Response of magnesium-deficient saplings in a young, open stand of Picea abies (L.) Karst. to elevated soil magnesium, nitrogen and carbon

alemania allemagne arbre forestier azote carbon carbone carbono chimie du sol deficiency diseases feuille foliage forest pathology forest trees germany hojas leaves magnesio magnesium maladie de carence nitrogen nutrient deficiencies nutrition des plantes picea abies plant nutrition pollution du sol simulation models soil chemistry soil pollution