, Volume 13, Issue 7, pp 978–991 | Cite as

Drought-Induced Multifactor Decline of Scots Pine in the Pyrenees and Potential Vegetation Change by the Expansion of Co-occurring Oak Species

  • L. Galiano
  • J. Martínez-Vilalta
  • F. Lloret


Episodes of drought-induced tree dieback have been recently observed in many forest areas of the world, particularly at the dry edge of species distributions. Under climate change, those effects could signal potential vegetation shifts occurring over large geographical areas, with major impacts on ecosystem form and function. In this article, we studied the effect of a single drought episode, occurred which in summer 2005, on a Scots pine population in central Pyrenees (NE Spain). Our main objective was to study the environmental correlates of forest decline and vegetation change at the plot level. General and generalized linear models were used to study the relationship between canopy defoliation, mortality and recruitment, and plot characteristics. A drought-driven multifactor dieback was observed in the study forest. Defoliation and mortality were associated with the local level of drought stress estimated at each plot. In addition, stand structure, soil properties, and mistletoe infection were also associated with the observed pattern of defoliation, presumably acting as long-term predisposing factors. Recruitment of Scots pine was low in all plots. In contrast, we observed abundant recruitment of other tree species, mostly Quercus ilex and Q. humilis, particularly in plots where Scots pine showed high defoliation and mortality. These results suggest that an altitudinal upwards migration of Quercus species, mediated by the dieback of the currently dominant species, may take place in the studied slopes. Many rear-edge populations of Scots pine sheltered in the mountain environments of the Iberian Peninsula could be at risk under future climate scenarios.

Key words

drought scots pine (Pinus sylvestris L.canopy defoliation mortality recruitment summer water availability stand structure soil properties mistletoe 



We would like to thank the Catalan Forest Service, and especially Carles Fañanàs Aguilera, for facilitating our field work and for their generous comments. We are also indebted to all the undergraduate students (Miriam, Albert, Nil, Joan) that were involved in this study. We appreciate helpful comments from Bernat Claramunt, Javier Retana, and Jofre Carnicer on the earlier version of the manuscript. This study was supported by the Spanish Ministry of Education and Sciences via competitive projects CGL2006-01293, CGL2007-60120, and CSD2008-0004. LG was supported by an FPI scholarship from the Spanish Ministry of Education and Sciences.

Supplementary material

10021_2010_9368_MOESM1_ESM.tif (8.7 mb)
Supplementary Figure s1 Size (DBH) class distribution of the studied Scots pine population. N = 1002 (Tif 8940 kb)
10021_2010_9368_MOESM2_ESM.tif (8.7 mb)
Supplementary Figure s2 Average seedling abundance of all species found in the study at the plot level (Tif 8904 kb)


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© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.CREAF/Unidad de EcologíaUniversidad Autónoma de BarcelonaBellaterraSpain

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