Seasonal variability of total and easily leachable element contents in topsoils (0-5 cm) from eight catchments in the European Arctic (Finland, Norway and Russia)

azote capa arable del suelo carbon carbone carbono couche arable elements finland finlande finlandia frigid soils leaching lessivage du sol nitrogen noruega norway organic matter podzol podzoles podzols polar regions russian federation seasonal variation soil types suelo helado thawing tipos de suelos top soil type de sol