An Assessment of Biodiversity in Tabuk Region of Saudi Arabia: A Comprehensive Review

Abstract

Biodiversity refers to all the type of species in one geographical region or ecosystem. It consists of plants, animals, bacteria, and other life forms. As an estimate, around 1.7 million species are on record globally and approximately 15,000–18,000 new species are added each year. Global climate change is accelerating species extinction due to habitat destruction. Further, various abiotic and biotic environmental factors are limiting the pattern of biodiversity in a geographical region. A change in species category from endangered to extinction occurs due to their physiological, morphological, and life history pattern, which limits them to a specific niche. Biodiversity is very important for energy production and flow, bioremediation, and biogeochemical cycling of nutrients in terrestrial to aquatic ecosystems and vice versa. It is further required for human existence in the form of food, fibers, medicines, and biological control. Therefore, consistent monitoring, assessment, and conservation of ecological habitats and diversity of flora and fauna of aquatic and terrestrial ecosystems is the need of the hour. In this article, we are presenting an assessment based upon the literature survey on the biodiversity of Tabuk region of Kingdom of Saudi Arabia. A comprehensive study on the biodiversity of plants, animals and microorganisms of the Tabuk region (Tabuk city, Tayma, Haql, Sharma, Duba, Al Wajh and Umluj, Al Zetah, Al Beda’a, etc.) are included in this review. This study will be a landmark as it is conducted at the inception of NEOM project in Tabuk region. It will help the authorities to enhance the native green cover, decrease desertification, regenerate biodiversity in natural environments, and advance the quality of life, to achieve the objectives of the Saudi Green Initiative and VISION 2030. However, studies and investigations on Tabuk biodiversity are still limited and need further exploration. Recently, a joint work between King Salman Royal Natural Reserve (KSRNR) and Department of Biology of University of Tabuk is underway to monitor the baseline data of flora and fauna of this region.

1. Introduction

The Northwest region of Saudi Arabia is administratively part of the Tabuk Province and is the current hotspot for agricultural activities in the region. Traditionally, this region is known as Midyan (Midian or Madyan) and has an area of almost 135,000-km² [1]. It includes diverse terrain such as deserts, valleys, sprawling mountains, coasts of the Red Sea, and natural springs. Long shoreline of Tabuk Province is one of the most important geographical characteristics that contributes about 38% of the western shoreline of Saudi Arabia. It covers coastal cities, such as Haql, Sharma, Duba, Al Wajh and Umluj, with pristine beaches of clear waters (Figure 1).

Figure 1. A map demonstrates locations of Tabuk biodiversity research.

The province of Tabuk contains five major habitats, namely, mountains, coastal and islands, water bodies, plains and valleys with scattered trees, and agricultural and urban environment. The Tabuk region hosts several unique natural attractions occupying considerable natural resources. Tabuk is a desert with relatively little rain, the average temperature is 21.7 °C and precipitation is about 15 mm per year. In 30-year investigations on temperature between 1984 and 2013, trends have shown significant increase in warming of the atmosphere of about 1.93 °C [2]. The unique terrains of the Tabuk region and the distinctive climatic condition from extremely low to extremely high results in diverse terrestrial and aquatic ecosystems, which harbor a remarkable biological diversity [1,3,4,5,6,7,8].

Biodiversity refers to all of the types of species in one geographical region or ecosystem. It consists of plants, animals, bacteria, and other life forms. As per Catalogue of Life-2018 Annual Checklist [9], around 1.7 million species are on record globally and approximately 15,000–18,000 new species are added each year [10]. Broadly, biodiversity can be observed at three levels, namely, ecosystem, species and genetic level (Figure 2). The biodiversity is a crucial and a vital environmental component for a functional ecosystem. It is very important for energy production and flow, bioremediation, and biogeochemical cycling of nutrients in terrestrial to aquatic ecosystems and vice versa [11]. Since the dawn of civilization, it has been very active in offering humanity with food security, medical care, and goods and materials for various industries, and allows humans to live a comfortable life [12]. However, in the modern world, due to increases in various anthropogenic activities, a surge in global climate change is observed. It affected almost all kinds of habitat globally and resulted in a huge decline in plant diversity. The decline in producer community compels a change in the fauna of the affected habitat [13,14,15]. The species extinction across the globe is mainly governed by changing environmental conditions due to habitat destruction. Various abiotic environmental factors, such as nutrients, pH, water availability, soil quality, temperature, and many other climatic changes, and biotic factors, such as primary producers (green plants, consumers (herbivores, carnivores, and omnivores) and decomposers (microorganisms), are limiting to biodiversity patterns. Any species can be shifted to endangered or extinction due to their physiological, morphological, and life history pattern, which limit each species to a specific niche. In order to conserve the biodiversity of Saudi Arabia, legislation was enacted and The Saudi Wildlife Authority (SWA) was established in 1986. Its task was to develop a national network of protected areas and to pursue the restoration of native endangered species. The Wildlife Protected Areas Act was issued in 1995 to facilitate conservation activities and the establishment of protected areas in Saudi Arabia. Since its inception, SWA has identified 16 protected areas covering 86,582.4 km² and a further 22 areas planned, covering a total area of 208,356 km², 10.42% of the KSA [16]. In 1996, the Government of Saudi Arabia joined CITES, which regulates international trade in listed species and CITES implementing legislation (The Act on Trade in Endangered Wildlife Species and their Products 2000) was introduced in 2001 in KSA. The fauna was protected from poaching and illegal trades by enacting The Wild Animals and Birds Hunting Act 1999. As per this law, hunting was banned without a license, regulations were defined, and penalties were listed in case of violations. An Environmental Code 2002 was also formulated for the protection of the environment [17,18]. Later, the Government of Saudi Arabia joins the Convention on Biological Diversity [17]. Since joining the Convention, Saudi Arabia has made remarkable and significant progress in addressing biodiversity conservation and its related challenges [19].

Figure 2. Different levels for the biodiversity assessments.

Recently, the hunting regulation for wildlife terrestrial species (2020) [20] was implemented by The Ministry of Environment, Water and Agriculture, represented by the National Center for Wildlife Development. The ministry prohibited the hunting of Arabian oryx, deer, and ibex; predators, such as the Arabian tiger, lynx, wolf, and hyena; and other endangered species of animals and birds, as well as birds of prey. The ministry further laid down the prohibition of hunting of all kinds of animals or birds within the boundaries of cities, villages, towns, farms and rest houses, or any inhabited places, or near cities and military, industrial, and vital installations. Moreover, hunting is not allowed within the boundaries of natural reserves and giant development projects, such as NEOM, the Red Sea, Amaala, Al Qiddiya, the Al-Soudah Reserve, and the Royal Commission for Al-Ula [21]. The approved regulations for trafficking fungal organisms (2020) [22] prohibits hunting wild fungi organisms, endangered species, and overfishing. The law ensures a safe and protected environment without harming the balance of the natural ecosystem [23].

In view of VISION 2030, Royal Commission for Al-Ula was established in 2017 for conservation and sustainable development of Al-Ula, a leading global destination for cultural and natural heritage in Tabuk province. Royal Commission for Al-Ula granted a government membership status by International Union for Conservation of Nature (IUCN). Together, they will conserve nature and wildlife by creating and activating nature reserves. It will protect degraded ecosystems, ecological processes, fragile habitats, biodiversity, and reintroducing native species [24]. Similarly, the KSA government launched Saudi Green Initiative (2022) [25]; its main goals are to reduce annual CO₂ emissions by 278 million tonnes by 2030, plant 10 million trees nationwide, and protect 30% of land and sea by developing creative solutions to tackle climate change.

Despite establishment and implementation of various laws and regulations for wildlife protection, there are many reports for the illegal trade and violations from different regions of in Saudi Arabia, particularly from Tabuk region. There is an urgent need to strengthen the law enforcement, as well establishing an awareness campaign to conserve threatened species especially birds, reptiles, and carnivorous animals in Saudi Arabia. In this review, an analysis of published literature is done that can provide a comprehensive data on the biodiversity of Tabuk region of Kingdom of Saudi Arabia. A wide-ranging study on the biodiversity of plants, animals, and microorganisms of the Tabuk region are included in this review. The latest published data of the last decade was collected using Science Direct, Springer, MDPI, Google, Google Scholar, etc. The articles, reviews, short communication, and reports were studied thoroughly and grouped based on plants, animals, and microorganisms. This study will be a landmark as it is done at the inception of mega developmental projects like NEOM, LINE, Red Sea Development Company, AMAALA, etc., in Tabuk region and can be taken as a baseline knowledge of biodiversity of Tabuk region. It will help the authorities to understand the basic diversity of organism of Tabuk and helps in the enhancement of the native green cover. This will decrease desertification, regenerate biodiversity in natural environments, and advance the quality of life, to achieve the objectives of the Saudi Green Initiative and VISION 2030. This article also assesses the gaps in biodiversity research and suggest biodiversity surveys and studies.

