For a long time, the Arabian Peninsula and Africa had a common tropical flora and vegetation, since the Arabian Peninsula was separated from the African continent not earlier than in the Oligocene, 10-15 Mio years BP, and migration and exchange of the palaeo-African, Indo-Malayan and Mesogean floras had taken their course across Arabia.
During the aridisation of the whole region in the late Tertiary, the tropical vegetation was forced into climatically favoured refugia in the mountainous southern part of the Peninsula, with elevations up to 3760 m in the western mountain chain, up to 2100 m in the southern mountain chain, and up to c. 3000 m in the eastern chain of north Oman. This also resulted in the shrinkage and fragmentation of oncecontinuous distributional ranges of species.
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| Map indicating the position of fog oases in the Yemeni southern coastal mountains and on Socotra investigated by the BIOTA Yemen project. |
The southern mountains of the Arabian Peninsula stretch along the southern coast as far as eastern Dhofar in Oman, where they end in the dramatic escarpment of Jabal Samhan. Over vast areas they form an inhospitable limestone plateau at altitudes between 1000 and 1500 m. In Hadhramout they culminate on the seaward side at elevations between 2000 and 2100 m, farther inland they decline gradually, dissected by a labyrinth of gorge-like wadis, towards the desert of the Rub al Khali. In coast-near promontories, however, climatically favoured sea facing escarpments form fog oases, in which relics of woodlands and even forests, consisting apart from the dominating palaeo-African also of Indo-Malayan and Mesogean genoelements, have survived to the present. They show strong affinities to the Somalia-Masai phytochorion of Africa, harbour mesic tropical elements and several endemic species.
These, often island-like refugia have been in the focus of the BIOTA Yemen Project. Investigation of these hitherto largely unexplored fog oases was undertaken in a collaborative effort by several German and Yemeni institutions and researches and funded by the German Federal Ministry of Education and Research during 2001-2004.
Botanic publications with Berlin (BGBM & Institute of Biology) participation of the BIOTA Yemen Project Group "Biodiversity and ecology of palaeo-African refugia in S Arabia"
Oberprieler C., Meister J. Schneider C. & Kilian N. 2009: Genetic structure of Anogeissus dhofarica (Combretaceae) populations endemic to the monsoonal fog oases of the southern Arabian Peninsula. – Biol. J. Linn. Soc. 97: 40-51. doi:10.1111/j.1095-8312.2008.01173.x
Kürschner H., Kilian N. & Hein P. 2008: The Tarchonantho camphoratae-Oleetum cuspidatae ass. nov. – an Afromontane evergreen sclerophyllous community of the Arabian Peninsula with strong relationships to E Africa. – Phytocoenologia 38: 85-106. doi:10.1127/0340-269X/2008/0038-0085
Meister J., Kilian N. & Oberprieler C. 2008 ["2007"]: Genetic structure of Euclea schimperi (Ebenaceae) populations in monsoonal fog oases of the southern Arabian Peninsula. – Nordic J. Bot. 25: 217-226. doi:10.1111/j.0107-055X.2007.00110.x
Kilian N. & Hubaishan M. A. (ed.) 2006: Biodiversity of Socotra. Forests, woodlands and bryophytes. – Englera 28, 175 pp.
Kilian N. & Hein P. 2006: New and noteworthy records for the vascular plant flora of Socotra Island, Yemen. – Pp. 57-77 in: Kilian, N. & Hubaishan, M. A. (ed.), Biodiversity of Socotra: forests, woodlands and bryophytes. – Englera 28.
Kürschner H., Kilian N., Hein P. & Mukram A. 2006: The Adenio obesi-Sterculietum africanae, a relic Arabian mainland community vicarious to the Socotran Adenium-Sterculia woodland. – Pp. 79-96 in: Kilian, N. & Hubaishan, M. A. (ed.), Biodiversity of Socotra: forests, woodlands and bryophytes. – Englera 28.
Kürschner H., Hein P., Kilian N. & Hubaishan M. A. 2006: Diversity and zonation of the forests and woodlands of the mountains of northern Socotra, Yemen. – Pp. 11-55 in: Kilian, N. & Hubaishan, M. A. (ed.), Biodiversity of Socotra: forests, woodlands and bryophytes. – Englera 28.
Kürschner H.: A bryophyte flora of Socotra Island, Yemen. – Pp. 97-162 in: Kilian N. & Hubaishan M. A. (ed.), Biodiversity of Socotra: forests, woodlands and bryophytes. – Englera 28.
