The document discusses plant communities and formations in Saudi Arabia, defining a plant community as a collection of species influenced by environmental factors. It outlines five vegetation categories in the region, including coastal areas, deserts, dwarf shrublands, woodlands, and wadi communities, along with dominant species in each category. The text emphasizes the diversity of plant associations across varying environments, detailing specific species found in different geographic areas.

1. Plant Community:
A plant community (phytocenosis) is a collection or
association
of plant species within a designated
geographical unit, which forms a relatively uniform
patch, distinguishable from neighboring patches of
different vegetation types.
The components of each plant community are
influenced by soil type, topography, climate and human
disturbance.

2. Plant Formation:
a group of plant associations whose main
strata consist of the same species. A plant
formation can include genetically and
ecologically different associations.

3. Vegetation of Saudi Arabia is generally divided into
five broad categories.
1.Coastal plains and Sabkhas
2.Deserts and scarcely vegetated areas
3.Dwarf shrublands
4.Woodlands and xeromorphic shrublands of high
altitude areas.
5.Wadi Communities.

4. Coastal and sabkha vegetation and open drought deciduous thorn woodlands (1 and
13), Deserts and sparsely vegetated areas (8, 9 & 11), Dwarf shrublands and related
communities (10 & 12), Montane woodlands and xeromorphic shrublands (2, 3, 4, 5, 6
& 7), Wadi Communities (14)

5. • In the western (Red Sea) and eastern sides
(Arabian Gulf).
• Mangroves, halophytes, open xeromorphic
and drought-deciduous thorn woodlands
dominate the coastal zones of Arabian Gulf
and Red Sea.

6. • Halocnemum strobilaceum, Halopeplis perfoliata,
Limonium axillare, Nitraria retusa, Odyssea mucronata,
Suaeda monoica, S. vermiculata, Zygophyllum coccinium,
Z. simplex.
• Mangrove stands, represented by Avicennia
marina and Rhizophora mucronata

7. Halocnemum strobilaceum Limonium axillare
Suaeda monoica Zygophyllum coccinium
Avicennia marina
Rhizophora mucronata

9. A. Open xeromorphic dwarf-shrublands of rock and gravel
deserts.
Dominant species: Acacia tortilis, Haloxylon salicornicum,
Astragalus spinosus, Achillea fragrantissima, Salvadora persica,
Cadaba farinosa , Leptadenia pyrotechnica, Halothamnus bottae

10. Halothamnus bottae Cadaba farinosa Leptadenia pyrotechnica

11. B. Deep sands
Calligonum comosum, Haloxylon persicum, Dipterygium glaucum,
Tribulus macropterus var. arabicus, Artemisia monosperma,
Stipagrostis drarii, Scrophularia hypercifolia, Eremobium
aegyptiacum, Cyperus conglomeratus, Cutandia memphitica,
Plantago boissieri, Centropodia forsskalii

12. Dipterygium glaucum Artemisia monosperma Centropodia forsskalii
Stipagrostis drarii Eremobium aegyptiacum Plantago boissieri

13. C. Scarcely vegetated sand dunes and sand covered gavel
plains.
Dominant species: Acacia spp. and Calligonum comosum.
Calligonum comosum

15. A. Very open Xeromorphic dwarf shrublands
Dominant species: Calligonum comosum, Haloxylon
salicornicum
Calligonum comosum

16. B. Open xeromorphic dwarf shrublands
Dominant species:
Haloxylon salicornicum,
Rhanterium epapposum,
Acacia gerrardii,
Acacia ehrenbergiana,
Ziziphus nummularia,
Lycium shawii.

17. A. Drought deciduous thorn woodlands and shrublands (Acacia-
Commiphora )
(Jeddah-Taif) (Asir) (near Yemen border)
B. Drought deciduous thorn woodlands (Acacia woodlands along the
western and eastern upper slopes)
C. Semi evergreen Sclerophyllous woodlands and sclerophyllous scrub
(Taif Mountains) (Asir Mountains)
D. Evergreen Needle-leaved Woodlands. (Vegetation of highest part of
the northern and southern Hijaz Mountains)
(northern mountains) (Taif Mountains) (Jabal Soodah) (Jizan Province)
E. Mixed formations of drought deciduous shrublands, xeromorphic
succulent shrublands and open xeromorphic grasslands & very open
xeromorphic semi-desert shrublands.(East facing and north facing
slopes)

18. A. Drought deciduous thorn woodlands and
shrublands (Acacia-Commiphora )
Dominant species of northern parts of southern Hijaz
Mountains (Jeddah-Taif): Acacia asak, A.
ehrenbergiana, A. hamulosa, A. etbaica,
Commiphora kataf, C. myrrha, Delonix elata,
Euphorbia cuneata, Maytenus senegalensis

