With the publication of the European Green Deal, the European Union has committed to reaching carbon neutrality by 2050. The envisaged reductions of direct greenhouse gases emissions are seen as technically feasible, but if a wrong path is pursued, significant unintended impacts across borders, sectors, societies and ecosystems may follow. Without the insights gained from an impact assessment framework reaching beyond the techno-economic perspective, the pursuit of direct emission reductions may lead to counterproductive outcomes in the long run. We discuss the opportunities and challenges related to the creation and use of an integrated assessment framework built to inform the European Commission on the path to decarbonisation. The framework is peculiar in that it goes beyond existing ones in its scope, depth and cross-scale coverage, by use of numerous specialised models and case studies. We find challenges of consistency that can be overcome by linking modelling tools iteratively in some cases, harmonising modelling assumptions in others, comparing model outputs in others. We find the highest added value of the framework in additional insights it provides on the technical feasibility of decarbonisation pathways, on vulnerability aspects and on unintended environmental and health impacts on national and sub-national scale.

Landscape approaches are important for planning of urban sprawl in peri-urban landscapes, continuously emerging in many metropolitan regions. In the case of Stockholm Region, land-take and incremental urbanisation is a continouous process, while the regional development plan has ambitions to steer the overall development in a sustainable direction. This plan contains a green infrastructure effort building on a set of green wedges, mainly serving as support to the needs of the city and suburbs and their citizens. This initiative differ from the later green infrastructure action plan provided by the county administrative board, related to the EU biodiversity strategy and guidelines. The latter has a different approach, mainly targeting biodiversity goals as well as ecosystem services. These approaches differ from each other in several ways while both have unclear roles when it comes to municipal planning on different levels. Furthermore, the municipalities have their own initiatives when it comes to green infrastructure and nature-based solutions and it is not clear how the different planning tiers are linked to each other, to planning and management, and to multifunctional landscapes. The aim of the REPLAN project is to investigate how the different green infrastructure initiatives are linked to planning, to each other on different scales, and whether they can serve multi-functional landscapes when it comes to biodiversity and different ecosystem services. The REPLAN project involves stakeholders and practitioners on different planning levels for co-producing knowledge, methods and strategies for green infrastructure and nature-based solutions to serve as tools for sustainable transition of metropolitan areas and their peri-urban landscapes.

The demand for timber, bioenergy feedstock and other forest products, leading to intensified forest harvesting, is expected to increase in the coming decades. A reduction in the delivery of forest ecosystem services and, specifically, biodiversity, including the provision of habitats for mature-forest-dwelling raptors, has been attributed to the intensification of forest exploitation. Therefore, in order to adopt adequate conservation measures to create a timely buffer against the consequences of increased harvesting, it is critically important to understand how the availability of nesting habitats for protected species will fluctuate in the future landscape. In this study, using the LandSim tool, we modelled the dynamics of the forests and nesting habitat availability for the forest-nesting raptor, the lesser spotted eagle Clanga pomarina, for the next 50 years in eastern Lithuania, Central Europe. Our findings indicate that the share of forests available for final harvesting is expected to increase rapidly in the coming decades due to a large amount of forest stands reaching a mature age, if current forest management practices, despite them being considered as relatively conservative, are continued. As a consequence, the availability of nesting habitats will constantly decrease in nesting territories, as well as elsewhere in the landscape, in the coming decades. We suggest that species conservation strategies should not only incorporate directly targeted measures to protect nest sites from destruction and disturbance, but also, at the very least, preserve a sufficient amount of nesting habitats in areas inhabited by eagle pairs and, at best, at the landscape scale.