2. Plant Biodiversity of Tabuk Region

Tabuk and the surrounding area are composed of metamorphic and igneous rocks. The western part of the region is surrounded by a series of hills and mountains, including Jabal al Lauz, Hijaz mountains. The terrain is similar to that of central Najd and consists of wadi, hills, and plains. Wadi are generally filled with muddy sand and gravel and plain soil sediments range from silt to sand to coarse rocks. Some of the most important agricultural centers are also found on the eastern and southeastern sides of Tabuk City [26]. The pioneer work to identify the plant biodiversity of Saudi Arabia was conducted by [27,28] in the form of an Illustrated Guide to the Flowers of Saudi Arabia and Wild Flowers of Saudi Arabia. Moreover, Migahid (1989) [29] and Chaudhary (2001) [30] completed the Flora of Saudi Arabia. Since then, there is a need to update the Flora of Saudi Arabia in general and Flora of Tabuk in particular due to the inception of megaprojects like NEOM, LINE, Red Sea Development Company, AMAALA etc. Nowadays, a field survey project for the baseline data for vegetation and wildlife life of King Salman Royal Natural Reserve is in its final phase. After the completion of this project, a clear picture will appear regarding the biodiversity of Tabuk region [31]. In the following paragraph, an attempt is made to collect the available information about the plant biodiversity of Tabuk region.

2.1. Algal Biodiversity

Algae is a group of different organisms capable of producing oxygen through photosynthesis. However, though these organisms are not closely related, they share some common features with the major group of photosynthetic organisms, plants. The coastline of Tabuk region along the Red Sea is the harbor for marine algae. As per the literature survey and the published reports in Tabuk region, seasonal dynamics and ecological parameters of marine algae are recorded by various workers [5,32,33,34,35,36]. However, Al Solami (2020) [37] studied the comparative response of red and green algae in relation to the quality of coastal waters of Red Sea at Haql region. Recently, Menaa et al. (2021) [38] reviewed the marine algae derived bioactive compounds as a source of Nanodrugs. Alshehri et al. (2021) [39] worked for the molecular characterization of some algae collected from the Gulf of Aqaba using protein banding pattern and ISSR markers. There are various genera of algae reported from Tabuk region listed in Table 1.

Table 1. List of Algae Reported from Tabuk Region of KSA.

S. No.	Name of Algae	Occurrence (Reported from)	References
1	Enteromorpha intestinalis, Padina pavonia, Cystoseira myrica, Cystoseira trinodis, Colpomenia sinuosa, Turbinaria ornate, Sargassum latifolium, Laurencia majuscule, Laurencia catarinensis, Laurencia papillosa, Laurencia sp., Laurencia sp., Liagora hawaiiana Butters, Hypnea bryoides Børgesen, Palmaria palmate, Galaxaura rugose, Gracilaria arcuate, Acanthophora spicifera, Digenia simplex	Umluj	Ibraheem et al., 2014 [40]
2	Gastroclonium ovatum, Ulva lactuca, Padina pavonica, Enteromorpha flexuoca, Hildenbrandia rubra, Polyides rotundus, Cladophora rupestris, Nemalion helminthoides	Haql, Duba	Ansari et al. (2015) [5]
3	Jania rubens, Gastroclonium ovatum, Padina pavonica, Hildenbrandia rubra, Nemalion helminthoides, Polyides rotundus, Cladophora prolifera, Ulva lactuca, Enteromorpha flexuoca, Gracilaria Salicornia, Digenia simplex, Chaetomorpha linum, Pterocladia capillacea	Haql, Duba	Ansari et al. (2016) [32]
4	Ulva lactuca, Enteromorpha flexuoca, Cladophora prolifera Chaetomorpha linum	Haql	Ansari and Ghanem (2017) [33]
5	Padina pavonica	Haql	Ansari and Ghanem (2019) [34]
6	Padina, Sargassum, Dictyota, Polysiphonia, Ulva	Haql	Ansari et al., 2020 [35]
7	Gracilaria salicornia, Digenea simplex, Enteromorpha compressa, Sargassum muticum	Haql	Mazen & Solami (2020) [37]
8	Turbinaria gracilis, Carpomitra costata, Pterocladiella capillacea, Cladostephus spongiosus, Ulva lactuca, Sporochnus comosus, Sargassum muticum	Haql	Alshehri et al., 2021 [39]

Ibraheem et al. (2014) [40] reported some algal species from Umluj coasts of the Red Sea, namely, Enteromorpha intestinalis, Padina pavonia, Cystoseira myrica, Cystoseira trinodis, Colpomenia sinuosa, Turbinaria ornate, Sargassum latifolium, Laurencia majuscule, Laurencia catarinensis, Laurencia papillosa, Laurencia sp., Laurencia sp., Liagora hawaiiana Butters, Hypnea bryoides Børgesen, Palmaria palmate, Galaxaura rugose, Gracilaria arcuate, Acanthophora spicifera, and Digenia simplex. Ansari et al. (2015) [5] studied eutrophication in coastal waters, and floral and faunal density in relation to the seasonal dynamics of some selected coastal areas at Haql, Sharma and Duba of the Red Sea in Tabuk region. Only few coastal sites showed eutrophic characteristics. Water samples from these sites were more turbid, alkaline, and with higher nutrient and low dissolved oxygen contents compared to other sampling sites. A variation in relative densities of coastal flora and fauna were recorded and correlated with coastal water quality. The authors concluded that the fish markets, boating clubs, and touristic and human settlements at the coastal areas may be the prime reason of run-offs and nutrient loading rains aggravate the problem.

Ansari (2016) [32] studied the relative density of aquatic flora in relation to the seasonal dynamics and concluded that the summer season (April, May, June, and July) of Tabuk can be considered as the most suitable period for the collection of aquatic plants for medicinal purpose and ecological studies. Ansari and Ghanem (2017) [33] studied seasonal variation in growth responses and antioxidant activities of Ulva lactuca, Enteromorpha flexuoca, Cladophora prolifera, Chaetomorpha linum).

In July and October, significantly higher accumulation of NPK, carbohydrates, total protein, photosynthetic, and accessory pigments was recorded; however, a significant decrease in January was observed for the same parameters (Ansari and Ghanem 2017). Significant antioxidant activities in all the species were observed in January, which may be due to low temperature stress as compared to the other months. Various Biotic factors (plants, animals, and microorganisms) and abiotic factors (nutrients, soil quality, water, temperature, pH, salinity, and light) are the limiting factors for the production of primary and secondary metabolites. Ansari and Ghanem (2019) [34] also studied the growth attributes and biochemical composition of a brown alga Padina pavonica (L.) from the Red Sea at Haql in different seasons. The carbohydrate, protein and lipids, mineral ashes, macronutrients, and dietary fibers were high in July. The antioxidant enzymatic activities and proline accumulation showed a response to abiotic stress (low temperature) in January. A quantitative analysis on the diversity of algal flora revealed that the frequency, density, and abundance of Sargassum sp. was highest whereas of Ulva sp. was least at the six different study sites of Haql [35]. Five common algal species, namely, Padina, Sargassum, Dictyota, Polysiphonia, and Ulva were reported in their study. Mazen & Solami (2020) [37] compared the responses of Red algae (Gracilaria salicornia and Digenea simplex) and Green Algae (Enteromorpha compressa and Sargassum muticum) to the water quality at the coast of Red Sea. A significant variation in physiological and biochemical parameters of algae was observed. Green algae showed higher concentration of Chl a, b, total chlorophyll Chl a:b ratio, and carbohydrates content compared to red algae; whereas, red algae accumulated more carotenoids, phycocyanin, phycoerythrin, and protein compared to green algae. Moreover, low levels of hydrogen peroxide and TBARS were exhibited in red algae G. salicornia and D. simplex, however, proline, glycine betaine, and activities of antioxidant enzymes were high, showing strong defense system than the green algae.

Menaa et al. (2021) [38] investigated the bioactive compounds for nanodrugs derived from marine algae. The main compounds from algae are the nutraceuticals, which can be extracted and purified for nanotheranostic purposes. Algal extracts can be utilized for stabilizing/capping and reducing the synthesis of thermodynamically stable nanoparticles (NPs). Varieties of nanotherapeutics have been synthesized through physical, chemical, and biological processing. Marine algae are a promising source of lead theranostics compounds and are important for the development of nanotheranostics, which enhance the drug efficacy and safety [38]. Marine algae are considered as biofactories for the nanomaterials as they are easy to handle, capable to absorb and accumulate inorganic metallic ions, cost-effective, and eco-friendly for rapid, healthier synthesis of nanoparticles for various therapies.

