Assessing trade-offs between carbon sequestration and timber production within a framework of multi-purpose forestry in Austria

Numerous studies have analyzed the carbon sequestration potential of forests and forest management. However, most studies either focused on national and supra-national scales or on the project level in the context of the flexible mechanisms of the Kyoto Protocol. Few studies are available which analyze the effects of alternative silvicultural strategies on carbon sequestration, timber production and other forest services and functions at the operational level of the forest management unit (FMU). The present study investigates effects of three alternative management strategies for secondary Norway spruce forests (Picea abies (L.) Karst.) (Norway spruce age class forestry; continuous cover forestry; conversion to mixed broadleaved forests) and an unmanaged control variant on C sequestration in situ, in wood products and through bioenergy production at the level of a private FMU in Austria, and analyses the interrelationships with timber production and key indicators of biodiversity. The hybrid patch model PICUS v1.4 and a wood products model are employed to simulate forest ecosystem development, timber production, carbon storage in the forest and in wood product pools. Results show that in situ C sequestration is sensitive to forest management with the highest amount of carbon stored in the unmanaged strategy, followed by the continuous cover regime. All three management strategies store substantial quantities of C in the wood products pool. Considering alternative biomass utilization focused on bioenergy production, substantial C offsets could be generated from potential substitution of fossil fuels. Opportunity cost estimates for C sequestration reveal that C sequestration through forest management can be a cost efficient way to reduce atmospheric CO₂, but the achievable quantities are limited due to biological limitations and societal constraints. The study emphasizes the importance of developing sustainable forest management strategies that serve the multiple demands on forests in the future.