In the south of the country is the Rub' al Khali , or "Empty Quarter", the largest contiguous sand desert in the world. Another sandy desert, the Nefud , lies in the north central part of Saudi Arabia, and it is connected to the Rub' al Khali by a broad swathe of sand dunes and gravel plains known as Dahna. The Red Sea was formed when in the Eocene period, the Arabian Peninsula began to move away from the continent of Africa.
This prevented further exchange of genes between African and Arabian species. Furthermore, the late Tertiary and the early Quaternary eras saw a period of climatic cooling that drove vegetation bands southwards, and the Arabian Peninsula received an influx of species from Eurasia. With increasing aridity, conditions became inimical for many of these and they retreated to the damper, southwestern mountainous regions, becoming relict populations. Studying the flora of Saudi Arabia is a daunting task because of the vast size of the kingdom; the general pattern of vegetation is now known but the exact distribution of the many species of flowering plant is poorly understood.
There are few species of tree but date palms are abundant in places. The east of Saudi Arabia often receives "Mediterranean depressions" from November onwards. The arrival of sufficient quantities of rain causes perennial plants to produce new shoots and the seeds of annual plants to germinate.
These annuals grow with great rapidity and complete their life cycle within a few weeks. By April or May, the annuals will have flowered, set seeds and died, and the perennials returned to a state of dormancy. In desert areas, plant growth is mostly confined to depressions or wadis, though some plants with deep rooting-systems grow elsewhere.
There are virtually no trees, and the plants are adapted for desert life and include dwarf shrubs such as Calligonum crinitum and saltbush , and several species of sedge. The Asir Mountains in the southwest of the country, and most of the western highlands of Yemen, support a distinct flora which has affinities with parts of East Africa. The highest parts are clothed with cloud forests , southwestern Arabian montane woodlands which includes, on north-facing slopes, Juniperus procera and Euryops arabicus , draped with the lichen Usnea articulata , and on south-facing slopes, dwarf shrubs such as Rubus petitianus , Rosa abyssinica , Alchemilla crytantha , Senecio and Helichrysum abyssinicum , with Aloe sabae and Euphorbia in the driest locations.
The fauna of Saudi Arabia has been better studied than the flora, not least because of interest in the larger mammals for the purpose of hunting and shooting. Birds and butterflies have also been studied, but less is known about other parts of the animal kingdom. The Arabian oryx used to roam over Saudi Arabia's deserts and much of the Middle East but by , it had been hunted to extinction in the wild.
The sand cat, which is the only member of the cat family to live exclusively in deserts, can be found in the western region of Saudi Arabia. Chaudhary SA. Flora of the Kingdom of Saudi Arabia. En Icones, Anatomy and morphology, Keys.
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Flora of the Kingdom of Saudi Arabia: illustrated volume 2 part 3. Riyadh : Ministry of Agriculture iii ; En Icones, Anatomy and morphology, Keys, 2. Furthermore, Collenette [ 9 Collenette S. Wild flowers of Saudi Arabia. Osman et al.
Saudi J Biol Sci. Flora of Saudi Arabia includes about plant species. Approximately species subsist in small populations while, species are coexisting in limited areas. Moreover, around species have been recorded as endangered [ 11 Al-Farhan AH. An evaluation of the current status of the flora of Saudi Arabia. In Country report presented at the 2nd Arabian plants subject group meeting, Abu Dhabi; Saudi J Biol Sci ; — The vegetation in the Wadis is variable from year to year. Thomas J. Onward continuously updated.
Int Res J Plant Sci. Howladar SM. J Chem Pharm Res. Food shortage and Lack of available resources are among the most important problems facing Saudi Arabia. Aust J Basic Appl Sci. Vegetation-environment relations in Taif, Saudi Arabia. Int J Botany. Wherefore, Saudi Arabia in had established the Saudi Wild life Commission to preserve wild life and restore ecological balance.
Diversity of perennial plants at ibex reserve in Saudi Arabia. J Anim Plant Sci. This work aims to assess the floristic diversity in fenced areas of Wadi Ar'arregion.
Flora Of Eastern Saudi Arabia (Monographs from the African Studies Center, Leiden)
Furthermore, the life forms, vegetation types and chorotypes of the gathering species taken into seeing. Location map of Saudi Arabia showing main region and study area. Figure 1. Figure 2. Figure 3. Survey of four fenced Areas of Wadi Ar'ar-Northern Border region was conducted between March and March to represent the flora during different seasons.
About positions distributed across all of the major zones of the study area were selected. Plant species registered after complete identification according to Collenette [ 9 Collenette S. A key to the grasses of Arabian Peninsula. Riyadh : Ministry of Agriculture and Water Press ; — Cairo Unvi. Flora of Egypt. I Azollaceae-Oxalidaceae.
Coastal lowland vegetation of eastern Saudi Arabia | SpringerLink
Cairo : A1-Hadara Publishing ; Boulos L. II Geraniaceae-Boraginaceae. Cairo : A1-Hadara Publishing : III Verbenaceae-Asteraceae. IV Monocotyledons Alismataceae-Orchidaceae. Flora of Egypt checklist revised annotated ed. Cairo : Al-Hadara Publishing ; Categories of Life forms were identified after Raunkiaer [ 29 Raunkiaer C.
The plant life forms and statistical plant geography. Oxford : Clarendon Press ; World checklist and bibliography of Euphorbiaceae with Pandaceae. Kew : Royal Botanic Gardens ; Phytogeographical affinities made to determine the listed species in world geographical groups according to Eig [ 31 Eig A. Les elements et les groups phytogeogra-phique auxiliaries dans la florepalestiniene. Feddes Repert. A whole of taxa related to 35 families and genera were recorded in Wadi Ar'ar fenced Areas Table 1.
Chenopodiaceae, Caryophyllaceae, Boraginaceae and Apiaceae were represented by 6. Both Euphorbiaceae and Plantaginaceae were represented by 2. Amaranthaceae, Papaveraceae, Polygonaceae and Zygophyllaceae were represented by 1. Geraniaceae was represented by 1.
Figure 4. In respect to vegetation type, the majority of the registered species in this survey were Annuals with of the total recorded species Figure 5. For more details, see Table 2. According to the classification of Raunkiaer [ 29 Raunkiaer C. Figure 6. Phytogeographically, the listed species were classified into three groups; bioregional, monoregional, or pluriregional [ 31 Eig A. A bout of 93 species Figure 7. In Aoasa, Mayla, Goraba and Aqra, a total of 29 species For more details, see Table 3 , Figures 8 — Floristic category of Aoasa region.
Irano-Turanian-Saharo-Sindian represented by 31 species Mediterranean-Saharo-Arabian regions represented by 4.
Irano-Turanian-Saharo-Arabian regions represented by 1. Irano-Turanian-Euro-Siberian regions represented by 1. In Aoasa, Mayla, Goraba and Aqra, biregional geoelements were represented by 40, 53, , 72 species, respectively. Pluriregional geoelements were represented by Mediterranean-Irano-Turanian-Saharo-Sindian were represented by 6. The remaining 8.
In Aoasa, Mayla, Goraba and Aqra, pluriregional geoelements were represented by 16 The remaining species in Aoasa, Mayla, Goraba and Aqra were 10 The relation between phytogeographical affinities and life forms showed that, Therophytes belonging to Saharo- Sindian represented by Distribution of Therophytes among the different Floristic categories.
Figure Hemicryptophytes belonging to; Irano- Turanian represented by Distribution of Hemicryptophytes among the different Floristic categories. Distribution of Chamaephytes among the different Floristic categories. A total of taxa belonging to 35 families and genera were recorded.