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Aim The Mediterranean Basin is considered to be a climate-change hotspot, for which rising temperatures and associated aridification have been forecast. Such trends could affect the performance and growth of conifers in these drought-prone areas. We evaluated whether radial growth and wood density can act as proxy measures of precipitation and drought in a Mediterranean conifer. Location Iberian Juniperus thurifera forests in northern and eastern Spain. Methods We sampled 10 stands encompassing J. thurifera's distributional area. We related four annually resolved tree-ring variables (earlywood and latewood width, and maximum and minimum wood density) to climatic factors (temperature, precipitation and drought index) for the period 1951-2000. We then analysed the spatial and temporal patterns of those associations. Results Of all the four tree-ring variables analysed, minimum wood density presented the strongest response to climate. Higher values of minimum wood density were related to drier spring conditions, particularly in the most xeric sites, confirming that a drought-induced reduction in the radial expansion of tracheids increases earlywood density. Main conclusions Minimum wood density is a biogeographically meaningful proxy of spring water availability for the Mediterranean conifer J. thurifera. [ABSTRACT FROM AUTHOR]

•Seasonal radial-increment and xylogenesis data can help to elucidate how climate modulates wood formation in conifers. Few xylogenesis studies have assessed how plastic xylogenesis is in sympatric conifer species from continental Mediterranean areas, where low winter temperatures and summer drought constrain growth. •Here, we analysed intra-annual patterns of secondary growth in sympatric conifer species ( Juniperus thurifera, Pinus halepensis and Pinus sylvestris). Two field sites (xeric and mesic) were evaluated using dendrometers, microcores and climatic data. •A bimodal pattern of xylogenesis characterized by spring and autumn precipitation and subsequent cambial reactivation was detected in J. thurifera at both study sites and in P. halepensis at the xeric site, but was absent in P. sylvestris where growth was largely controlled by day length. In the xeric site J. thurifera exhibited an increased response to water availability in autumn relative to P. halepensis and summer cambial suppression was more marked in J. thurifera than in P. halepensis. • Juniperus thurifera exhibited increased plasticity in its xylogenesis pattern compared with sympatric pines, enabling this species to occupy sites with more variable climatic conditions. The plastic xylogenesis patterns of junipers in drought-stressed areas may also provide them with a competitive advantage against co-occurring pines. [ABSTRACT FROM AUTHOR]