Characterization of the wild plants in Wadi Degla Protectorate, North Eastern Desert, Egypt

The present study aimed to evaluate the floristic characteristics of the wild plants in Wadi Degla Protectorate, including taxonomic diversity, life and sex forms, dispersal types, economic potential, threats, and national and global floristic distributions. Field visits were conducted during January and April (2021), and the study area was divided to 185 locations to comprise all the Wadi. From each location, plant and seed specimens were collected. In the present study, 161 plants belonged to 128 genera, and 43 families were recorded. They inhabited three habitats (upstream, midstream, and downstream). Therophytes were the most represented life form. Bisexuals were the most represented sex form. Sarcochores were the most represented dispersal type, followed by desmochores. For small geographic range — national habitat — non-abundant plants were the most represented rarity form. For national scales, the Mediterranean and Sinai regions were the richest wild plants. For global scales, the Saharo-Sindian and Mediterranean regions were the most represented elements. Medicinal plants were the most represented good, while solid wastes were the most represented threat.


Introduction
Egypt has an area of approximately one million km 2 that divided into four geographical regions: (1) River Nile which includes the Nile Delta, Nile Valley, and Nile Faiyum, (2) Western Desert, (3) Eastern Desert, and (4) Sinai Peninsula (Zahran et al., 2009). The desert vegetation in Egypt is the most significant and distinctive type of natural plant life. The Egyptian deserts are characterized by arid and/or extreme arid climate. Perennial plants are the most dominant framework of the desert vegetation, and they are considered as indicators of the habitat conditions (Zahran et al., 2009). Wadi Degla Protectorate is located between latitudes 29° 51′ 51″ N to 30° 00′ 34″ N and longitudes 31° 16′ 03″ E to 31° 39′ 11 E, and its length reached to 30 km. It passes through the limestone rocks of the Eastern Desert, and the height of these rocks reached to 50 m along the wadi (Megahed & El Bastawesy, 1 3 Vol:. (1234567890) 2020). The area of the wadi is about 200 km 2 and is occupied by Al-Kattameya-Al-Sukhnah Road and numerous urban areas in Al-Maadi area (Megahed & El Bastawesy, 2020). The mean annual rainfall reached to 23 mm in the winter according to the Egyptian Metrological Authority (EMA, 2019). The wadi has a significant gradient, dropping c. 10 m km -1 along the course of the stream and draining from Gabal (Mountain) Abu Shama, at 578 m a.s.l. and debouching into the Nile Valley, at 21 m a.s.l. The study sites of the wadi differ in elevations, with the downstream section ranging from 85 to 200 m a.s.l., midstream from 220 to 330 m a.s.l., upstream from 340 to 420 m a.s.l., and the (downstream) tributaries from 140 to 250 m a.s.l. The main wadi is generally wide, though differs in its width among the four locations between 50 to 600 m (Hegazy et al., 2012). Wadi Digla (North Eastern Desert) was declared a protected area in 1999. It is characterized by Digla Canyon structure. The wadi is located east of Maadi district, belonging to the limestone desert wadis. It extends along 30 km from east to west. The channel receives some of the main tributaries which in turn receive runoff drainage from branched runnel. Wadi Digla is a limestone desert which comprises massive Eocene age conveniently, classified into upper Eocene and middle Eocene. The middle Eocene series includes various limestone which is the main quarrying beds for building stones and for cement industry (Hassan, 2002). According to Hassan (2002), the wide plateau of the wadi owes its origin to hard band of siliceous limestone which extends to the feet of the higher hills. The erosion affects the successive steps of the waterfall-like cliffs at different rates being the greatest at the top step and least at foot step; the result of this differential rate of action causes the whole form becomes stepped course of a runnel. The floor is partly covered by blocks which are boulders of dolomite limestone. Fossil of Nummulites sp. and Gastropoda sp. in the middle Eocene and Ostrea sp. in the Upper limestone is found. Xerophytic vegetation sustains the human population with essential goods and services (Abd El-Wahab, 2016). Also, there are some threats to the ecosystem species and habitats. These threats are caused by human and the climate aridity. Human misuse and environmental changes are serious causes of decline of global biodiversity, and now it become a serious environmental problem (Ayyad, 2003). Example of human destructive activities is the mortality of Acacia trees that used in charcoal production eastern desert of Egypt (Andersen & Krzywinski, 2007). