title: Segregation of nitrogen use between ammonium and nitrate of ectomycorrhizas and beech trees.
abstract: Here, we characterized nitrogen (N) uptake of beech (Fagus sylvatica) and their associated ectomycorrhizal (EM) communities from NH4+and NO3-. We hypothesized that a proportional fraction of ectomycorrhizal N uptake is transferred to the host, thereby resulting in the same uptake patterns of plants and their associated mycorrhizal communities.15N uptake was studied under various field conditions after short-term and long-term exposure to a pulse of equimolar NH4+and NO3-concentrations, where one compound was replaced by15N. In native EM assemblages, long-term and short-term15N uptake from NH4+was higher than that from NO3-, regardless of season, water availability and site exposure, whereas in beech long-term15N uptake from NO3-was higher than that from NH4+. The transfer rates from the EM to beech were lower for15N from NH4+than from NO3-.15N content in EM was correlated with15N uptake of the host for15NH4+, but not for15NO3--derived N. These findings suggest stronger control of the EM assemblage on N provision to the host from NH4+than from NO3-. Different host and EM accumulation patterns for inorganic N will result in complementary resource use, which might be advantageous in forest ecosystems with limited N availability.
authors: Forstbotanik und Baumphysiologie, Georg-August Universität Göttingen, Büsgenweg 2, 37077, Göttingen, Germany.|Hochschule Geisenheim, Institut für Urbanen Gartenbau und Zierpflanzenforschung, Von-Lade-Str. 1, 65366, Geisenheim.
authors: Martin
authors: M
authors: Leberecht
authors: Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstrasse 19, 82467, Garmisch-Partenkirchen, Germany.
authors: Michael
authors: M
authors: Dannenmann
authors: Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Kreuzeckbahnstrasse 19, 82467, Garmisch-Partenkirchen, Germany.
authors: Javier
authors: J
authors: Tejedor
authors: Institute of Forest Science, Chair of Tree Physiology, University of Freiburg, Georges-Koehler-Allee 53/54, 79110, Freiburg, Germany.|Plant Physiology and Biochemistry Group, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
authors: Judy
authors: J
authors: Simon
authors: Institute of Forest Science, Chair of Tree Physiology, University of Freiburg, Georges-Koehler-Allee 53/54, 79110, Freiburg, Germany.
authors: Heinz
authors: H
authors: Rennenberg
authors: Forstbotanik und Baumphysiologie, Georg-August Universität Göttingen, Büsgenweg 2, 37077, Göttingen, Germany.
authors: Andrea
authors: A
authors: Polle
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D029964:Fagus / Q000378:metabolism* / Q000382:microbiology; D038821:Mycorrhizae / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D014867:Water / Q000378:metabolism
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D014867:Water
keywords: drought; ectomycorrhiza; temperate forest