title: Douglas-fir seedlings exhibit metabolic responses to increased temperature and atmospheric drought.
abstract: In the future, periods of strongly increased temperature in concert with drought (heat waves) will have potentially detrimental effects on trees and forests in Central Europe. Norway spruce might be at risk in the future climate of Central Europe. However, Douglas-fir is often discussed as an alternative for the drought and heat sensitive Norway spruce, because some provenances are considered to be well adapted to drier and warmer conditions. In this study, we identified the physiological and growth responses of seedlings from two different Douglas-fir provenances to increased temperature and atmospheric drought during a period of 92 days. We analysed (i) plant biomass, (ii) carbon stable isotope composition as an indicator for time integrated intrinsic water use efficiency, (iii) apparent respiratory carbon isotope fractionation as well as (iv) the profile of polar low molecular metabolites. Plant biomass was only slightly affected by increased temperatures and atmospheric drought but the more negative apparent respiratory fractionation indicated a temperature-dependent decrease in the commitment of substrate to the tricarboxylic acid cycle. The metabolite profile revealed that the simulated heat wave induced a switch in stress protecting compounds from proline to polyols. We conclude that metabolic acclimation successfully contributes to maintain functioning and physiological activity in seedlings of both Douglas-fir provenances under conditions that are expected during heat waves (i.e. elevated temperatures and atmospheric drought). Douglas-fir might be a potentially important tree species for forestry in Central Europe under changing climatic conditions.
authors.affiliation: Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany.
authors.forename: Kirstin
authors.initials: K
authors.lastname: Jansen
authors.affiliation: Institute for Forest Botany and Tree Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany; Sichuan Province Key Laboratory of Ecological Security and Protection, Mianyang Normal University, Mianyang, China.
authors.forename: Baoguo
authors.initials: B
authors.lastname: Du
authors.affiliation: Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Kayler
authors.affiliation: Laboratory of Atmospheric Chemistry, Stable Isotopes and Ecosystem Fluxes, Paul Scherrer Institute (PSI), Villigen, Switzerland.
authors.forename: Rolf
authors.initials: R
authors.lastname: Siegwolf
authors.affiliation: Department of Biology, University of Toronto, Mississauga, Ontario, Canada.
authors.forename: Ingo
authors.initials: I
authors.lastname: Ensminger
authors.affiliation: Institute for Forest Botany and Tree Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Rennenberg
authors.affiliation: Core Facility Metabolomics, Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs University Freiburg, Freiburg, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kammerer
authors.affiliation: Core Facility Metabolomics, Center for Biological Systems Analysis (ZBSA), Albert-Ludwigs University Freiburg, Freiburg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Jaeger
authors.affiliation: Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland.
authors.forename: Marcus
authors.initials: M
authors.lastname: Schaub
authors.affiliation: Institute for Forest Botany and Tree Physiology, Albert-Ludwigs University Freiburg, Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kreuzwieser
authors.affiliation: Institute for Landscape Biogeochemistry, Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland; Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany.
authors.forename: Arthur
authors.initials: A
authors.lastname: Gessler
mesh_terms: D000064:Acclimatization; D018533:Biomass; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism; D002980:Climate; D055864:Droughts; D028224:Pseudotsuga / Q000254:growth & development / Q000502:physiology*; D036226:Seedlings / Q000254:growth & development / Q000502:physiology*; D013696:Temperature; D014867:Water / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D014867:Water