Forest@ (Mar 2008)
Ecophysiological responses of Pinus leucodermis at high elevation in the Mediterranean area
Abstract
Pinus leucodermis Antoine (= Pinus heldreichii var. leucodermis) is a species of the Balkan flora which in Italy grows in a small area between the Regions of Basilicata and Calabria, in the Pollino National Park. A relict of the oro-Mediterranean Tertiary forests, it is found from the lower vegetation belt, where it is mixed with evergreen sclerophyllous vegetation, up to the alpine vegetation belt beyond the closed formations of Fagus sylvatica, where it makes up stands with very old, isolated and big trees growing in open spaces between rocks. The ecophysiological and dendrochronolgy features of the P. leucodermis stands growing on the west slope of Serra di Crispo (Monte Pollino), between 1800 and 2000 m a.s.l., have been studied during recent years and some of the results are presented in this work. Ecophysiological measurements in situ show that reduced atmospheric vapour pressure deficit conditions, due to humid currents from the western Tyrrhenian Sea, allow the trees to escape from summer drought. When day summer weather conditions are optimal P. leucodermis exhibits a remarkable photosynthetic activity and adaptation to high irradiance. The tree ring width chronology documents a marked reduction of radial growth from 1950 to 1985, followed by a strong recovery, still continuing. In the same period differences between the annual minimum and maximum temperatures tend to increase. Anthropic and grazing pressure is reduced markedly after the institution of the National Park of Pollino.
