The need to adapt to climate change as well as to secure the supply of energy has led to a shift in energy consumption from fossil fuel to renewables. In this context, forest biomass is a resource that is increasingly utilised for bioenergy purposes in Sweden, which along with the extraction of industrial wood may conflict with other sustainability goals such as those related to biodiversity conservation. In order to balance between main sustainability objectives, land zoning policies and related management regimes has been proposed, differentiating between the main management categories protected areas, multi-purpose forestry and intensive forestry. The aim of this project was to develop methods and tools for integrated sustainability assessment of forest biomass extraction, in particular from bioenergy and biodiversity perspectives.
For this purpose, the landscape simulator LandSim was developed and applied in a case study in Kronoberg County in southern Sweden. Forest growth and management was simulated in 5-year time steps for the period 2010-2110. The management followed two land zoning scenarios, one applying even-aged forestry on all forest land except for protected areas (EAF-tot), and one was applying continuous cover forestry on parts of the forest land, combined with protected areas and a shorter rotation time on the other parts (CCF-int). The outcome of the simulations was raster data on tree species, volume and age for each time step and scenario. From the outcome, harvested volumes and bioenergy feedstock yields were derived. The same outcome was used for an ecological network assessment, using the indicator Equivalent Connected Area (ECA) for two model species tied to mature and old coniferous and southern broadleaved forest, respectively.
The results showed that the EAF-tot scenario implied higher yields of biomass feedstock for bioenergy than the CCF-int scenario, while the CCF-int scenario displayed more even yields over the years. By contrast, the CCF-int scenario performed substantially better than the EAF-tot scenario when it came to the ECA indicators. However, the CCF-int scenario involved a range of assumptions mirroring major uncertainties on habitat suitability, which yielded separate results and thus will need further exploration. Moreover, in order to support the model species and related biodiversity components, the forest management would need to allow larger areas to become suitable habitat, as well as to plan for habitat amount and connectivity on landscape scale in order to not only increase habitat size but also ECAs. Conclusively, the modelling framework linking the landscape simulator with the ecological network model could be used for integrated sustainability assessment of bioenergy options, integrating main policy concerns when assessing renewable energy options.