Ecology of tertiary relict endemic Liquidambar orientalis Mill. forests

The oriental sweetgum, Liquidambar orientalis Mill. is a tertiary period relict endemic taxon of the east Mediterranean. The flat deep hydromorphic soils rich in surface waters during summer months are the most productive sites for the dense stands of L. orientalis. It is mainly distributed on sandy soils, with an alkaline pH. The CaCO(3) content in the soils show a medium value and the percentage of total salt content is very low, but organic matter content is higher. The monoecious trees are on an average 15-20 m tall and form dense forests confined to floodplains, valleys and along streams and in a few dry habitats. The plant shows a typical leaf dimorphism with sparsely lobed leaves at the top and many lobed leaves on the lower parts. Fresh seeds germinate well and the percentage varies from 60 to 80. A syntaxonomical synthesis of these forests was carried out. All associations of L orientalis including the newly defined Querco ilicis-Liquidambaretum orientalis association have been evaluated within the alliance Platanion orientalis Karpati & Karpati 1961. This alliance is included in the order Platanetalia orientalis Knapp 1959, and class Alno-populetea Knapp 1959. (C) 2008 Published by Elsevier B.V.