The bio-based economy has been increasingly recognized in the sustainability debate over the last two decades, presented as a solution to a number of ecological and social challenges. Its premises include climate change mitigation, cleaner production processes, economic growth, and new employment opportunities. Yet, a transition to a bio-based economy is hampered by risk factors and uncertainties. In this paper, we explore the concept of a bio-based economy, focusing on opportunities of achieving sustainability, as well as challenges of a transition. Departing from an understanding of sustainability provided by the weak and strong sustainability paradigms, we first outline the definition and development of the bio-based economy from a theoretical perspective. Second, we use Sweden as an example of how a transition towards a bio-based economy has been evolving in practice. The review indicates that the proposed direction and strategies of the bio-based economy are promising, but sometimes contradictory, resulting in different views on the actions needed for its premises to be realized. Additionally, current developments adhere largely to the principles of the weak sustainability paradigm. In order for the bio-based economy to develop in accordance with the notion of strong sustainability, important steps to facilitate a transition would include acknowledging and addressing the trade-offs caused by biophysical and social limits to growth.

Climate change adaptation and mitigation strategies (CCAMS) are changes to the management of production forests motivated by the need to mitigate climate change, or adapt production forests to climate change risks. Sweden is employing CCAMS with unclear implications for biodiversity and forest ecosystem services (ES). Here, we synthesized evidence from 51 published scientific reviews, to evaluate the potential implications for biodiversity and a range of provisioning, regulating, and cultural ES, from the adoption of CCAMS relative to standard forestry practice. The CCAMS assessed were the adoption of (i) mixed-species stands, (ii) continuous cover forestry, (iii) altered rotation lengths, (iv) conversion to introduced tree species, (v) logging residue extraction, (vi) stand fertilization, and (vii) altered ditching/draining practices. We highlight the complexity of biodiversity and ES outcomes, identify knowledge gaps, and emphasize the importance of evidence-based decision making and landscape-scale planning when navigating choices involving the widespread adoption of CCAMS.

Climate change will bring about a consistent increase in temperatures. Annual precipitation rates are also expected to increase in boreal countries, but the seasonal distribution will be uneven, and several areas in the boreal zone will experience wetter winters and drier summers. This study uses the dynamic forest ecosystem model ForSAFE to estimate the combined effect of changes in temperature and precipitation on forest carbon stocks in Sweden. The model is used to simulate carbon stock changes in 544 productive forest sites from the Swedish National Forest Inventory. Forest carbon stocks under two alternative climate scenarios are compared to stocks under a hypothetical scenario of no climate change (baseline). Results show that lower water availability in the future can cause a significant reduction in tree carbon compared to a baseline scenario, particularly expressed in the southern and eastern parts of Sweden. In contrast, the north-western parts will experience an increase in tree carbon stocks. Results show also that summer precipitation is a better predictor of tree carbon reduction than annual precipitation. Finally, the change in soil carbon stock is less conspicuous than in tree carbon stock, showing no significant change in the north and a relatively small but consistent decline in the south. The study indicates that the prospect of higher water deficit caused by climate change cannot be ignored in future forest management planning.

In a future warmer climate, extremely dry, warm summers might become more common. Soil weathering is affected by temperature and precipitation, and climate change and droughts can therefore affect soil chemistry and plant nutrition. In this study, climate change and drought effects on soil weathering rates and release of Ca, Mg, K and Na were studied on seven forest sites across different climates in Sweden, using the dynamical model ForSAFE. Two climate scenarios were run, one medium severity climate change scenario from IPCC (A1B) and one scenario where a future drought period of 5 years was added, while everything else was equal to the first scenario. The model results show a large geographical variation of weathering rates for the sites, without any geographical gradient, despite the strong dependence of temperature on weathering and the strong gradient in temperature in Sweden. This is because soil texture and mineralogy have strong effects on weathering. The weathering rates have a pronounced seasonal dynamic. Weathering rates are low during winters and generally high, but variable, during summers, depending on soil moisture and temperature. According to the model runs, the future yearly average weathering rates will increase by 5 %–17 % per degree of warming. The relative increase is largest in the two southeastern sites, with low total weathering rates. At sites in southern Sweden, future weathering increase occurs throughout the year according to the modelling. In the north, the increase in weathering during winters is almost negligible, despite larger temperature increases than in other regions or seasons (5.9 ^∘C increase in winter in Högbränna; the yearly average temperature increase for all sites is 3.7 ^∘C), as the winter temperatures still will mostly be below zero. The drought scenario has the strongest effect in southern Sweden, where weathering during the later parts of the drought summers decreases to typical winter weathering rates. Soil texture and amount of gravel also influence how fast the weathering decreases during drought and how fast the soil rewets and reaches normal weathering rates after the drought. The coarsest of the modelled soils dries out and rewets quicker than the less coarse of the modelled soils. In the north, the soils do not dry out as much as in the south, despite the low precipitation, due to lower evapotranspiration, and in the northernmost site, weathering is not much affected. Yearly weathering during the drought years relative to the same years in the A1B scenario are between 78 % and 96 % for the sites. The study shows that it is crucial to take seasonal climate variations and soil texture into account when assessing the effects of a changed climate on weathering rates and plant nutrient availability.

A transition to a bio-based economy would entail change in coupled social–ecological systems. These systems are characterised by complexity, giving rise to potential unintended consequences and trade-offs caused by actions aiming to facilitate a transition process. Yet, many of the analyses to date have been focusing on single and predominantly technological aspects of the bio-based economy. The main contribution of our work is to the development of an integrated understanding of potential future transition pathways, with the present paper focusing specifically on terrestrial biological resources derived from the forestry sector in Sweden. Desired change processes identified include a transition to diversified forest management, a structural change in the forestry industry to enable high-value added production, and increased political support for the bio-based economy concept. Hindrances identified include the ability to demonstrate added values for end consumers of novel biomass applications, and uncertainty linked to a perceived high level of polarisation in the forestry debate. The results outline how these different processes are interrelated, allowing for the identification of high order leverage points and interventions to facilitate a transition to a bio-based economy.