EFFET DES FACTEURS STATIONNELS SUR LA CROISSANCE RADIALE ET LA RÉPONSE DU PIN D’ALEP AU CLIMAT DANS LE MASSIF DE L’OUARSENIS, ALGÉRIE

The relationships between climate and radial growth from 1967 to 2010 in nine Aleppo pine stands in the Ouarsenis range (north-western Algeria) were stud- ied according to station-specific factors (substrate, altitude, exposure and age of the trees) using dendro-chronological methods, with an analysis of interannual variations in the thickness of growth rings. A retrospective analysis of radial growth showed high interannual vari- ability in growth ring thickness within the same stand. The statistical parameters calculated showed highly variable radial growth between the different stands, which was related to station-specific factors and to tree age. Average growth ring thickness and persistence declined with the age of the trees. Average sen- sitivity to climate tended to be greater  in trees growing on sandstone or schist substrates than on limestone. Our analy- sis of the relationships between climate and growth rings shows that the Aleppo pine is responsive to precipitation before or during the formation of growth rings. Higher temperatures, especially when they reach their maximum, have a nega- tive effect on radial growth. The relation- ships between Aleppo pines and climatic conditions are modulated by station-spe- cific factors, especially the substrate. The most responsive stands tend to be growing on a sandstone substrate. These results provide a useful description to help understand the ecological flexibility of the Aleppo pine and how it responds to climate change, with a view to propos- ing better ways of protecting pine forests that have been under threat for several decades.