DNA fingerprinting is a promising tool for species identification and can be solution for many errors occurred during morphological taxonomy as it requires only a small amount of tissue. To conserve the biodiversity, DNA fingerprinting could also be used for the identification of various invasive and endangered species. DNA fingerprinting is also used for the recognition of high-yielding agar strains of algae as well as for the identification of cryptic species. Alshehri et al. (2021) [39] performed the molecular characterization of some selected algal species (collected from the Gulf of Aqaba) through protein banding pattern and ISSR markers and identified eight algae, namely, Padina pavonica, Turbinaria gracilis, Carpomitra costata, Pterocladiella capillacea, Cladostephus spongiosus, Ulva lactuca, Sporochnus comosus, and Sargassum muticum. The study showed that ISSR marker is more effective than protein banding pattern to measure algal diversity at genetic level. The complied data reflect that the algal biodiversity work is highly reported at Haql shore, whereas the Umluj shore is least explored. The maximum work is about the seasonal dynamics and its floral or faunal density relationship. In all studies, Padina pavonia was the common algal species reported at Tabuk shoreline. The list of algae reported from Tabuk region is summarized in Table 1. Algae are very popular for their high ecological and commercial demand. The most important role of algae to our atmosphere and well-being is the generation of oxygen through photosynthesis and as a food for the marine organisms. They are the producer in the aquatic environment. According to an estimate, the worldwide turnover of the seaweed industry is about USD 10 billion per year. Seaweeds have a number of human applications; the principal use of seaweeds as a source of human food and as a source of gums (phycocollides). Phycocolloides like agar agar, alginic acid and carrageenan are primarily constituents of brown and red algal cell walls and are widely used in food industry to thicken a variety of foods (soy milk, chocolate milk, ice cream, yogurt, soups, salad dressings, jellies, etc.) and in molecular biology lab. Marine macroalgae have been used as foods, especially in China and Japan, and crude drugs for treatment of many diseases such as iodine deficiency (goiter, Basedow’s disease, and hyperthyroidism). Marine algae are the richest source of bioactive nutraceuticals such as antioxidants, pigments, carbohydrates, proteins, minerals, and fatty acids. Moreover, it can be used as a source of fodder, in fish farming, and as a fertilizer [36,41].

2.2. Floral Biodiversity (Angiosperms)

The available literature on floristic diversity of Tabuk region from the last decades (Table 2) mainly focused on their ecological and environmental parameters [1,3,8,18,42,43,44,45,46,47,48]. In the past two decades, Rajasab (2011) [49] carried out the pioneering work in Tabuk region flora. He presented a pictorial guide to the plant diversity of Tabuk region with the description on their traditional uses. The book comprised of three different sections. The first section was on species description, ethno-botanical, and Medicinal uses; the second on plant communities; and the third on plant biodiversity of Tabuk region. In Section I, the author has provided photographs of 115 plant species along with the information on their traditional uses as medicine, food, fodder, agriculture, and horticulture. In Section II, the plant communities in different areas of Tabuk region were described with the help of images of 109 species. Section III contains a list of 198 plant species of 52 families from eight diverse habitats of Tabuk region.

Table 2. List of Angiosperms Reported from Tabuk Region of KSA.

