Stand structure modulates the long-term vulnerability of Pinus halepensis to climatic drought in a semiarid Mediterranean ecosystem
Article first published online: 30 DEC 2011
© 2011 Blackwell Publishing Ltd
Plant, Cell & Environment
Volume 35, Issue 6, pages 1026–1039, June 2012
How to Cite
MORENO-GUTIÉRREZ, C., BATTIPAGLIA, G., CHERUBINI, P., SAURER, M., NICOLÁS, E., CONTRERAS, S. and QUEREJETA, J. I. (2012), Stand structure modulates the long-term vulnerability of Pinus halepensis to climatic drought in a semiarid Mediterranean ecosystem. Plant, Cell & Environment, 35: 1026–1039. doi: 10.1111/j.1365-3040.2011.02469.x
- Issue published online: 22 APR 2012
- Article first published online: 30 DEC 2011
- Accepted manuscript online: 7 DEC 2011 07:28AM EST
- Received 23 September 2011; received in revised form 17 November 2011; accepted for publication 20 November 2011
- climate change;
- plant–climate interactions;
- stomatal conductance;
- water use efficiency
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.