Assessing Mg and Ca depletion from broadleaf forest soils and potential causes - A case study in the Morvan Mountains

► Mg was depleted from the soil over the 1974-2001 period. ► S and Ca atmospheric deposition has decreased since 1990 in the Morvan Mountains. ► Mg and Ca depletion occurs still due to an important sulphate desorption flux. ► Mg, Ca and K budgets were negative during the 2003-2008 period. ► Tree nutrition did not seem affected by small and decreasing nutrient pools.