S. No.	Name of plant	Family	Occurance (Reported from)	References
1.	Artemisia judaica	Asteraceae	Tabuk-Jordan Road	Abbas et al., 2017 [50]
2.	Lavandula pubescens	Lamiaceae	Tabuk-Jordan Road	Ansari et al., 2014 [51]
3.	Aizoon canariense L.	Aizoaceae	Ras Hemaid–Duba, Umluj, Alwajh	Moawed & Ansari, 2015 [8]
4.	Hyphaene thebaica (L.) M art.	Arecaceae
5.	Calotropis procera (Aiton)	Asclepediaceae
6.	Leptadenia pyrotechnica Forssk	Apocynaceae
7.	Pergularia tomentosa L.	Apocynaceae
8.	Asphodelus tenuifolius (Cav.)	Asphodelaceae
9.	Anthemis melampodina Delile	Asteraceae
10.	Artemisia herba-alba Asso.
11.	Artemisia judaica L.
12.	Echinops viscosus DC.
13.	Iphiona scabra DC.
14.	Launaea procumbens (Roxb.)
15.	Picris cyanocarpa Boiss
16.	Picris longirostris Sch.Bip.
17.	Pulicaria incisa (Lam.) DC.
18.	Avicennia marina (Forssk.) Vierh.	Avicenniaceae
19.	Heliotropium curassavicum L.	Boraginaceae
20.	Heliotropium crispum Desf.
21.	Heliotropium europaeum L.
22.	Heliotropium ramosissimum (Lehm.) DC.
23.	Anastatica hierochuntica L.	Brassicaceae
24.	Diplotaxis acris (Forssk.) Boiss.
25.	Diplotaxis erucoides (L.) DC.
26.	Farsetia burtoniae Oliv.
27.	Morettia parviflora Boiss.
28.	Malcolmia crenulata (DC.) Boiss
29.	Zilla spinosa (L.) Prantl
30.	Cleome amblyocarpa Barratte & Murb	Cleomaceae
31.	Polycarpaea robbairea (Kunze) Greuter & Burdet.	Caryophyllaceae
32.	Sclerocephalus arabicus Boiss.
33.	Spergularia bocconei (Scheele) Graebn
34.	Anabasis setifera Moq	Amaranthaceae (Chenopodiaceae)
35.	Halocnemum strobilaceum (Pall.) Bieb
36.	Haloxylon persicum Bunge ex. Boss
37.	Haloxylon salicornicum (Moq.) Bunge ex Bioss
38.	Salsola cyclophylla Baker
39.	Salsola villosa Schult
40.	Convolvulus buschiricus Bornm	Convolvulaceae
41.	Citrullus colocynthis (L.) Schrad.	Cucurbitaceae
42.	Cucumis prophetarum L.
43.	Chrozophora tinctoria (L.) A. Juss	Euphorbiaceae
44.	Euphorbia retusa Forssk
45.	Acacia ehrenbergiana Hayne	Fabaceae
46.	Acacia tortilis (Forssk.) Hayne subsp. raddiana (Savi)
47.	Acacia tortilis (Forssk.) Hayne subsp. tortilis (Savi) B
48.	Indigofera arabica Jaub. & Spach
49.	Lotus lanuginosus Vent
50.	Prosopis farcta (Banks & Sol.) J.F. Macbr
51.	Retama raetam subsp. raetam (Forssk.) Webb.
52.	Senna italica Mill.
53.	Erodium laciniatum (Cav.) Willd.	Geraniaceae
54.	Monsonia nivea (Decne.) Webb	Geraniaceae
55.	Muscari tenuiflorum Tausch	Hyacinthaceae
56.	Lavandula coronopifolia Poir.	Lamiaceae
57.	Asparagus horridus L.	Liliaceae
58.	Orobanche cernua Loefl.	Orobanchaceae
59.	Glaucium arabicum Hebrew	Papaveraceae
60.	Linaria haelava (Forskl) F.G. Dietr.	Plantaginaceae
61.	Panicum turgidum Forssk.	Poaceae
62.	Pennisetum divisum (Forssk. ex J.F.Gmel.) Henrard
63.	Phragmites australis (Cav.) Trin. ex Steud.
64.	Stipa hohenackeriana Trin. & Rupr
65.	Schismus arabicus Nees.
66.	Caylusea hexagyna (Forssk.) M. L. Green	Resedaceae
67.	Ochradenus baccatus Del.
68.	Reseda arabica Boiss.
69.	Reseda decursiva Forssk
70.	Reseda muricata C. Presl
71.	Salvadora persica (L.) Garcin	Salvadoraceae
72.	Kickxia scoparia (Spreng.) kunkel.	Scrophulariaceae
73.	Hyoscyamus muticus L.	Solanaceae
74.	Lycium shawii Roem.
75.	Tamarix aphylla (L.) Karsten	Tamaricaceae
76.	Forsskaolea tenacissima L.	Urticaceae
77.	Fagonia bruguieri DC.	Zygophyllaceae
78.	Fagonia indica Burm.
79.	Seetzenia lanata (Willd.) Bullock
80.	Tribulus terrestris L.
81.	Tribulus macropterus Boiss.
82.	Zygophyllum coccineum L.
83.	Zygophyllum simplex L.
84.	Cymodocea rotunda	Cymodoceaceae	HaqL.	Ansari et al. 2021 [52]
85.	Thalassodendron ciliatum
86.	Thalassia hemprichii	Hydrocharitaceae
87.	Halophila stipulacea
88.	Aizoon canariense	Aizoaceae	Tayma	Al-Qahtani 2018 [46]
89.	Artemisia seiberi	Asteraceae
90.	Morettia parviflora	Brassicaceae
91.	Oxalis corniculata
92.	Setaria viridis
93.	Salsola imbricate	Amaranthaceae
94.	Allium sinaiticum Boiss.	Alliaceae	Harrat ArRahah	Fakhry & El-Kenany 2019 [48]
95.	Astragalus collenettiae I.C. Hedge & D.Podl.	Fabaceae
96.	Aizoon canariense L.	Aizoaceae
97.	Allium sinaiticum Boiss.	Alliaceae
98.	Ferula communis L.	Apiaceae
99.	Ferula ovina Boiss.	Apiaceae
100.	Gomphocarpus sinaicus Boiss.	Asclepiadaceae
101.	Asphodelus tenuifolius Cav.	Asphodelaceae
102.	Anthemis deserti (Boiss.) Eig
103.	Cymbolaena griffithii (A.Gray) Wagenitz	Asteraceae
104.	Artemisia inculta Delile
105.	Artemisia judaica L.
106.	Artemisia scoparia Waldst.& Kit.
107.	Asteriscus graveolens (Forssk.) Less.
108.	Asteriscus hierochunticus (Michon)Wiklund
109.	Atractylis carduus (Forssk) C.Chr.
110.	Calendula tripterocarpa Rupr.
111.	Centaurea eryngioides Lam.
112.	Centaurea pseudosinaica Czerep.
113.	Centaurea sinaica DC.
114.	Cymbolaena griffithii (A.Gray)Wagenitz
115.	Echinops glaberrimus DC.
116.	Echinops polyceras Boiss.
117.	Echinops viscosus DC.
118.	Filago desertorum Pomel
119.	Ifloga spicata (Forssk.) Sch.Bip.
120.	Koelpinia linearis Pall.
121.	Launaea angustifolia (Desf.) Kuntze
122.	Launaea capitata (Spreng.) Dandy
123.	Picris asplenioides L.
124.	Reichardia tingitana (L.) Roth
125.	Scorzonera schweinfurthii Boiss
126.	Senecio glaucus L.
127.	Tripleurospermum auriculatum (Boiss.)Rech.f.
128.	Anchusa milleri Spreng.	Boraginaceae
129.	Arnebia decumbens (Vent.)Coss.& Kralik
130.	Arnebia hispidissima (Lehm.) DC.
131.	Echiochilon fruticosum Desf.
132.	Echium angustifolium Mill
133.	Lappula sinaica (DC.) Asch. & Schweinf.
134.	Microparacaryum intermedium (Fresen.) Hillger & Podlech
135.	Aethionema carneum (Banks & Sol.) B. Fedtsch.	Brassicaceae
136.	Alyssum marginatum Steud. ex Boiss.
137.	Brassica cretica Lam.
138.	Capsella bursa-pastoris (L.) Medik.
139.	Diplotaxis harra (Forssk.) Boiss.
140.	Eremobium aegyptiacum spp. Lineare (Delile) Zohary
141.	Isatis lusitanica L.
142.	Matthiola longipetala (Vent.) DC.
143.	Morettia canescens Boiss.
144.	Neotorularia torulosa (Desf.) Hedge &J.Leonard
145.	Schouwia purpurea (Forssk.) Schweinf.
146.	Sisymbrium irio L.
147.	Sisymbrium loeselii L.
148.	Zilla spinosa (L.) Prantl
149.	Cerastium dichotomum L.	Caryophyllaceae
150.	Herniaria hirsuta L.
151.	Minuartia picta (Sibth. &Sm.) Bornm.
152.	Silene arabica Boiss.
153.	Silene colorata Poir.
154.	Silene linearis Decne.
155.	Silene hussonii Boiss
156.	Agathophora alopecuroides (Delile) Fenzl ex.Bunge	Amaranthaceae
157.	Cornulaca monacantha Delile
158.	Haloxylon salicornicum (Moq.)Boiss.
159.	Noaea mucronata (Forssk.) Asch. & Schweinf
160.	Salsola lachnantha (Botsch.) Botsch.
161.	Salsola tetrandra Forssk
162.	Helianthemum lippii (L.) Dum.Cours.	Cistaceae
163.	Helianthemum salicifolium (L.)Mill.
164.	Colchicum ritchii R.Br.	Colchicaceae
165.	Citrullus colocynthis (L.) Schrad.	Cucrbitaceae
166.	Scabiosa porphyroneura Blakelock	Dipsacaceae
167.	Euphorbia retusa Forssk	Euphorbiaceae
168.	Euphorbia serpens Kunth
169.	Acacia gerrardii var. najdensis Zohary	Fabaceae
170.	Astragalus bombycinus Boiss.
171.	Astragalus caprinus L.
172.	Astragalus collenettiae I.C. Hedge & D.Podl.
173.	Astragalus kahiricus DC.
174.	Astragalus palaestinus Eig
175.	Astragalus schimperi Boiss.
176.	Astragalus spinosus (Forssk) Muschl.
177.	Astragalus tribuloides var. minutus (Boiss.) Boiss.
178.	Medicago laciniata (L.) Mill.
179.	Retama raetam (Forssk.) Webb Ph PerenniaL.
180.	Trigonella stellata Forssk.
181.	Erodium crassifolium L’Her.	Geraniaceae
182.	Erodium laciniatum var. glanuloso-pilosum Viern.
183.	Erodium oxyrhynchum M.Bieb.
184.	Erodium oxyrhynchum var. bryoniifolium (Boiss) Schonb.Tem
185.	Dipcadi erythraeum Webb. & Berth.	Hyacinthaceae
186.	Leopoldia tenuiflorum (Tausch) Heldr.
187.	Iris postii Mouterde	Iridaceae
188.	Ixiolirion tataricum (Pall.) Herb.	Ixioliriaceae
189.	Lavandula pubescens Decne	Lamiaceae
190.	Salvia palaestina Benth.
191.	Teucrium leucocladum Boiss.
192.	Teucrium polium L.
193.	Bellevalia flexuosa Boiss.	Liliaceae
194.	Gagea reticulata (Pall.)Schult. & Schult. f.
195.	Tulipa biflora Pall.
196.	Malva parviflora L.	Malvaceae
197.	Fumaria parviflora Lam.	Papaveraceae
198.	Glaucium arabicum Fresen
199.	Hypecoum pendulum L.
200.	Roemeria hybrida ssp.dodecandra (Forssk.) Maire
201.	Plantago amplexicaulis Cav.	Plantaginaceae
202.	Plantago ciliata Desf.
203.	Plantago ovata Forssk
204.	Aegilops kotschyi Boiss.	Poaceae
205.	Bromus tectorum L.
206.	Cutandia memphitica (Spreng.)K.Richt.
207.	Cynodon dactylon (L.) Pers.
208.	Eremopyrum confusum Melderis
209.	Hordeum murinum spp. glaucum (Steud.) Tzvelev
210.	Stipagrostis raddiana (Savi) de Winter
211.	Emex spinosa (L.) Campd.	Polygonaceae
212.	Polygonum palaestinum Zohary
213.	Rheum palaestinum Feinbr
214.	Rumex pictus Forssk
215.	Rumex vesicarius L.
216.	Adonis dentata Delile	Ranunculaceae
217.	Oligomeris linifolia (Vahl.) Macbr	Resedaceae
218.	Linaria haelava (Forssk.) Delile	Scrophulariaceae
219.	Veronica beccabunga L.
220.	Hyoscyamus desertorum	Solanaceae
221.	Hyoscyamus muticus L.
222.	Hyoscyamus pusillus L.
223.	Hyoscyamus aureus L.
224.	Solanum nigrum L.
225.	Parietaria alsinifolia Delile	Urticaceae
226.	Valerianella szovitsiana Fisch. & C.A. Mey	Valerianaceae
227.	Fagonia boveana (Hadidi)	Zygophyllaceae
228.	Fagonia tenuifolia Hochst. & Steud. ex Boiss.
229.	Fagonia tristis Sickenb.
230.	Peganum harmala L.
231.	Tribulus pentandrus Forssk.
232.	Aerva javanica	Amaranthaceae	Al-Wadi Al-akhder	Al-Ghanem et al., 2020 [43]
233.	Leptadenia pyrotechnica	Asclepiedaceae
234.	Calotropis procera
235.	Rhanterium epapposum	Asteraceae
236.	Artemisia judaica
237.	Artemisia monosperma
238.	Artemisia sieberi
239.	Pulicaria undulate
240.	Heliotropium bacciferum	Boraginaceae
241.	Salsola tetrandra	Amaranthaceae (Chenopodiaceae)
242.	Suaeda vermiculata
243.	Haloxylon salicornicum
244.	Atriplex leucoclada
245.	Salsola villosa
246.	Salsola volkensii
247.	Helianthemum lippii	Cistaceae
248.	Helianthemum aegyptiacum
249.	Citrullus colocynthis	Cucurbitaceae
250.	Acacia nilotica	Fabaceae
251.	Retama raetam
252.	Astragalus spinosus
253.	Acacia ehrenbergiana
254.	Alhagi maurorum
255.	Salvia spinosa	Lamiaceae
256.	Salvia aegyptiaca	Lamiaceae
257.	Teucrium oliverianum	Lamiaceae
258.	Zilla spinosa	Brassicaceae
259.	Tamarix nilotica	Tamaricaceae
260.	Ducrosia anethifolia	Umbelliferae
261.	Zygophyllum coccineum	Zygophyllaceae
Plant Species of Medicinal Importance in Tabuk Region
262.	Ferula ovina Boiss.	Apiaceae	Tabuk City, Tayma, Haql, Duba, Alwajh and Umluj	Alharbi 2017 [3]
263.	Rhazya stricta Decne.	Apocynaceae
264.	Phoenix dactylifera L.	Arecaceae
265.	Calotropis procera Aiton.	Asclepiadaceae
266.	Pergularia tomentosa L.	Arecaceae
267.	Achillea fragrantissima	Asteraceae
268.	Anvillea garcinii DC.	Asteraceae Avicenniaceae
269.	Artemisia sieberi Bsser
270.	Artemisia judaica L.
271.	Artemisia monosperma Del.
272.	Asteriscus graveolens Forssk.
273.	Reichardia tingitana L.
274.	Sonchus oleraceus L.
275.	Avicennia marina Forssk.
276.	Anastatica hierochuntica L.	Brassicaceae
277.	Capsella bursa- pastoris L.	Brassicaceae Capparaceae
278.	Brassica rapa L.
279.	Capparis cartilaginea Decne
280.	Capparis deciduas Forssk	Capparaceae Cleomaceae
281.	Capparis spinose L.
282.	Cleome amblyocarpa
283.	Cleome arabica Wall	Cleomaceae
284.	Atriplex halimus L.	Amaranthaceae (Chenopodiaceae)
285.	Atriplex leucoclada Boiss.	Amaranthaceae (Chenopodiaceae) Convolvulaceae
286.	Chenopodium album L.
287.	Bassia muricata L.
288.	Cornulaca monacantha
289.	Haloxylon salicornicum Mog
290.	Traganum nudatum Delile.
291.	Convolvulus arvensis L.
292.	Citrullus colocynthis L.	Cucurbitaceae
293.	Cynomorium coccineum L.	Cyomoriaceae
294.	Chrozophora tinctoria L.	Euphorbiaceae
295.	Acacia tortilis Forssk.	Fabaceae
296.	Alhagi graecorum Boiss.	Fabaceae Fumariaceae
297.	Astragalus spinosus Forssk.
298.	Astragalus tribuloides Del.
299.	Melilotus indica L.
300.	Cassia holosericea Fres.
301.	Cassia italic (Mill) Lam
302.	Retama raetam Forssk.
303.	Trigonella stellata Forssk.
304.	Fumaria parviflora Lam.
305.	Lavandula pubescens Decne	Lamiaceae
306.	Mentha longifolia L.	Lamiaceae Liliaceae
307.	Salvia lanigera Poir
308.	Teucrium polium L.
309.	Thymus vulgaris L.
310.	Colchicum ritchii R.Br.
311.	Malva parviflora L.	Malvaceae
312.	Ficus cordata L.	Moraceae
313.	Ficus palmate Forssk.	Moraceae
314.	Cistanche phelypaea L.	Orobanchaceae
315.	Plantago amplexicaulis Cav.	Plantaginaceae
316.	Plantago afra L.	Plantaginaceae Poaceae
317.	Plantago boissieri Hausskn &Bornm.
318.	Plantago ciliata Desf.
319.	Plantago coronopus L.
320.	Plantago major L.
321.	Plantago lanceolata L.
322.	Plantago ovata Forssk.
323.	Cynodon dactylon L.
324.	Phragmites australis Cav.	Poaceae
325.	Calligonum comosum L.	Polygonaceae
326.	Emex spinosus L.	Polygonaceae Portulacaceae
327.	Rumex vesicarius L.
328.	Portulaca oleracea L.
329.	Ochradenus baccatus Del.	Resedaceae
330.	Oligomeris linifolia Vahl	Resedaceae
331.	Ziziphus spina-christi L.	Rhamnaceae
332.	Hyoscyamus muticus L.	Solanaceae
333.	Lycium shawii L.	Solanaceae Tamaricaceae
334.	Solanum nigrum L.
335.	Tamarix nilotica Bge.
336.	Typha domingensis Pers.	Typhaceae
337.	Fagonia bruguieri DC.	Zygophyllaceae
338.	Peganum harmala L.	Zygophyllaceae
339.	Tribulus terrestris L.
340.	Zygophyllum album L.
341.	Zygophyllum coccineum L.
342.	Zygophyllum simplex L.

