LAUSR

Abstract Achieving a global forest transition, that is a shift from deforestation to reforestation, is important for climate-change mitigation. Forest transitions are enabled by socioecological processes, including land displacement, agricultural intensification and woodfuel substitution for other energy, but their respective contributions remain poorly understood. Here, by means of a scenario approach we quantify the importance of enabling conditions of the forest transition in Austria between 1830 and 1910 and their overall emissions implications, including the forest carbon sink potential in the hypothetical absence of wood use. We combine historical databases on land use, biomass production and energy use and an empirical dynamic forest growth model to develop five hypothetical counterfactual scenarios. The scenarios assume food and energy consumption in the absence of woodfuel substitution, food imports and three variations of agricultural intensification and assess effects on forest change and carbon balances. We find that the absence of any of the enabling conditions would have completely depleted forest biomass by 1910. Livestock efficiency gains and woodfuel substitution, two rarely discussed drivers of forest change, were equally important as yield increase and land displacement. The cumulative forest sink potential in the absence of any wood extraction throughout the period was found to be about twice the forest carbon stock in 1830. All counterfactual scenarios led to increasing overall emissions, “no woodfuel substitution” being closest to the historical trend. Our work lays the ground for a new typology of forest transitions according to the socioecological processes that enable them.