An optimization approach for balancing global wood demand and environmental goals on management strategies in Swedish forests

Abstract

The transition towards the bio-based economy in the future increases the demand for raw materials from the forests. This will increase the extraction of wood from the forests but may adversely affect its biodiversity and other ecosystem services (ESS). The growth rate of most tree species in Sweden is predicted to increase because of changing climate. It will however be counterbalanced by an increased risk of damage due to extreme weather events such as storms. Therefore, it is necessary to develop adaptive management measures that exploit the benefits of climate change while minimizing the damages on growing stock, ESS and biodiversity resulting from its risks. It is further important to consider the trends in the global development for studying the future trends of production and nature conservation in Sweden . The demand for wood varies among the global development scenarios and greenhouse gas emission pathways. The aims of this study are: (i) to identify the impacts of climate change, EU forest policies and associated wood demand on Swedish forests, (ii) how the combination of different scenarios of EU forest policies and climate affects the harvest levels, carbon sequestration and future occurrence of a set of forest-dwelling species in Sweden and (iii) to formulate optimal combinations of different management regimes for sustainably achieving the demand for different wood assortments and environmental goals in Sweden as stipulated in EU and national forest policy statements under changing climatic conditions. In this study the demand for different wood assortments in Sweden will be simulated assuming different global and EU policy scenarios using the GLOBIOM model. The three policy scenarios are baseline, bioenergy and global bioenergy. In the baseline scenario, the increase in global demand for wood stabilizes by 2020 whereas in others the increase in wood demand stabilizes only after 2050. In the global bioenergy scenario, mitigation measures are implemented globally resulting in higher wood demand in comparison to the bioenergy scenario where mitigation measures are confined only to EU. Assuming the different demand for wood assortments, we will propose adaptive management measures like delaying final felling, avoiding thinning and speeding up final felling, green tree retention, continuous cover forestry and unmanaged forest along with a current management scenario. The simulations of the Swedish forest landscape with different adaptive management regimes will be performed using the Heureka model. Optimization will be done for maximizing various objectives like net present value, carbon sequestration and biodiversity. Biodiversity will be accounted for in the form of different species distribution models. The time period of the simulations will be from 2010 to 2100. Two future climate scenarios, a business as usual scenario (RCP8.5) and an optimistic scenario (RCP4.5) are also considered in this study.