Intensified forestry can be seen as a solution to climate change mitigation and securing energy supply, increasing the production of forest bioenergy feedstock as a substitution for fossil fuels. However, it may come with detrimental impacts on forest biodiversity, especially related to older forests. The aim of this study was to assess the sustainability of intensified forestry from climate-energy and biodiversity perspectives, targeting forest bird species. For this purpose, we applied the Landscape simulation and Ecological Assessment (LEcA) tool to the study area of Lithuania, having high ambitions for renewables and high forest biodiversity. With LEcA, we simulated forest growth and management for 100 years with two forest management strategies: Business As Usual (BAU) and Intensive forestry (INT), the latter with the purpose to fulfil renewable energy goals. With both strategies, the biomass yields increased well above the yields of the reference year, while the biodiversity indicators related to forest bird habitat to different degrees show the opposite, with lower levels than for the reference year. Furthermore, Strategy INT resulted in small-to-no benefits in the long run concerning potential biomass harvesting, while substantially affecting the biodiversity indicators negatively. The model results have the potential to inform policy and forest management planning concerning several sustainability goals simultaneously.

Demands on forest bioenergy feedstock are expected to increase in many countries due to climate change mitigation. However, sustainable use of forest biomass resources can be ensured only if local and landscape conditions are taken into account, linking energy use to its resource base. The aim of this study was to analyse the forest biomass potential for Lithuania’s energy pathways, while comparing the projected demand of forest bioenergy feedstock with resource projections. This was performed using the Landscape simulation and Ecological Assessment (LEcA) tool and the energy model MESSAGE. Biomass demand can be met up to 2050, after which demands under a Biomass Low pathway can still be met by the domestic forest resource if other wood uses are reduced, while Biomass High leads to a biomass deficit regarding domestic forest resource. Information exchange between the energy model and the LEcA tool enables an integrated sustainability assessment, and may contribute to a sustainable and efficient use of forest as a bioenergy feedstock resource.

Forest management tends to intensify in many countries due to climate change mitigation, which require more forest bioenergy as substitution for fossil fuel. However, the intensified forestry may be detrimental to biodiversity, especially for species dependent on old forest habitat. In order to simultaneously assess production of forest bioenergy feedstock and habitat potential for biodiversity, we developed the Landscape simulation and Ecological Assessment (LEcA) tool, linking simulation of forest growth and management (LandSim), a yield calculator, and a habitat assessment model. The aim was to integrate production of forest bioenergy feedstock, industrial wood, and biodiversity tied to mature and old forest, in a sustainability assessment of forest bioenergy options. The study area was the country of Lithuania where two forest management scenarios were applied, business-as-usual (BAU) and intensive-forestry (INT). The landscape simulation was run for a 100 years period with 5 year time steps. Forest biodiversity was represented by area of old forest as well as nesting habitat for two model species, Lesser Spotted Eagle (Clanga pomarina) preferring forest edges, and Black Stork (Ciconia nigra) preferring interior forest. The results showed that forest bioenergy yields may be higher in the INT scenario during the first decades of the simulation period, but in the long run will only be slightly higher compared to the BAU scenario. However, the impacts on the habitat of the forest birds would be considerable, where the habitat area would be 14% smaller for C. pomarina and 17% smaller for C. nigra, in the INT scenario compared to BAU. The landscape simulation showed that there may be conflicts between sustainability objectives related to climate change mitigation and biodiversity, and that intensive forestry may not necessarily be an effective mitigation measure. The model results has potential to inform policy and planning concerning several sustainability aspects.

Forests are important for climate change mitigation by providing bioenergy feedstock to substitute fossil fuels, as well as for carbon storage, while they are also important for other ecosystem services. The REEEM project targets to gain a comprehensive understanding of the system-wide implications of energy strategies in support of transitions to a competitive low-carbon EU society. The current REEEM case study of Lithuania aims to i) analyse the forest biomass potential for Lithuania using the LEcA tool, assessing impacts on ecosystem services of alternative forest management strategies, and compare to energy pathways including forest bioenergy feedstock as a RES; and ii) develop and discuss linking between the energy assessment model that project the energy pathways, in this case the MESSAGE model, and the LEcA tool to enable iterations and information exchange.

