Growth of Pinus pinea and Pinus halepensis as affected by dryness, marine spray and land use changes in a Mediterranean semiarid ecosystem

Abstract

Pine afforestations located on sand dunes, are among the most threatened coastal woodlands of semiarid western Mediterranean areas. In the recent time, dryness and land use changes seem to have caused a considerable degradation of these ecosystems. The marine spray affects their development as well. Our objective was to examine the possible effects of these ecological factors on tree-ring variation of Pinus pinea L. and Pinus halepensis Mill. We selected altogether 30 trees of both species from a sand dune stand located in the Guardamar Pine Woodland, Alicante, Spain. For both species we selected fi ve trees per each of three canopy damage levels and analysed four cores per tree. The results of dendrochronological analysis show that there exists a correlation between tree-ring widths and September-June precipitation and it is an inverse relationship between the growth-climate correlation and the degree of canopy damage. Moreover, trees showed an increased number of missing-rings during the 1990 ’s which was strongly related to severity of canopy damage due to marine spray. Synergistic effect of defoliation produced by the marine spray and dryer conditions due to limited water availability seem to have strong affect on variation of tree-ring widths.