Correction factors for Holocene pollen diagrams (Facteurs de correction pour les diagrammes polliniques holocènes)

Studies of tree pollen found in moss humus and collected by pollen samplers in mixed forests have shown that the pollen productivity of various trees differs greatly Pinus, Quercus, Betula, and Alnus are high pollen producers and Fagus, Tilia and Fraxinus comparatively low pollen producers. Holocene pollen diagrams thus show a contorted picture of the true tree abundance. Calculated numerical correction factors can be applied successfully to recent pollen spectra, where tree abundance is known. Early Holocene pollen spectra were corrected in a similar way. The calculated area frequencies were compared with pollen concentations. Linear regression was found, and the differences in pollen productivity between Betula, Pinus, Alnus, Corylus, Ulmus and Tilia were nearly the same as in present-day forest. In this manner a better picture of Holocene forest composition can be obtained.La production pollinique des arbres varie selon les essences : très élevée chez Pinus, Quercus, Alnus et Betula, elle est par contre très faible chez Fagus, Tilia et Fraxinus. Des facteurs de correction établis d'après les spectres polliniques récents peuvent être appliques aux spectres polliniques du début de l'Holocène et permettre une reconstitution plus fidèle du couvert forestier .Andersen S. Th. Correction factors for Holocene pollen diagrams (Facteurs de correction pour les diagrammes polliniques holocènes). In: Bulletin de l'Association française pour l'étude du quaternaire, vol. 17, n°1-2, 1980. p. 80