1. Department of Geology and Geochemistry, Stockholm University, S-106 91 Stockholm, Sweden; Norwegian Forest Research Institute, Högskoleveien 12, N-1432 Ås, Norway; Department of Soil and Water Sciences, Agricultural University of Norway, P.O. Box 5028, N-1432 Ås, Norway; IVL, Swedish Environmental Research Institute, Box 470 86, S-402 58 Göteborg, Sweden; Department of Forest Ecology, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden; and Climate Impact Research Centre, Department of...