Turnover and distribution of fertilizer nitrogen in three coniferous ecosystems in central Sweden

absorption de substances nutritives calcium nitrate coniferous forests fertilizantes nitrogenados forest soils leaching nitrate de chaux nitrato de calcio nitrogen fertilizers nitrogen metabolism nutrient transport nutrient uptake picea abies pinus sylvestris procesos de transporte en el suelo radioisotopes radioisotopos soil transport processes suelo forestal technique des traceurs tracer techniques transport dans le sol transport des substances nutritives transporte de nutrientes urea uree