Mountain oases in northern Oman: An environment for evolution and in situ conservation of plant genetic resources

• Published in: Genetic resources and crop evolution 2007-05, Vol.54 (3), p.465-481
• Main Authors: Gebauer, Jens, Luedeling, Eike, Hammer, Karl, Nagieb, Maher, Buerkert, Andreas
• Format: Article
• Language: English
• Subjects: Agave americana; Agrobiodiversity; agroforestry; Arabian Peninsula; Arabic ethnobotany; Aridity; Biodiversity; Biological evolution; Broad beans; Climatic conditions; Crop diversity; Crops; Cultivated flora; Cultivation; Evolutionary conservation; Fruits; Genetic erosion; Genetic resources; Herbivores; home gardens; indigenous knowledge; Lens culinaris; Multicropping systems; Oases; Plant resources; Resource conservation; Species diversity; Species richness; Understory; Vegetation; Vicia faba
• ISSN: 0925-9864; 1573-5109
• DOI: 10.1007/s10722-006-9205-2

Several botanical studies have been conducted in different parts of Oman, but knowledge about agro-biodiversity in the rapidly decaying ancient mountain oases of this country remains scarce. To fill this gap we assessed the genetic resources of three mountain oases in the al-Hajar range using a GIS-based field survey and farmer interviews. While arid conditions prevail throughout the mountain range, the different elevations of Balad Seet (950-1020 m a.s.l.), Maqta (930-1180 m a.s.l.) and Al Jabal al Akhdar (1750-1930 m a.s.l.) provide markedly differing agro-climatic conditions. Overall, 107 different crop species were identified belonging to 39 families. Species number was highest among fruits (33 spp.), followed by vegetables (24 spp.). Intensive irrigation allows cultivation of a broad range of species at all oases. However, the number of species varied significantly between sites. Fruit species diversity and homogeneity of distribution of individual fruit species was highest at Balad Seet and lowest at Maqta as indicated by respective Shannon indices of 1.00 and 0.39 and evenness values of 32% and 16%. Century plant (Agave americana L.), faba bean (Vicia faba L. var. minor Peterm. em. Harz) and lentil (Lens culinaris Medik.) were identified as relict crops, supporting oral reports of past cultivation and providing evidence of genetic erosion. Some species, such as the temperate fruits of Al Jabal al Akhdar, were exclusively found at the coolest site, while others only occurred at the hotter locations. Overall greatest species similarity was found between Balad Seet and Al Jabal al Akhdar as indicated by a Sørensen coefficient of similarity of 67%. At all oases a multilayered vegetation structure dominated with a canopy, an understory and a ground layer. Greatest species richness was recorded in the lowest stratum. Overall the study shows a location-specific but surprisingly diverse mosaic of crops in Omani mountain oases which merits further studies and conservation efforts.