reserves for biodiversity conservation, a minimal intensive management zone for wood production, and a large zone under extensive management where both production and conservation are shared objectives.
The key finding of this research project is that management diversity, including forest protection, appears to be a flexible and efficient way to improve biodiversity and the ecological integrity of boreal forest ecosystems, while still maintaining reasonable levels of timber production and other ecosystem services. Importantly, forest management strategies need to consider the range of benefits provided to human society, including recreation, health, and cultural and economic collectable goods (such as berries and mushrooms).
In this project, I defined five hypotheses on how management diversity can benefit biodiversity through (i) habitat diversity, (ii) interactions between differently managed forest units, (iii) temporal variation in management, (iv) absence of management, and (iv) increased habitat connectivity (Duflot et al., 2022b).
Using forest growth simulations of forest management, I found that, indeed, increased diversity of management methods can create more diverse habitats in forest landscapes and support greater biodiversity. This can be achieved at relatively small economic costs; however, it requires careful selection of diverse management methods (Duflot et al., 2022a).
In another study, I tested the potential benefits of Triad landscape zoning approach, where the forest is divided into forest reserves, intensive and extensive management zones. I found that converting some part of a forest landscape into extensive management and protected areas will enhance multiple forest functions (for example recreation value and carbon stock), as well as biodiversity (Duflot et al. under review).
Finally, I contributed to a few other studies. We showed that the current Finnish forest structure greatly depart from historical and natural references with negative consequences on biodiversity (Mönkkönen et al., 2022). Meanwhile, we also demonstrated that continuous cover forestry should be a dominant management if we aim at promoting multiple forest functions and biodiversity, while still maintaining some level of timber production (Eyvindson et al., 2021).
These results provide insights on how to effectively manage production forest landscapes to preserve biodiversity in the Finnish boreal context. The result of this project will lead to further research aiming at investigating further the temporal and spatial aspect of landscape planning.