Many authors [45,47,50] conducted the study of biodiversity in relation to the regimes of Tabuk environment. The Tabuk region is known for its extremely variable environment where the temperature varies from extreme low to extreme high. These temperature regimes have a profound effect on growth, morphology, physiology, and biochemistry of the plants. Ansari et al. (2014) [51] studied the growth of Lavandula pubescens in relation to the temperature variations, and observed active role of CAT, POD, and SOD in plants to cope with this abiotic stress. Abbas et al. (2017) [50] also observed the ecological variations and an active role of heat shock protein in Artemisia judaica L. to the same abiotic stress. The investigations of Ansari et al. (2014) [51] and Abbas et al. (2017) [50] suggest that April and October are favorable for growth, development, and medicinal uses of plants reported from this region. Recently, Ansari et al. (2021) [52] reported five common sea grass species, namely, Cymodocea rotundata, Halodule pinifolia, Thalassodendron ciliatum, Halophila stipulacea, and Thalassia hemprichii, from the Red Sea coast at Haql in Tabuk province. A quantitative analysis, in terms of frequency, density, abundance, and dominance of sea grass diversity was measured. The authors reported a marked difference in the quantitative parameters of sea grass diversity within the species, as well as on different study sites.

However, Mutairi et al. (2017) [45] focused on the influence of environmental factors on the taxonomic diversity of plant species in the arid region of Tabuk, which are characterized by a particular floristic composition, and their diversity. Average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Λ+) were the two diversity indices used to calculate the effect of the environment and limiting environmental factors. Anthropogenic factors (woodcutting, pasture, and urbanization) are some of the important factors which significantly affect the floristic diversity [45]. In another study, Al-Mutairi et al. (2016) [4] discussed the floristic diversity and phytogeographical distribution of plant species along the four Red Sea coastal sites at Sharma, Alqan, Al-Lwaz Mountains, and Alzetah of Tabuk province. The author reported 96 plant species belonging to 75 genera and 38 families, out of which, there were 34 dicots and 4 monocots. Most of the species were from the family Asteraceae (12.5%), followed by Fabaceae (10.42%), Zygophyllaceae (6.25%), and Lamiaceae (5.21%). In terms of life form spectrum, most of the species were theorphytes (37%), followed by chamaephytes (32%), geeophytes (13%), hemicryptophytes (10%), and Phanerophytes (8%). The chorological analysis of the recorded species indicated the predominance of monoregional taxa in this region. Recently, Al Mutairi (2022) [1] studied the plant diversity in five places of Tabuk region along with spatial variables, soil physical and chemical variables. The author reported 163 species of plants belonging to 124 genera of 41 families. The Aldesah site recorded the highest value of beta diversity followed by Sharma. There was no pronounced influence of spatial variables was observed on the plant diversity. However, the soil variables (pH, potassium. organic matter and sodium) show a solid possibility in constructing the plant communities.