20. A. Drought deciduous thorn woodlands and
shrublands (Acacia-Commiphora )
Dominant species of the middle parts of southern
Hijaz Mountains (Asir): Acacia ehrenbergiana, A.
hamulosa, A. mellifera, Cadaba farinosa, Dobera
glabra, Maerua crassifolia, Euphorbia fractiflexa,
Indigofera spinosa, Panicum turgidum, Chrysopogon
plumulosus, Blepharis ciliaris,

22. A. Drought deciduous thorn woodlands and shrublands
(Acacia-Commiphora )
Dominant species of the southern parts of southern Hijaz
Mountains (adjoining mountains near Yemen border) Acacia
ehrenbergiana, A. mellifera, A. tortilis, Adenium obesum, Aloe
officinalis, Combretum molle, Delonix elata, Dobera glabra,
Hyphaene thebaica, Maerua crassifolia
Adenium obesum Aloe officinalis Combretum molle

23. B. Drought deciduous thorn woodlands
(Acacia woodlands along the western and eastern
upper slopes)
Dominant species: Acacia asak, A. etbaica, A.
origena, Adenium obesum, Anisotes trisulcus, Barleria
bispinosa, Cadia purpurea, Grewia spp.
Anisotes trisulcus Barleria bispinosa Cadia purpurea

24. C. Semi evergreen Sclerophyllous woodlands and
sclerophyllous scrub
Dominant species: (Barbeya oleoides-Olea europaea
community of the Taif Mountains) Acacia etbaica,
Dodonaea viscosa, Olea europaea

25. C. Semi evergreen Sclerophyllous woodlands and
sclerophyllous scrub
Dominant species: (Barbeya oleoides- Olea europaea
community of Asir Mountains) Buddleja polystachya,
Carrisa edulis, Celtis africana, Nuxia congesta,
Maesa lanceolata, Tarchonanthus camphorates
Buddleja polystachya Olea europaea

26. D. Evergreen Needle-leaved Woodlands.
(Vegetation of highest part of the northern and
southern Hijaz Mountains)
Dominant species of northern mountains: Juniperus
phoenicea, Artemisia seiberi, Tanacetum
santolinioides, Launaea spinosa, Eringium
glomeratum, Prunus korshinskyi, Asperagus aphyllus,
Astragalus sparsus

28. D. Evergreen Needle-leaved Woodlands.
(Vegetation of highest part of the northern and
southern Hijaz Mountains)
Dominant species of Taif Mountains: Juniperus
procera, Euryops arabicus, Psiadia punctulata, Rhus
retinorrhea

30. D. Evergreen Needle-leaved Woodlands.
(Vegetation of highest part of the northern and
southern Hijaz Mountains)
Dominant species of Jabal Soodah: Acacia seyal,
Erica arborea, Juniperus procera, Lavandula dentata,
Rumex nervosus, Rosa abyssinica, Dodonaea
angustifolia, Carissa edulis .

32. D. Evergreen Needle-leaved Woodlands. (Vegetation of highest part of
the northern and southern Hijaz Mountains)
Dominant species of the mountains of Jizan Province: Juniperus procera,
Acacia gerrardii, Euryops arabicus, Dodonaea angustifolia, Hypericum
revolutum, Cordia abyssinica, Nuxia congesta, Rosa abyssinica

33. E. Mixed formations of drought deciduous
shrublands, xeromorphic succulent shrublands and
open xeromorphic grasslands & very open
xeromorphic semi-desert shrublands.(East facing
and north facing slopes)
Dominant species: Vegetation of these areas are
mainly dominated by succulent plants such
as Euphorbia spp., Dracaena, Klenia and Aloe along
with Acacia gerrardii, A. oerfota and A. etbaica.

34. • Several plant communities have been
identified along the banks and wadi bottom,
especially along the wadis of Najd and
Tihama areas.
• Main wadis in Saudi Arabia are Wadi Rimah,
Wadi Fatima, Wadi Hanifa, Wadi Dawasir,
Wadi As Sabha, Wadi Nissah and Wadi Al-
Batin

36. A. Dominant species of the Central region: Acacia
gerrardii, A. raddiana, A. ehrenbergiana, A. tortilis,
Rhazya stricta, Lycium shawii, Pennisetum
divisum, Lasiurus scindicus, Ochradenus baccatus,
etc.

37. B. Dominant species of Tihama region: Acacia
ehrenbergiana, Ziziphus spina-christi, Salvadora
persica, Leptadenia pyrotechnica, Tamarix nilotica,
Hyphaene thebaica, Abutilon pannosum, Panicum
turgidum, Desmostachya bipinnata, Dobera glabra,
etc.