An analysis of the coastal vegetation of higher plants in the intertidal and spray zone shows four vegetation types. Species composition of each type is dependent on the topography, salinity and substrate of the coast and the level and frequency of inundation by the sea. Each vegetation type included some indicator species which had only limited use in the classification of the coastal vegetation into biogeographic zones; however, there was a boundary in the distribution of tropical and extra-tropical species. This indicated that climate and geomorphological factors had the major influence on the composition of species. The four vegetation types are as follows: (1) The Limonium-Zygophyllum community is characteristic of the coastal vegetation of northern Oman. The coasts are mainly sandy and interspersed with rocky limestone headlands. The dominant vegetation consists of Limonium stocksii and Zygophyllum qatarense. (2) The Suaeda-Limonium community characterizes the vegetation of the north-eastern coast. This type of vegetation is present in rocky shores with narrow beach areas and a wide spray zone. Limonium cf. swcksii and Suaeda vermiculata form the dominant species. (3) The Atriplex-Suaeda community is characteristic of the vegetation of the offshore islands, flat sandy beaches and sabkhas. The sand is usually fine, graded with mud and has a high content of marine carbonates. This complex consists of the dominant and associated species comprising, Atriplex coriacea, A. farinosum, A. leucoclada, Suaeda vermiculata, S. monoica, S. moschata and Arthrocnemum macrostachyum. (4) The Limonium-Sporobolus-Urochondra community is characteristic of the vegetation of the southern coasts. The dominant species, Limonium axillare, Urochondra setulosa and Sporobolus spp. are associated with several others depending on the geomorphology of the area. Coastal lagoons consists of Sporobolus virginicus, S. iocladus and Paspalum vaginatum as the main species. A single species of mangrove, Avicennia marina, occurs throughout coastal Oman in discontinuous patches and in a wide range of water salinities.

An analysis of the coastal vegetation of higher plants in the intertidal and spray zone shows four vegetation types. Species composition of each type is dependent on the topography, salinity and substrate of the coast and the level and frequency of inundation by the sea. Each vegetation type inclu...