CLIMATE CHANGE, TREE-RING WIDTH AND WOOD DENSITY OF PINES IN MEDITERRANEAN ENVIRONMENTS

During the second half of the 20th century, the Mediterranean area has experienced an increase in temperature, and a decrease in precipitation leading to a higher frequency of severe droughts. Consequently, widespread Mediterranean pine species suffered a shift in their climate-growth relationships that might lead to detrimental consequences. Wood features such as wood density are also affected by recent climatic changes producing an effect on wood structure and quality. Tree-ring anatomy was analyzed in three species (Pinus halepensis, P. pinaster and P. sylvestris), the three main pine species in Spain, in order to understand the relationships between tree-ring width and wood density as well as the influence of the climatic variations on these variables. Precipitation influenced tree radial growth and wood density for the three species, but at different times of the growth period. Mean and maximum density followed different patterns for the three species, decreasing with time in P. pinaster and increasing in P. halepensis and P. sylvestris. Growth and mean density trends were followed by a 5-year moving average with low variability in the three species. However, a high variability was observed in the inter-annual trends during the most recent years presumably related to climate. These climate-triggered modifications could adversely effect wood properties and wood quality.