Das Projekt "The Role of Root Exudates in Aluminium Tolerance of Norway Spruce" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft.This project aims at the role of chelating organic exudates from non-mycorrhizal long-roots and ectomycorrhizal lateral roots in Al tolerance of coniferous trees. A laboratory study is performed with Norway spruce seedlings as model system. Non-mycorrhizal and ectomycorrhizal seedlings are treated with solutions in which pH and total concentrations of Al and Ca are varied. Organic root exudates are analyzed for their composition with emphasis on low-molecular weight organic acids and phenolic compounds. The composition of root exudates and the occurrence of organically complexed Al are compared with concurrent changes in element uptake, and in root and shoot morphology. Leading Questions: Do chelating organic exudates play a role in the aluminum tolerance of coniferous trees?