The Hybantho durae-Anogeissetum dhofaricae ass. nova -: phytosociology, structure and ecology of an endemic South Arabian forest community

The Hybantho durae-Anogelssetum dhofaricae, a drought deciduous, monsoon forest community in the fog oasis spanning Dhofar/Oman and eastern AlMahra/Yemen is described as a new association. It is characterized by the endemic Combretaceae tree Anogeissus dhofarica and can be classified in the Boscio-Commiphoretea abyssinicae. Beside the typical variant with microphyllous species that is restricted to the most humid sites, a variant of Blepbarispermum birturn, with broad-leaved species inhabiting drier sites and an altitudinal form with numerous evergreen Afromontane species can be distinguished, the latter confined to the upper altitudinal range of the association. The species diversity, structure and stratification, site conditions and effects of human influence on the association are elucidated. A phytogeographical-chorological analysis of the association corroborates its significance as a species-rich, unique, palaeo-African relict of a former continuous belt of xerotropical forests and woodlands, ranging in, the late Tertiary from mainland Asia across the southern Arabian Peninsula to Africa.