Parameter Variable Unit Description Critical load of acidity CLmaxS

National maps produced In response to the call for data of October 2005, a new data set of critical loads for acidity and eutrophication was provided. The critical loads (CLs) were updated for forested lands of European Russia on a 5x5 km2 grid. Data processing included combining soil and land use data with GIS layers such as temperature, precipitation amounts, base cations depositions and others. The following maps were produced: • maximum critical loads of sulphur, • maximum critical loads of nitrogen, • minimum critical loads of nitrogen, • critical loads of nutrient nitrogen. Calculation methods In the previous submissions, critical loads of S and N for terrestrial ecosystems of European Russia have been calculated using modified steady-state mass balance equations (Bashkin et al., 1995, 1999). A percentage of coniferous/deciduous forests and arable lands were used to describe a spatial distribution of main input data and to calculate CLs in 50×50 km2 grids. The Russian NFC now updated both the database and calculation methods. In general, critical loads were computed in accordance with the methods summarized in the Mapping Manual (UBA, 2004). The basic ecosystem map for calculating and mapping was produced by overlaying several maps; it consists of 31,043 units. A summary of the variables used and methods/approaches applied is given i