Nitrogen balance of a boreal Scots pine forest J. F. J. Korhonen, M. Pihlatie, J. Pumpanen, H. Aaltonen, P. Hari, J. Levula, A.-J. Kieloaho, E. Nikinmaa, T. Vesala, and H. Ilvesniemi Department of Physics, P.O. Box 48, 00 014, University of Helsinki, Finland Department of Forest Sciences, P.O. Box 27, 00 014, University of Helsinki, Finland Hyytiälä Forestry Field station, Hyytiäläntie 124, 35 ...