Oman

MAIN PHYTOGENETIC RESOURCES OF OMAN AND THE MAIN THREATS

Oman has over 1,100 flowering plant species. While the Dhofar region is very similar in physical geography to the island of Socotra, north-east Africa and southern Iran, the rest of the country is desert. In Dhofar there are two genera and around 50 species of endemic plants, showing that the region provides shelter for relict flora. These are mostly to be found in the monsoon woodlands of Dhofar and, to a lesser extent, in the mountains in northern Oman.

Five ecological regions have been identified (Lawton, 1988) in Oman, their dominant vegetation being as follows:

• Desert:Dichanthiumfovcolatum, Zygophyllum sp., Herniaria sp., Farsetia
  longisiliqua.
• Desert:Limoniumaxillare, Aristida adscensionis, Heliotropium sp, Aristidaadscensionis, Zygophyllum sp., Fagonia sp. Jauberia aucheri.
• Semi-desert:Violacinerea, Kickexia hastata, Farsetia longisiliqua, Helichrysumsomalense.
• Semi-desert(scrubland):Eragrostisciliansis, Kickexia hastata, Aristida adscensionis.
• Pastureland:Themedaquadrivalis, Brachiaria deflexa, Setaria pumila, and the genera Cenchrus,Chloris, Dactyloctenium and Dichanthiu. On the dry coastal plainsthere are areas of pastureland dominated by Eremopogonsp., Cenchrus pennisetiformis,Leptothrium senegalense and Cenchrus setigerus.

The most frequent tree species in Oman are distributed as follows:

1. Semi-desertwith pasturelands and occasional Acaciatortilis on alluvial soil, and Commiphora and succulent shrubs on some rockyoutcrops on the coastal plain. Shrublands include Acaciaetbaica, Dracaena serrulata, Commiphora sp., and Grewia spp.
2. Deciduousscrub withBosciaarabica, Commiphora sp., Jatropha dhofarica, confertus Croton,Adenium obesum Grewia spp, and Cissus quadrangularis.
3. Onsteep slops up to 500 metres in altitude there are areas ofdeciduous shrubs and scrub, mostlyspecies of Commiphorasp., Acacia senegal, Maytenus dhofarensis,Croton confertus, Andgeissus dhofarica, Delonix elata and Sterculia africana. Above500 m, there is scrub with Commiphora sp.,Oka africana, Dodonaea angustifolia, Euclea shimperi andFicussp.,mostly riparian woodland.
4. Onhigh plateaux there are pasturelands with Euphorbiabalsamifera.
5. Desert:AtNejd, there is Boswelliasacra and Accacia etbaica. A typical thorny tree isPropsopiscineraria,which may be found in isolation in the very rich ecological habitatof theAl-Wahibasand desert.

Some genera represented by their wild relations in Dhofar are:
Amaranthus, Pistacia, Lactuca, Ipomoea, Citrullus, Cucumis, Ricinus, Vigna, Abelomoschus, Gossypium, Ficus, okra, Citrus, Corchorus (Dicotiledons), Eleusine and Panicum, Pennisetum, Saccharum, Setaria, etc. Amongst the wild relations of more important crop species are Abelmosehus esculentus and A. manihot, Cucumis sativus and C. melo, Gossypium stocksii and Vigna radiata var. Sublobata. Other relatively less frequent crop genera include Ziziphus, Lavandula, Ocimum, Solvia, Acacia, Alysicarpus, Desmodium, Indigofera, Lotus and Rhynochoria.

According to data taken from “Oman: Country Report to the FAO International Technical Conference on plant genetic resources“ (Leipzig, 1996), in Oman there are serious conservation problems, partly due to progressive degradation of soil and water quality mostly caused by the desalination that results form excessive urbanisation and by excessive use of pesticides and herbicides. In mid-1993, a programme was set up to study the toxicity and persistence of pesticides for the country’s fauna and flora.

