[Variation of the mineral content of the needles of a spruce (Picea abies (L.) Karst.) grown in a CO2 enriched atmosphere. Study by X-ray microanalysis]

absorption de substances nutritives analyse de tissus atmosfera atmosphere belgique belgium calcio calcium carbon dioxide chambre de croissance contenido mineral dioxyde de carbone environmental factors experimentation facteur du milieu factores ambientales feuille fitotrones fosforo growth chambers hojas leaves microscopia microscopie microscopy mineral content nutrient uptake phosphore phosphorus picea abies potasio potassium tissue analysis