Two alternative pathways were run with the MESSAGE model of the use of forest bioenergy feedstock in the development of the Lithuanian energy sector, Biomass Low and Biomass High. This initiated the simulation of forest growth and management of Lithuania with the LEcA tool for 2015-2050 and beyond, applying a Business-As-Usual (BAU) forest management strategy. Based on these results, a second, more intensive (INT) forest management strategy was developed and applied in order to increase the yields. From the output of the simulations of both strategies, the development of five ecosystem services was assessed: forest bioenergy feedstock, industrial wood, carbon storage in the forest, recreation area and habitat supporting biodiversity. For bioenergy feedstock, environmental restrictions and transport distances for harvest residues were considered. In addition, different assumptions about the use of forest compartments for bioenergy purposes were tested.

The estimations of bioenergy feedstock were comparable with the empirical data. However concerning logging residues, the transport distances affecting economy and climate impacts need more considerations, as those may become more pronounced in the future. It could also be concluded that the assumptions concerning the allocation of different forest compartments as bioenergy feedstock would highly influence the results. In the comparison with energy pathways, though, assumptions based on empirical data came much closer than assumptions following forestry manuals. When comparing results with the energy pathways, it was still difficult to estimate with any precision the bioenergy feedstock availability. Looking at the overall situation applying allocation assumptions based on empirical data, the results indicated that during the period up to around 2040 supply and demand may not be so far apart from each other with Strategy BAU, and the supply exceeded the demand with Strategy INT. However, closer to year 2050 when the energy pathways projected a much higher use of forest biomass, it may be more difficult to meet the demands with either of the forest management strategies.

With Strategy INT, the overall yield was around 10% higher than with Strategy BAU, with the highest yields in the beginning of the period. However, the yields were not timing well with the energy pathways, since the major increase would be needed after around year 2040. Still, these results served to illustrate that when increasing the yields above a certain threshold, the resources may be exhausted in the long run. As well, comparing strategies BAU and INT, it could be shown that there are trade-offs to be expected between bioenergy feedstock and industrial wood on the one hand, and carbon storage, recreation and habitat supporting biodiversity on the other hand.

The LEcA tool can simulate forest growth and management with modest data requirements, which allows for exploring forest management strategies across the whole landscape. The GIS-based approach to the bioenergy feedstock problem, using data that in this context has a high geographical resolution, gives more detailed and localised information than what would be possible in more lumped approaches. The possibilities to spatially allocate and as well aggregate spatially explicit information makes the LEcA tool suitable for flexible model linking. Not only impacts can be assessed, but for instance constraints can be formulated for the assessed ecosystem services, so that they should not go below a certain value in any time period, which could also be fed back to the energy model.

For linking between the energy model and the LEcA tool, the first steps of information exchange were recognized and tested. The energy pathways created by the MESSAGE model initiated the forest management strategy BAU, from which the results concerning bioenergy feedstock yield was fed back and compared with the pathways. From this comparison, the second forest management strategy INT was developed, targeting higher yields. In future work these first steps will be further developed, preparing for full linkage between models. The results from the ecosystem service assessment will be fed back to the energy model for informed adjustments concerning a sustainable production of forest bioenergy feedstock. In this way, the links between energy assessment and ecosystem services could be strengthened in a more integrated assessment, targeting to inform energy policy and to increase the sustainability of forest bioenergy options.

Demands on forest bioenergy feedstock are projected to increase in many countries due to climate change mitigation requiring renewable energy sources. However, national energy planning may need to be informed about local and landscape conditions in order to promote sustainable use of forest biomass resources as well as other ecosystem services. Therefore, integrated modelling of energy use and resource availability is called for.

The aim of this study was to analyse the forest biomass potential for Lithuania for energy pathways, while comparing the projected use of forest bioenergy feedstock with available resources applying environmental restrictions. This was performed using the Landscape simulation and Ecological Assessment (LEcA) tool and the energy model MESSAGE, while discussing links between these in order to better connect energy planning on national and local levels.

The results showed that under a Biomass-Low pathway and business-as-usual forest management, demands would be met up to 2050, while a Biomass-High pathway and more intensive forest management may lead to difficulties to meet the demands in the later end of the period. Linking the energy model with the LEcA tool enable iterations and information exchange for comparison between demand and supply, and may contribute to a sustainable and efficient use of forest as bioenergy feedstock resource.