Inaddition, because of importsand selection of high-yield genotypes, the survival of local geneticresources is at risk. International collaboration with the IBPGR,ICARDA, Kew Gardens and the IITA is essential in this area.

STATUSOF IN-SITU AND EX-SITU CONSERVATION

In-situ conservation

Reearch is being carried out on the techniques and viability of reforestation in three “Pilot forest areas” and at a “Forestry Research Site” at the Rumis Agricultural Research Centre. The pilot areas cover 40,000 ha and are protected by fences. In them, preference is given to the use of native tree species, such as Ghaf (Prosopis cineraria), Sidr (Ziziphus spina-christi) and Samar (Acacia tortilis). There is also data on planted areas in Mejais (near Sohar), where about 1,600 trees have been planted. This is an exceptional location for evaluating the development and growth of native and exotic species under saline conditions. In Kubarah (near Ibri) over 700 trees have been planted. There is also a site at Danq (near Ibri).

According to data taken from “Oman: Country Report to the FAO International Technical Conference on plant genetic resources” (Leipzig, 1996), there are a number of shortcomings in the country for in-situ germplasm conservation, namely:

• Stafftrained in collection, conservation,identification and cataloguing of plant species.
• Qualityequipment and facilities for research in this area.
• Fluid sharing ofinformation with other institutes on similar actions.
• Availability of data ongermplasm collected previously in Oman.
• Availabilityof appropriate software to characterise and evaluate crops.

Ex-situ conservation

As a result of prospection carried out by the IBPGR in 1980, eleven alfalfa germplasm collections were set up. During 1987 and 1988, the Ministry of Agriculture and Fishing invited Dr. L. Guarino (collector from Cyprus for the IBPGR) to collect local germplasm for all crops in Oman. All of this has been conserved.

The General Department for Agricultural Research has research and experimentation farms and 12 nurseries in which tropical and sub-tropical fruit trees are grown systematically for the purpose of research. Today there is a germplasm bank at Wadi Quriyat in Oman. A number of locations have been proposed for gene banks/orchards in Oman:

• Sohar:cultivation and experimentation with mango
• Salalah:banana, coconut,papaya, guava
• Jimmah:grape
• Tanuf:pomegranate
• Rumais:lime

Centers of plant diversity

Oman is in south-west Asia, on the south-east coast of the Arabian Peninsula. It borders with United Arab Emirates to the north-west, Saudi Arabia to the west and Yemen to the south west. It has coasts on the Arabian Sea to the south and east, and the Gulf of Oman to the north-east. It also has two enclaves: the Musandam peninsula to the north of United Arab Emirates, and Madha to the east of the Emirates.

Oman has almost 1,600 km of coastline and four natural regions: the coastal plain; a vast, flat desert covering most of the centre of the country; Dhofar to the south, where the city of Salalah is located; and the mountain range along the north coast. The highest mountain is Jabel Sham, with an altitude of 3,000 metres. Between the mountains and the north coast is a narrow strip where most of the country’s main cities are located – Muscat (the capital), Sohar and Sur. The climate of Oman is hot and dry inland but humid along the coasts.

The Musandam peninsula, strategically located on the Strait of Ormuz, is separated from the rest of the country by United Arab Emirates. Not all of Oman’s frontiers with this country have been defined. Oman also has an exclave within the UEA, the city of Madha.

Inland, to the west, is the Rub al Khali desert, one of the earth’s most inhospitable regions. Together with the Wahiba sands, further to the east, this desert forms part of the ecoregion called desert and xeric shrublands of Arabia and Sinai.The climate gradually becomes more humid towards the south coast, as the ecoregions change from Red Sea tropical desert and semi-desert, to south-western Arabian foothills savannah and Arabian peninsula cloudy coastal desert. Towards the west, the biomes can be distinguished by their altitude: the coast and low areas form part of the desert and semi-desert of the Gulf of Oman, whereas in the mountainous areas the biome is Al Hajar montane woodlands.