RECONSTRUCTING HISTORIC ATMOSPHERIC DEPOSITION AND NUTRIENT-UPTAKE FROM PRESENT-DAY VALUES USING MAKEDEP

A model, MAKEDEP, was developed for reconstructing historic atmospheri c deposition and nutrient uptake for forests using present day values. Deposition is reconstructed by separation of wet deposition and throu ghfall into five different categories. Dry deposition is assumed to de pend linearly on needle biomass. Non-marine deposition is scaled using general European emission and deposition trends for sulphur, nitrate and ammonia. Historic nutrient uptake is reconstructed using current b iomass and nutrient content, a logistic forest growth curve and inform ation on historic land use.