Moawed and Ansari (2015) [8] studied the wild plant diversity at the coastal areas of Red Sea in Tabuk province. They reported 30 families, 66 genera, and 82 plant species from this region. Family Asteraceae showed highest abundance (9 species), followed by Fabaceae (8 species), Brassicaceae and Zygophyllaceae (7 species), Amaranthaceae (Chenopodiaceae) and Poacea (6 species), Resedaceae (5 species), Boraginaceae (4 species), and Asclepediaceae and Caryophyllaceae (3 species). The chamaephytes and therophytes are the dominating plant life forms, indicating vegetation of typical desert spectrum. There were 32.92% chamaephytes, and 29.27% therophytes; 57.32% were perennial and 42.68% annual species [8]. Al-Qahtani (2018) [46] reported the diversity of weeds species in Citrus farms of Taymma of Tabuk province to find out the invasive species of weeds, which are the critical problem of agroecosystem and a major cause of huge economic losses. They have identified 36 weed species belonging to 20 families from the citrus farms of Taymma. Out of all the reported invasive species, Izoon canariense, Artemisia seiberi, Morettia parviflora, Oxalis corniculata, Setaria viridis, and Salsola imbricata were dominant over these citrus farmlands belonging to the dominant families Poacea, Asteraceae, Brassicaceae, and Amaranthaceae (Chenopodiaceae) [46]. The Harrat ArRahah is located in the southern area of Tabuk, which is a solidified lava area. Fakhry and Al-Kenany (2019) [48] reported 135 species belonging to 99 genera and 34 families from the study area. Families Asteraceae, Brassicaceae, and Fabaceae contributed about 38% of total species. Fourteen species (10%) were recognized as endangered, Iris postii and Tulipa biflora were reported as rare endangered species. Although Rheum palaestinum in the flora of Saudi Arabia is recorded as an extinct species, three individuals were recorded in the study area. Astragalus collenettiae was the only endemic species recorded from this area [48].

The floristic diversity and perennial vegetation analysis was undertaken by Al-Ghanem et al. (2020) focused on Wadi AL-Akhder the. The author reported 30 species belonging to 23 genera and 15 families form the study sites. Amaranthaceae (Chenopodiaceae) contributed 20%, followed by Asteraceae and Fabaceae (16.76%), Lamiaceae (10%), and Cistaceae and Asclepiedaceae (6.76%). There was prevalence of chamaephytes (56.67%), followed by Therophytes (20%), Phanerophytes (16.67%), and Hemicryptophyte (6.76%) [43]. Alharbi (2017) reported 81 traditional and medicinal plant species belong to 30 families which are commonly used for treatment of digestive tract diseases and parasites. Nine species were reported from the family Febaceae, eight species each from Asteraceae and Plantagiaceae, and six species from Zygophyllaceae [44].

Among the studied literature, we found 227 species of 157 genus were identified that belongs to 45 families of angiosperms. On comparing the above data with the endangered list of Flora of KSA (2022) [53], we recorded 12 endangered species of plants from Tabuk region, namely, Allium sinaiticum, Astragalus collenettiae, Cerastium dichotomum, Cymbolaena griffithii, Glaucium arabicum, Leopoldia tenuiflorum, Minuartia picta, Salsola lachnantha, Salvia palaestina, Tulipa biflora, Valerianella szovitsiana, and Veronica beccabunga.

3. Animal Biodiversity of Tabuk Region

The presence of different kinds of animals in a geographical region is very important for a balanced environment and a functional ecosystem. In the Tabuk region, studies are conducted to identify the biodiversity of insects, snails, fishes, amphibians, reptiles, birds, and mammals in different seasons and year [18,54,55,56,57,58]. In the following passage, a comprehensive account is presented to draw a baseline data from the published reports.

3.1. Biodiversity of Terrestrial Animals including Amphibians

Mohammed (2012) [57] reported the animal diversity on agricultural and non-agricultural land areas in different seasons of a year. The author selected a 500 m × 500 m land for this study and collected data using various traps. Several animal species were trapped, identified, and described, and their biodiversity was measured using diversity indices. Relative abundance and species richness was also determined for animal species belonging to different classes. Further, the effect of temperature on animal diversity was studied and animal community was studied using diversity index H =− ΣPi (LnPi). The study showed that H of all classes was 2.02; diversity rate for birds (72 species) H = 3.05, mammals (10 species) H = 1.5, reptiles (18 species) H = 2.3, amphibians (7 species) H =1.4, and freshwater fish (3 species) H = 0.92. Among the invertebrates, eight species of scorpions and five species of spiders, H = 1.78 and H = 0.9, respectively, and insects (93 species) H = 3.86 were recorded [57].

Among all the animal species, insect diversity was dominant throughout the year. However, it showed its maximum in the summer and minimum in the winter. Some reptile species Stenodactylus arabicus and Stenodactylus grandiceps, were highly abundant [57]. Among the mammal species, Gerbillus nanus was most abundant, whereas Spalax leucodon was rarely found. A convergent abundance of spiders was recorded, except the Pholcus phalangioide. Scorpions also showed convergent abundance, except Leiurus quinquestraitus and Compsobuthus arabicus. There were 21% amphibians, 25% fishes, 3% insects, and 1% birds among all the species studied. The study recommends that more work has to be conducted to measure the biodiversity and abundance of different animal species in various regions of the Kingdom of Saudi Arabia in general and Tabuk region in particular [57].

The National Commission for Wildlife Conservation and Development, Riyadh, Saudi Arabia NCWCD (2000) [59] reported 35 species of mammal, 37 species of reptiles, and 167 species of bird (82 resident and 85 migratory birds) from Tabuk region (Table 3 and Table 4). They surveyed the local animal markets in the Tabuk region to investigate the trade of wildlife species. The study reported the illegal trade of various animal species in Tabuk region which reveals the violation of conservation of biodiversity [18]. In their study, it was recorded that most of the traded animals were bird species (97%) followed by reptiles and mammals (2% and 1%, respectively). Some stuffed animals were also available in the market; however, the majority of specimens (98%) were living. There were 22 bird species that belongs to 12 families were recorded in the market. The highest traded species (65%) among the birds was Quail Coturnix coturnix, as it is easy to capture. Only one specimen each of Turquoise-fronted Amazon (Amazona aestiva), Yellow-crowned Amazon (A. ochrocephala), Blue-and-yellow Macaw (Ara ararauna), Greater Rhea (Rhea americana), and the native Griffon Vulture (Gyps fulvus) and Osprey (Pandion haliaetus) were also found in the animal market surveyed [18].

Table 3. Avians (birds) reported from the Tabuk region.

No.	Species	Common Name	Occurrence (Reported from)	Source of Information/Reference
1	Ciconia nigra	Black Stork	Tabuk region	Viv Wilson (2015) [60]
2	Aquila nipalensis	Steppe Eagle	Tabuk region	Viv Wilson (2015) [60]
3	Aquila heliacal	Eastern Imperial Eagle	Tabuk region	Viv Wilson (2015) [60]
4	Sula leucogaster	Brown Booby	Islands close to Al Wajh and Umluj (Riykhah island)	Shobrak and Aloufi (2014) [61]
5	Butorides striatus	Striated Heron	Islands close to Al Wajh and Umluj
6	Egretta gulari	Western Reef Heron	Islands close to Al Wajh and Umluj (Nabageyah, and Al Uwandiyah islands).
7	Ardea purpurea	Purple Heron	Islands close to Al Wajh and Umluj (Ber-reem island The bird not seen but suspected nests)
8	Pandion haliaetus	Osprey	Islands close to Al Wajh and Umluj (Ber-reem, Riykhah and Mezabeyah islands)
9	Falco concolo	Sooty Falcon	Islands close to Al Wajh and Umluj (Ber-reem, Mardunah, and Riykhah islands)
10	Charadrius alexandrines	Kentish Plovers	Islands close to Al Wajh and Umluj (Harr and Sheikh Marbat islands)	Shobrak and Aloufi (2014) [61]
11	Dromas ardeola	Crab Plover	Islands close to Al Wajh and Umluj (Sheikh Marbat, and Attaweel islands)
12	Ichthyaetus hemprichii	Sooty Gull	Islands close to Al Wajh and Umluj (Riykhah island)
13	Larus leucophthalmus	White-eyed Gull	Three islands of Umluj Al Wajh Bank
14	Sterna caspia	Caspian Tern	All islands of Umluj
15	Sterna bergii	Swift Tern	Islands close to Al Wajh and Umluj (Sheik Marbat sland)
16	Thalasseus bengalensis	Lesser Crested Tern	Islands close to Al Wajh and Umluj (Al Nabageyah Island)
17	Sterna repressa	White-cheeked tern	Islands close to Al Wajh and Umluj (Sheik Marbat sland)
18	Onychoprion anaethetus	Bridled Tern	Islands and Bank of Al Wajh
19	Sternula saundersi	Saunders’s Tern	Islands close to Al Wajh and Umluj (Sheik Marbat sland)

Table 4. Mammals reported from the Tabuk region.

