Altitudinal Gradients and Forest Response:
Climate, Hydrology and Isotope Variability
of a Mediterranean Ecosystem

Abstract:

The island of Corsica, France, poses a unique study area. The fourth largest island of the Mediterranean Sea is dominated by a north-south oriented mountain range that peaks at 2700 metres. In previous studies Pinus nigra subsp. laricio proved to be a reliable source of robust ringwidth chronologies at tree line sites. But the characteristics of tree growth in other parts of the island are yet to be unveiled. Due to the distribution of two pine species (Pinus pinaster in lower areas and Pinus nigra subsp. laricio in higher regions) it is possible to cover the altitudinal range of the island from alpine environments to Mediterranean coasts. By means of tree-ring analysis, the relation between tree age and temporal growth changes was evaluated via growth trajectories for pines in different age classes at various sites across the island, ranging from 1600m asl to sea level. We hypothesize that tree growth in high altitudes is limited by temperature whereas the growth limiting factor in the lowlands is summer drought. First analyses on differences and similarities in growth trajectories depending on altitude, species, and east or west slope of the mountain range will be presented.