Carbon dioxide neutrality of sustainably managed forests of Austria

Forests contribute to climate change mitigation by retaining carbon in their biomass, providing the renewable resource for wood-based products, bioenergy, and the substitution of materials with a bigger ecological footprint. Whether or not forest management is carbon neutral is a matter of discussion that is compromised by unclear terminology. It is claimed that unmanaged forests hold higher carbon stocks in the biomass and therefore contribute more to the mitigation of climate change. Particularly critical is the appraisal of bioenergy from wood. Based on Austrian data we demonstrate that forest management has been sustainable for at least several decades and that the business-as-usual management with a focus on timber production and bioenergy mainly as sidestream of timber processing does not introduce additional carbon dioxide (CO2) to the atmosphere, but removes it. With annual harvest rates consistently lower than the annual timber increment and a vital timber processing industry the forests and the wood products have been a sink of greenhouse gases that have compensated for on average 14 % of the Austrian greenhouse-gas (GHG) emissions between 1990 and 2022. We critically assess concepts that classify forest management operations as non-carbon-neutral and conclude that the narrative is only valid in regions with unsustainable forest management and deforestation. The storage of carbon in the biomass and in wood products, the generation of bioenergy mainly from a side stream of timber processing, and the substitution of non-wood products represent a consistent sink of carbon dioxide. We also conclude that frequently used baselines of unmanaged forests as comparison to managed forests are based on unfounded assumptions of forest ecosystem dynamics, insufficiently accounting for tree mortality and disturbances. We support the business-as-usual forest management as carbon neutral and recognize the need for active forest management to implement adaptive measures to successfully cope with climate change impacts, and to supply society with a renewable resource of small GHG footprint.