[en] The Swedish Nuclear Fuel and Waste Management Co (SKB) is currently investigating the Forsmark and Oskarshamn areas for possible localisation of a repository for spent nuclear fuel. Important components of the investigations are characterizations of the land surface ecosystems in the areas with respect to hydrological and biological processes, and their implications for the fate of radionuclide contaminants entering the biosphere from a shallow groundwater contamination. In this study, we simulate water balance and carbon turnover processes in forest ecosystems representative for the Forsmark and Oskarshamn areas for a 100-year period using the ecosystem process model CoupModel. The CoupModel describes the fluxes of water and matter in a one-dimensional soil-vegetation-atmosphere system, forced by time series of meteorological variables. The model has previously been parameterized for many of the vegetation systems that can be found in the Forsmark and Oskarshamn areas: spruce/pine forests, willow, grassland and different agricultural crops. This report presents a platform for further use of models like CoupModel for investigations of radionuclide turnover in the Forsmark and Oskarshamn area based on SKB data, including a data set of meteorological forcing variables for Forsmark 1970-2004, suitable for simulations of a 100-year period representing the present day climate, a hydrological parameterization of the CoupModel for simulations of the forest ecosystems in the Forsmark and Oskarshamn areas, and simulated carbon budgets and process descriptions for Forsmark that correspond to a possible steady state of the soil storage of the forest ecosystem