No	Species	Common Name	Occurrence (Reported from)	References
Carnivorous
1	Mustelid, Mellivora capensis Schreber, 1776	Honey Badger	-Tayma	Aloufi and Amr (2018) [54] Mallon and Budd (2011) [62]
2	Felines, Felis margarita Loche, 1858	Sand Cat	Haqel Rowafah, Al Zetah	Aloufi and Amr (2018) [54]
3	Felines, Panthera pardus Linnaeus, 1758)	Leopard (Not recorded in the study but photographed by a local in 1952)	Shar Mountain
4	Canids Canis lupus Linnaeus, 1758	Grey Wolf		Aloufi and Amr (2018) [54] Mallon and Budd (2011) [62]
5	Canids Vulpes cana Blanford, 1877	Blanford’s fox	Bajdah	Aloufi and Amr (2018) [54]
6	Canids Vulpes vulpes (Linnaeus, 1758)	Red fox	El Zawiah Al Qelebah Tabuk (Damaj and Tadco Farms) Haqel Bajdah Al Sero Shegry Wadi Al Akhdher Al Zetah At-Tubayg Reserve
7	Canids Vulpes zerda (Zimmermann, 1780)	Fennec Fox		Mallon and Budd (2011) [62]
8	Hyaenid Hyaena hyaena (Linnaeus, 1758)	Striped Hyaena	Abu Rakah Bajdah Wadi Al Gshabreah Bedeaa Al Disah Geal Gumailah Haqel Alagan Harat Alrahah	Aloufi and Amr (2018) [54] Mallon and Budd (2011) [62]

The Rock Hyrax (Procavia capensis) and Spur-thighed Tortoise (Testudo graeca) were the most prevalent mammal and reptilian species in Tabuk market, respectively. Among the surveyed animals, as per the International Union for Conservation of Nature (IUCN), seven species were identified as threatened with extinction and few were Red Listed animal species, critically endangered reptile species, endangered bird species and vulnerable species. There were also 20 CITES-listed species recorded form the area of the study [18].

In another study, Aloufi, et al. (2016) reported 10 bat species (Table 5) based on their echolocation calls. One new species (Barbastella leucomelas) was identified and added to the list of bat species of Saudi Arabia and Arabian Peninsula. Moreover, occurrence of R. aegyptiacus was observed expanding the distribution range of bat species in northwestern part of Saudi Arabia [55]. The diversity and distribution of bats in Saudi Arabia is still unexplored. Further GIS studies can provide more authentic data [63,64,65].

Table 5. Bats reported from the Tabuk region.

No.	Scientific Name	Common Name	Occurrence (Reported from)	References
1	Rousettus aegyptiacus (Geoffroy, 1810)	Egyptian rousette (Egyptian fruit bat)	Tabuk city Tayma Al Disah	Aloufi et al. (2016) [55]
2	Rhinopoma cystops Thomas, 1903	Egyptian mouse-tailed bat	Sharma
3	Rhinolophus clivosus Cretzschmar, 1828	Geoffroy’s horseshoe bat	Tabuk city
4	Asellia tridens (Geoffroy, 1813)	Trident leaf-nosed bat, Geoffroy’s Trident Leaf-nosed Bat	Al Bedea’a
5	Barbastella leucomelas (Cretzschmar, 1830)	Asian barbastelle	Alagan-Algtar
6	Eptesicus bottae (Peters, 1869)	Botta’s Serotine	Alagan-Algtar
7	Hypsugo ariel (Thomas, 1904)	The desert pipistrelle	Tabuk city
8	Otonycteris hemprichii Peters, 1859	Desert Long-eared Bat	That Al Haji
9	Plecotus christii Gray, 1838	Christie’s big-eared bat	Albogaz Tunnel
10	Tadarida teniotis (Rafinesque, 1814)	European free-tailed bat	Tabuk city

Aloufi and Amr (2018) studied the diversity of carnivores from Tabuk Province from 2010 to 2017. Information was collected using camera traps and live traps, and through direct observations. Seven carnivore species representing four families were recorded. There were three felines, Felis margarita and Panthera pardus nimr; a hyaenid, Hyaena hyaena; a mustelid, Mellivora capensis; and three canids, Canis lupus, Vulpes cana, and Vulpes vulpes. For each species, a list of location was given for its current distribution. Unfortunately, poachers or the local community killed many of the reported species. Killing and hanging of various animal species is common practice in this region [54]. Carnivores are facing many types of threats, such as shooting, trapping, and poisoning [62]. The animal killing shows the level of aggression of poachers or villagers for the carnivores (wolves and hyenas) just as a sign of pride [66]. However, the conflict between humans and wildlife and their coexistence is a global issue [42]. The diversity of carnivores in Saudi Arabia is very poor and requires an immediate action from Ministry of Environment, Water, and Agriculture for their conservation and sustainability of the region [54]. Apart from carnivores, one amphibian and thirty-three reptile species belonging to twelve families (Cheloniidae, Gekkonidae, Agamidae, Chamaeleonidae, Lacertidae, Scincidae, Varanidae, Trogonophidae, Boidae, colubridae, Viperidae, and Elapidae) are also reported form Tabuk region (Table 6). The important part is there were three new species of reptiles (Hemidactylus mendiae, Pseudotrapelus aqabensis, and Phoenicolacerta kulzeri) [67]. The reporting of new species is a good indicator of a functional ecosystem.

Table 6. Amphibian and Reptiles reported from Tabuk region.

No	Species	Common Name	Occurrence (Reported from)	References
1	Ambphibia, Bufo arabicus Heyden, 1827	Arabian toad	Maqna Al Disah Tayma Tayeb ism	Aloufi and Amr (2015b) [67]
2	Reptile, Eretmochelys imbricate (linnaeus, 1766)	Hawksbill sea turtle	Owindyeah island
3	Reptile, Bunopus tuberculatus Blanford, 1874	Bunopus tuberculatus	Tabuk city
4	Reptile, Cyrtopodion scabrum (Heyden, 1827) (In Al Disah)	Rough-tailed gecko, Rough bent-toed gecko, Rough-tailed bowfoot gecko, Common tuberculate ground gecko	Umluj Al Disah
5	Reptile, Hemidactylus flaviviridis Rüppell, 1835	Yellow-belly gecko, or Northern house gecko.	Al Wajh Umluj
6	Reptile, Hemidactylus mendiae Baha el Din, 2005	Yellow-Bellied Gecko	Al Qatar
7	Reptile, Ptyodactylus hasselquistii (Donndorff, 1798)	Common Fan Footed Gecko	Al Wajah Bajdah Al Disah Halat Ammar Al Hisma Qalat Al Mowaileh AlKonah Halat Ammar, Tayeb ism, Harat Al Rahah Tayma
8	Reptile, Pristurus rupestris Blanford, 1874	Blandford’s Semaphore Gecko	Harat Al Hara
9	Reptile, Stenodactylus doriae (Blanford, 1874)	Middle Eastern short-fingered gecko, or Doria’s comb-fingered gecko	Al Zetah, Wadi Al Hemdh
10	Reptile, Pseudotrapelus aqabensis Melnikov, Nazarov, Ananjeva & Disi, 2012		Al Zetah, Al Beda’a,
11	Reptile, Pseudotrapelus sinaitus (Heyden, 1827)	Sinai agama	Hisma Harat Al Rahah Tayma
12	Reptile, Stellagama stellio brachydactyla (Haas, 1951)	Short-Toed Rock Agama	Al Disah Bajdah AlKonah Hisma Harat Al Rahah
13	Reptile, Trapelus flavimaculatus Rüppell, 1835	Yellow-spotted agama	Al Wajh Umluj	Aloufi and Amr (2015b) [67]
14	Reptile, Uromastyx aegyptia microlepis Arnoid, 1980		Sharma Tayma Harat Al Rahah
15	Reptile, Chamaeleo chamaeleon orientalis Parker, 1938		Bajdah Harat Al Rahah
16	Reptile, Acanthodactylus boskianus (Daudin, 1802)	Bosc’s fringe-toed lizard	Harat Al Rahah
17	Reptile, Acanthodactylus opheodurus Arnold, 1980	Arnold’s fringe-fingered lizard, or The snake-tailed fringe-toed lizard	Al Zetah Wadi Al Meyah Bajdah Al Disah
18	Reptile, Acanthodactylus schmidti Haas, 1957	Schmidt’s fringe-fingered lizard, or Schmidt’s fringe-toed lizard	Al Zetah Harat Al Rahah Tayma Hisma
19	Reptile, Mesalina brevirostris Blanford, 1874	Blanford’s short-nosed desert lizard	Umluj
20	Reptile, Ophisops elegans Ménétries, 1832	Snake-eyed lizard	Hisma
21	Reptile, Phoenicolacerta kulzeri ssp.		Al Konah
22	Reptile, Chalcides cf. ocellatus (Forskal, 1775)		Magna
23	Reptile, Trachylepis brevicollis (Wiegmann, 1837)		Qala’at Al Azlam
24	Reptile, Scincus mitranus Anderson, 1871	Eastern skink	Tayma
25	Reptile, Scincus scincus meccensis (Wiegmann, 1837)		Hisma Tayma
26	Reptile, Varanus griseus (Daudin, 1803)	Desert Monitor	Tayma
27	Reptile, Diplometopon zarudnyi Nikolsky, 1907	Zarudny’s worm lizard	Tayma
28	Reptile, Eryx jaculus (linneus, 1758)	Javelin sand boa	Tayma
29	Reptile, Rhagerhis moilensis (Reuss, 1834)	Moila Snake	Tabuk city
30	Reptile, Psammophis schokari (Forskal, 1775)	Schokari Sand Racer	Magna Bajdah
31	Reptile, Spalerosophis diadema cliffordi (Schlegel, 1837)	Diadem Snake Royal Snake	Hisma Wadi Al Meyah
32	Reptile, Cerastes gasperettii gasperettii Leviton & Anderson, 1967	Arabian Horned Viper	Tabuk city Al Zetah Bajdah Tayma
33	Reptile, Echis coloratus Günther, 1878	Painted saw-scaled viper, or Painted carpet viper	Al Beda’a Bajdah Harat Al Rahah
34	Reptile, Walterinnesia aegyptia Lataste, 1887	Desert Cobra	Al Qelebah

