Paleolimnological reconstruction of forest fire induced changes in lake biogeochemistry (Lac Francis, Abitibi, Quebec, Canada)

Abstract

Biogeochemical effects of fire events were analysed in a small humic kettle lake, Lac Francis (claybelt area, Abitibi, northwestern Quebec), using diatom-based quantitative inference models developed to reconstruct past pH, total phosphorus, and dissolved organic carbon in Abitibi lakes. Diatom-inferred changes in lake geochemistry in four historical fire events were examined and the results showed that, on average, total phosphorus concentrations increased significantly (up to twofold) during fire events. In contrast, dissolved organic carbon concentrations and pH were relatively unaffected by the fires.