Kürschner H.: Syntaxonomy, synecology and life strategies of a saxicolous bryophyte community of Socotra Island, Yemen. – Pp. 163-174 in: Kilian N. & Hubaishan M. A. (ed.), Biodiversity of Socotra: forests, woodlands and bryophytes. – Englera 28.
Meister J. , Hubaishan M. A., Kilian N. & Oberprieler C. 2006: Temporal and spatial diversification of the shrub Justicia areysiana Deflers (Acanthaceae) endemic to the monsoon affected coastal mountains of the southern Arabian Peninsula. – Pl. Syst. Evol. 262: 153-171. doi:10.1007/s00606-006-0459-0
Kilian N., Kürschner H. & Hein P. 2006: Euphorbia greuteri (Euphorbiaceae), a new single-spined succulent from the foothills of Jabal Urays, Abyan, Yemen. – Willdenowia 36 (1-Special Issue): 441-446. doi:10.3372/wi.36.36141
Meister J., Hubaishan M. A., Kilian N. & Oberprieler C. 2005: Chloroplast DNA variation in the shrub Justicia areysiana (Acanthaceae) endemic to the monsoon affected mountains of the southern Arabian Peninsula. – Bot. J. Linn. Soc. 148: 437-444. doi:10.1111/j.1095-8339.2005.00421.x
Kilian N., Hein P. & Hubaishan M. A. (ed.) 2004: Further notes on the flora of the southern coastal mountains of Yemen. – Willdenowia 34: 159-182. doi:10.3372/wi.34.34114
Kürschner H., Hein P., Kilian N. & Hubaishan M. A. 2004: The Hybantho durae- Anogeissetum dhofaricae ass. nova – phytosociology, structure and ecology of an endemic South Arabian forest community. – Phytocoenologica 34: 569-612. doi:10.1127/0340-269X/2004/0034-0569
Kürschner H. & Ochyra R. 2004: Remarkable new records to the bryophyte flora of Yemen (al-Mahra and Socotra Island). Additions to the bryophyte flora of the Arabian Peninsula and Socotra 6. – Cryptogamie, Bryol. 25: 69-81.
Kürschner H. & Sollman P. 2004: New and noteworthy bryophyte records for the flora of Yemen. Additions to the bryophyte flora of the Arabian Peninsula and Socotra 8. – Willdenowia 34: 301-308. doi:10.3372/wi.34.34126
Kürschner H. 2004a: Intracapsular spore germination in Brachymenium leptophyllum (Müll. Hal.) A. Jaeger (Bryaceae, Bryopsida) – an achorous dispersal phenomen. – Nova Hedwigia 78: 447-451.
Kürschner H. 2004b: Phytosociology, ecology and life strategies of a remarkable epiphytic bryophyte community of Socotra Island, Yemen. – Bot. Jahrb. Syst. 125: 377-395.
Kürschner H. & Ochyra R. 2003: Erpodium glaziovii (Erpodiaceae, Bryopsida) and further novelties from the Arabian Peninsula. Additions to the bryophyte flora of the Arabian Peninsula and Socotra 4. – Willdenowia 33: 205-210.
Kürschner H. 2003a: Further new bryophytes from Socotra and the Yemen mainland, including Papillaria crocea (Hampe) A. Jaeger (Meteoriaceae, Bryopsida), a palaeotropical Asian species. – Additions to the bryophyte flora of the Arabian Peninsula and Socotra 3. – Nova Hedwigia 76: 257-267.
Kürschner H. 2003b: The Riccietum jovet-astii – argenteolimbatae ass. nov. of the Jabal Arays area, Yemen – life strategies of a remarkable xerotropical African bryophyte community. – Nova Hedwigia 76: 399-413.
Kürschner H. 2003c: Epiphytic bryophyte communities of southwestern Arabia – phytosociology, ecology and life strategies. – Nova Hedwigia 77: 55-71.
Kürschner H. 2003d: Nineteen new records to the bryophyte flora of Socotra island. – Willdenowia 33: 445-458.
Sipman H. J. M. 2002: Lichens of mainland Yemen. – Willdenowia 32: 127-135.
Kilian N., Hein P. & Bahah S. O. 2002: A new species of Campylanthus (Scrophulariaceae) from Ras Fartak, Al-Mahra, and notes on other species of the genus in Yemen. – Willdenowia 32: 271-279.
Kilian N., Hein P. & Hubaishan M. A. 2002: New and noteworthy records for the flora of Yemen, chiefly of Hadhramout and Al-Mahra. – Willdenowia 32: 239-269.
Kilian N. & Hubaishan M. A. 2002: Tephrosia dura, Leguminosae. – Curtis's Bot. Mag. 19: 241-246.