Climate increases regional tree‐growth variability in Iberian pine forests

摘要: Tree populations located at the geographical distribution limit of species may provide valuable information about tree-growth response to changes on climatic conditions. We established nine Pinus nigra ,1 2P. sylvestris and 17 P. uncinata tree-ring width chronologies along eastern northern Iberian Peninsula, where these are found edge their natural range. Tree-growth variability was analyzed using principal component analysis (PCA) for period 1885–1992. Despite diversity species, habitats regimes, a common macroclimatic signal expressed by first (PC1) found. Moreover, considering PC1 scores as regional chronology, significant relations were with Spanish meteorological data. The shared variance held tree chronologies, frequency narrow rings interannual growth (sensitivity) increased markedly during studied period. This shows an enhancement synchrony among forests indicating that climate might have become more limiting growth. Noticeably, upward abrupt shift in end half 20th century detected. On other hand, moving-interval functions showed change growth–climate relationships same relationship between late summer/autumn temperatures year before (August– September, negative correlation, November, positive correlation) became stronger. Hence, water stress increase summer previous could be linked larger sites, suggesting driving pattern changes. agrees trend temperature observed months. higher occurrence extreme years sensitivity second agreement increment precipitation growing Precipitation positively related variability, but negatively radial In conclusion, detected since mid-20th stress. These temporal trends warmer conditions variability.