Lake sediments reveal links between functional fire types and socio-ecological history in northern Poland

Abstract Fire has played an important role in shaping landscapes through long-term human activity, influencing vegetation, land use, and ecosystem processes. This study reconstructs fire history over the last ~ 800 years using varved lake sediments from Lake Priamy in northern Poland. Micro- and macrocharcoal records are analyzed alongside sedimentological, palynological, chronological, and historical data to examine how different forms of anthropogenic fire are preserved in lacustrine archives. The results indicate that charcoal size fractions reflect different spatial scales and contexts of fire use. Microcharcoal mainly records changes operating at the landscape scale, including forest clearance, settlement development, and periods of heightened disturbance, some of which coincide with historically documented military events. Macrocharcoal, in contrast, reflects local fire activity associated with routine forest use, such as tar production, charcoal making, and woodland management. The sediment record reveals continuous human presence in the area, phases of increasing agricultural activity, intensified land use during the nineteenth century, and clear signals related to twentieth-century warfare, followed by a decline in cultivation and increasing afforestation. Consistency between independent proxy data and historical sources supports the robustness of the chronological framework and allows for a detailed interpretation of charcoal signals as indicators of human-driven environmental change.