[EN] Due to their diversity and dominance in environmentally harsh sites, Mediterranean dwarf shrubs are a valuable tool to understand the consequences of climatic variability on radial growth in woody plants. We evaluate the dendrochronological potential of three Mediterranean dwarf shrubs versus three coexisting tree species inhabiting cold- (Hormathophylla spinosa vs. Pinus sylvestris), mesic- (Ononis fruticosa vs. Abies alba), and xeric sites (Linum suffruticosum vs. Pinus halepensis). Cross-sectional wood sections of the three shrub species and cores in the case of trees were visually cross-dated and ring-widths were measured and converted into residual growth indices. We used linear mixed-effects models to assess how growth indices respond to local factors and climatic variables. The radial growth of the three dwarf shrub species was more asynchronous, i. e., ring-width series differed among conspecific individuals, than that of coexisting tree species. Growth asynchrony was higher for H. spinosa than for O. fruticosa and L. suffruticosum. Similarly, the ring-width series of O. fruticosa and L. suffruticosum was strongly correlated with that of coexisting tree species, while growth series of H. spinosa and P. sylvestris was not related at all. The growth of the three dwarf shrub species was influenced by the regional climatic conditions, but to a lesser degree than coexisting tree species. The highest responsiveness of growth to climate was observed in Mediterranean dwarf shrubs from xeric sites. However, local conditions are also major drivers of growth in Mediterranean dwarf shrubs as indicated by the stronger asynchrony in ring formation of these species as compared with coexisting trees, particularly in cold sites. © 2012 Springer Science+Business Media B.V.

Antonio Gazol is supported by the ERMOS programme (co-founded by Marie Curie Actions), Grant number 14. This work has been supported by research projects CGL2008-04847-C02-01/BOS and CGL2011-26654 financed by the Spanish Commission of Science and Technology and FEDER. J. Julio Camarero acknowledges the support of ARAID. We thank G. Sanguesa and H. A. Chaparro for their brave help in the field, and M.C. Sancho for her advice in the laboratory

Peer Reviewed