Stand structure modulates the long-term vulnerability of Pinus halepensis to climatic drought in a semiarid Mediterranean ecosystem

Authors

  • CRISTINA MORENO-GUTIÉRREZ,

    Corresponding author
    1. Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, PO Box 164, 30100 Murcia, Spain
    2. WSL Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland
      C. Moreno-Gutiérrez. Fax: +34 968396213; e-mail: cmorenogutierrez@gmail.com
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  • GIOVANNA BATTIPAGLIA,

    1. Paleoenvironments and Chronoecology (PALECO EPHE), Ecole Pratique des Hautes Etudes, Institut de Botanique, 163 rue Broussonet, 34090 Montpellier, France
    2. Centre for Bio-Archeology and Ecology (UMR5059), Institut de Botanique, University of Montpellier 2, 34090 Montpellier, France
    3. WSL Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland
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  • PAOLO CHERUBINI,

    1. WSL Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland
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  • MATTHIAS SAURER,

    1. Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
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  • EMILIO NICOLÁS,

    1. Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, PO Box 164, 30100 Murcia, Spain
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  • SERGIO CONTRERAS,

    1. Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, PO Box 164, 30100 Murcia, Spain
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  • JOSÉ IGNACIO QUEREJETA

    1. Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, PO Box 164, 30100 Murcia, Spain
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C. Moreno-Gutiérrez. Fax: +34 968396213; e-mail: cmorenogutierrez@gmail.com

ABSTRACT

We investigated whether stand structure modulates the long-term physiological performance and growth of Pinus halepensis Mill. in a semiarid Mediterranean ecosystem. Tree radial growth and carbon and oxygen stable isotope composition of latewood (δ13CLW and δ18OLW, respectively) from 1967 to 2007 were measured in P. halepensis trees from two sharply contrasting stand types: open woodlands with widely scattered trees versus dense afforested stands.

In both stand types, tree radial growth, δ13CLW and δ18OLW were strongly correlated with annual rainfall, thus indicating that tree performance in this semiarid environment is largely determined by inter-annual changes in water availability.

However, trees in dense afforested stands showed consistently higher δ18OLW and similar δ13CLW values compared with those in neighbouring open woodlands, indicating lower stomatal conductance and photosynthesis rates in the former, but little difference in water use efficiency between stand types. Trees in dense afforested stands were more water stressed and showed lower radial growth, overall suggesting greater vulnerability to drought and climate aridification compared with trees in open woodlands.

In this semiarid ecosystem, the negative impacts of intense inter-tree competition for water on P. halepensis performance clearly outweigh potential benefits derived from enhanced infiltration and reduced run-off losses in dense afforested stands.

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