3.2. Biodiversity of Aquatic Animals

The aquatic ecosystem is very rich in fauna at various sites of Tabuk region, namely, Haql, Duba, Sharma, Alwajh, Umluj, etc. The relative densities of aquatic fauna in different seasons of Tabuk were determined and correlated with coastal water quality [56]. Lottia limulata, Nerita fulgurans Puncturella longifissa Istiblennius dussumieri and Gerres sp were identified from the coastal sites of the Red Sea. Among all, Lottia limulata was abundant and densely populated at the studied coastal sites in Haql in October 2013, whereas Boleophthalmus was at Duba April 2014 [56]. Coastal eutrophication due to anthropogenic inputs of nutrients showed a direct influence on phytoplankton, zooplanktons, macrophytes, and fish diversity. Dominating algal species is the major characteristic of eutrophic ecosystems which affects the diversity of consumers [68,69].

The Red Sea is rich in biodiversity with large varieties of fish and other marine animals that can be identified through DNA barcoding. DNA barcoding is an effective tool for the species identification and assessment of biodiversity. Several studies have been conducted for the sequence diversity in a ~ 650 bp region near the 5′ region of COI gene (cytochrome c oxidase) which provides strong species level resolution for verification of animal groups, such as birds, springtails, spiders, and fishes [58]. Six fish species, namely, Epinephelus bleekeri, Siganus sutor, Carangoides sp., Scomberomorus commerson, Lutjanus ehrenbergii, and Pristipomoides filamentosus, reported from Red Sea using COI barcode sequence [58]. Further, Rock skipper’s diversity was studied in the coastal waters of the Red Sea [47,70]. The impact of different environmental factors on coastal biodiversity can be measured by determining the density, frequency, and abundance of rock skippers. The reproduction, life cycle, and some specific physiological and behavioral patterns make them important as ecological indicator for coastal biodiversity [56].

In a study by Amr and Alshammari (2012) [71], 29 species of snails were recorded form Arabian Peninsula. One species, Bulinus beccari, was reported from the Hail region. In the Tabuk region, 75 freshwater aquatic habitats (springs, artificial lakes, swamps, streams, ponds, and irrigation canals) were studied in between 2012 and 2014. Eten smarts Global Position System was used; two freshwater snail species (Melanoides tuberculata and Melanopsis buccinoidea) belonging to families Thiaridae and Melanopsidae, respectively, were reported for the first time from six localities of Tabuk region [72]. Moreover, characteristics and distribution of larval habitats of Culex pipiens complex in Tabuk was studied. In total, 116 aquatic habitats were surveyed, 48 were positive for larvae of Culex pipiens L. (76.3%) and Cx. quinquefasciatus (23.7%). Shallow water, mud bottom, and absence of grasses, algae, and predators were the common characteristics of habitats positive for Culex larvae (p < 0.05) [73].

4. Microbial Biodiversity of Tabuk Region

Soil microorganisms are associated soil quality and productivity. The soil microorganisms are very important for the functionality of the ecosystem of a geographical region. The soil fauna and flora are responsible for the decomposition of organic matter and recycling of nutrients. In the Tabuk region, microbial diversity reports are very few and published in past couple of years. The proper mapping still has a long way to go. We are providing a comprehensive account based on available literature. Ghobashy and Helal (2018) [74] studied wild microbial communities, especially in the un-explored areas and reported Bacillus sp. as the most abundant genus. It contributed about 70.4% of the total isolates of soil microbiota. In another study, microbial (fungi and bacteria) diversity and abundance was investigated by Alotaibi et al. (2020) [75] in Sabkha and desert areas of Saudi Arabia. Soil samples from Al-Aushazia lake, AlQasab, AlKasar, Tabuk, Al-Kharj, Al-Madina, Jubail, Taif, and Abqaiq were analyzed for microbial isolation using molecular techniques (PCR and sequencing). On the basis of 18SrDNA sequencing, 203 fungal species belonging to 33 genera were identified [75]. The most common fungi were Fusarium, Alternaria, Chaetomium, Aspergillus, Cochliobolus, and Pencillium. Further, 16S rDNA sequencing revealed 22 bacterial species of two genera, Bacillus and Lactobacillus. The most common bacterial species were Bacillus subtilis and Lactobacillus murinus. Some fungal species, Actinomyces elegans, Fusarium proliferatum, Gymnoascus reesii, and Myzostoma spp., were also isolated, but only from the soil of Al-Aushazia. AlQasab soil had the highest microbial diversity among other areas with abundances of 23.5% and 4.4% of total fungi and bacteria, respectively. The findings of this study reveal that fungal diversity is greater than that of bacteria [75]. In another report, 33 marine bacterial species [76] and Enterobacter sp. [77] were isolated and identified from the coastal environment of Haql. These studies are very significant and help us to understand the microbial habitat ecology and diversity. Further, these studies can be linked to the presence of other organisms in a functional ecosystem and developing a model.

5. Conclusions

Biodiversity defines the variations in living organisms at genetic, species, and ecosystem level at a particular time. Monitoring, assessment, and conservation of biodiversity is the need of the hour and is one of the important global environmental concerns. There are some published reports on the diversity of plants, animal, and microorganisms in the Tabuk Region, but there is still gap in the biodiversity of region and its mapping. In order to create a baseline data this review is compiled that can facilitate the researchers to carry out further studies and investigations on biodiversity of Tabuk region. In our study, 227 species of 157 genus were identified that belongs to 45 families of angiosperms. On comparing the above data with the endangered list of Floa of KSA (2022), we recorded 12 endangered species of plants from Tabuk region, namely, Allium sinaiticum, Astragalus collenettiae, Cerastium dichotomum, Cymbolaena griffithii, Glaucium arabicum, Leopoldia tenuiflorum, Minuartia picta, Salsola lachnantha, Salvia palaestina, Tulipa biflora, Valerianella szovitsiana, and Veronica beccabunga.. The biodiversity plays a very significant role in energy production, energy flow, pollutants removal, and biogeochemical cycling of nutrients between aquatic and terrestrial ecosystems, and for a comfortable human life existence. In the interest of protection of the wild flora and fauna from poaching and illegal trades, the Government of Saudi Arabia established several laws and regulations. Moreover, there are reports of human–wildlife conflict that need to be addressed by the Tabuk authority for the conservation of the wildlife. Public awareness, education and law enforcement could be the effective practices that should be adopted and promoted. There are many plant species reported from Tabuk region that are well known for their exceptional medicinal and traditional uses, and are considered as an important natural resources for pharmaceutical products. These plants are widely distributed in Saudi Arabia in general and Tabuk in particular, and need more investigation. Further, in Tabuk, despite rich floristic diversity, there are reports of woodcutting activities and mega developmental projects like NEOM, LINE, Red Sea Development Company, and AMALA etc. The ongoing projects requires a more comprehensive baseline data of the biodiversity of Tabuk region for a long-term sustainability.