Do the Fagus sylvatica forests of the Pieria mountains (Northern Greece) form an altitudinal belt, or are they extrazonal? A study of the transition between temperate and submediterranean forests in Northern Greece

Exposition, elevation, and soil water storage capacity represent major fact ors of forest vegetation differences at the north-exposed, shaded slopes of the valley of the Mavroneri creek, Pieria mountains, Northern Greece (Tab. 12). Above ca. 1250 m a.s.l., red beech (Fagus sylvatica) represents the d ominant canopy species in a species-poor, high-montane Orthilio-Fagetum whi ch can be further subdivided into four subassociations. Below ca. 1250 m a. s.l., there exists a transition towards montane beech forests of the Lathyr o-Fagetum. Within the Lathyro-Fagetum, species richness is increasing in th e tree tier, the understorey, and ground vegetation. On steep slopes, tree species of the genera Acer, Ulmus and Tilia very locally are dominating. Ri parian forests below ca. 900 m a.s.l. contain Platanus orientalis. On shall ow soil above ophiolith, Pinus nigra ssp. pallasiana is forming small stand s. Ar lower elevations, submediterranean coppice forests consisting mainly of Quercus species become dominant. The altitudinal limit between submedite rranean oak-rich forests, and temperate beech forests differs, depending fr om exposition and subsequent insolation. On south-exposed slopes, the bound ary may be at ca. 1300 m a.s.l., whereas on north-exposed slopes, beech for ests dominate at elevations above ca. 700 m.