Dendroclimatological Study of Pinus Sylvestris L. in Southern Catalonia (Spain)

Abstract

Two modem tree-ring width chronologies of Pinus sylvestris L. have been established in an area near the southern limit of the species' distribution. Trees were sampled in the South of Catalonia in northeastern Spain where Mediterranean climatic conditions are of primary influence. To better understand climate ring-width relationships, tree-ring index series have been studied in relation to local climate. Ring-widths are strongly related to low precipitation at the beginning of the growing season in March, in June of the current growth year, and in September prior to tree-ring growth. High temperatures mainly affect growth in summer during the growing season and in autumn of the year prior to growth. During the winter, mainly in December, mean monthly temperatures show a significant positive correlation with growth. Major factors controlling the southern distribution of P. sylvestris may be related not only to water stress in summer but also to the amount of precipitation at the beginning of the growing season and in autumn, even in mild winters.