Estimating weathering rates of Swedish forest soils in different scales, using the PROFILE model and affiliated databases

Weathering rates of forest soils are important for estimating nutrient sustainability and critical loads of acidity.Such rates can be estimated with the PROFILE model using input data about soil properties, climate, and forest species. PROFILE has been extensively tested on field data in the past, and found to perform well under a wide range of conditions. A high resolution soil geochemistry database now available in Sweden implies new possibilities for regional assessments of weathering rates as well as assistance to local assessments. Regional weathering rates are required by decision makers as inputs in forest sustainability assessments and critical load calculations, whereas calculations on a local level can provide help for the forest owners to adjust their forestry to the nutrient availability of the soil in order to inhibit long-term nutrient deficiency. In this paper weathering calculations for different scales, using the PROFILE model, are demonstrated and discussed. The high resolution geochemical database of Sweden is a good basis for PROFILE weathering calculations in different scales. The required resolution of complementing input data depends on the requested accuracy in the output, which is closely connected to the aim of the calculations.