Plant Ecology

, 169:131

Hydraulic properties of Pinus halepensis, Pinus pinea and Tetraclinis articulata in a dune ecosystem of Eastern Spain

Authors

  • Imma Oliveras
    • CREAF, Facultat de CiènciesUniversitat Autònoma de Barcelona
    • CREAF, Facultat de CiènciesUniversitat Autònoma de Barcelona
  • Teresa Jimenez-Ortiz
    • Departament d'EcologiaUniversitat d'Alacant
  • Maria José Lledó
    • Departament d'EcologiaUniversitat d'Alacant
  • Antoni Escarré
    • Departament d'EcologiaUniversitat d'Alacant
  • Josep Piñol
    • CREAF, Facultat de CiènciesUniversitat Autònoma de Barcelona
Article

DOI: 10.1023/A:1026223516580

Cite this article as:
Oliveras, I., Martínez-Vilalta, J., Jimenez-Ortiz, T. et al. Plant Ecology (2003) 169: 131. doi:10.1023/A:1026223516580

Abstract

The hydraulic properties of Pinus pinea, Pinus halepensis and Tetraclinis articulata were studied in a coastal dune area from Eastern Spain. The measured variables include vulnerability to xylem embolism (vulnerability curves), hydraulic conductivity and carbon isotopic discrimination in leaves. Leaf water potentials were also monitored in the three studied populations during an extremely dry period. Our results showed that roots had always wider vessels and higher hydraulic conductivity than branches. Roots were also more vulnerable to xylem embolism and operated closer to their hydraulic limit (i.e., with narrower safety margins). Although it was not quantified, extensive root mortality was observed in the two pines during the study period, in agreement with the high values of xylem embolism (> 75%) predicted from vulnerability curves and the water potentials measured in the field. T. articulata was much more resistant to embolism than P. pinea and P. halepensis. Since T. articulata experienced also lower water potentials, safety margins from hydraulic failure were only slightly wider in this species than in the pines. Combining species and tissues, high resistance to xylem embolism was associated with low hydraulic conductivity and with high wood density. Both relationships imply a cost of having a resistant xylem. The study outlined very different water-use strategies for T. articulata and the pines. Whereas T. articulata had a conservative strategy that relied on the low vulnerability of its conducting system to drought-induced xylem embolism, the two pines showed regulatory mechanisms at different levels (i.e., embolism, root demography) that constrained the absorption of water when it became scarce.

Conifers Drought Hydraulic conductivity Hydraulic limits Xylem embolism

Copyright information

© Kluwer Academic Publishers 2003