Fig. 3: Driftwood carbon storage model with agent-perspective.

A Circumpolar boreal forest zone with large river systems, and the extent of burnt boreal forest between 2002 and 2020 that amounts to circa 1,835,00 km² (red areas)^42,43. B Least-cost analysis of a boreal forest patch with suitable timber harvesting parameters and optimal driftwood transportation conditions along the closest river to the nearest ocean⁵⁴. Floating time is calculated as average downstream river run-off velocity and depending on rafting style and wood amount. An ecological buffer zone has been included around the nearest administrative centre from which labour and logistics are directed. The simplified model design includes an agent-perspective⁵⁵, in which the ability for the exogenous (e.g., harvesting for wood products and wood vaulting, and maintenance for carbon offsetting) and endogenous (e.g., cultural, herding, etc) demand for forest services to be met by spatial production depends on factors such as forest productivity, land ownership, infrastructure, human resources and the decisions of modelled agents, informed by their values, objectives and perceptions of future monetary and non-monetary value of land. C Pictures of natural driftwood erosion, tree tipping and driftwood rafting, as well as Indigenous people at the Indigirka river in northeastern Siberia (all taken by Ulf Büntgen in July 2016).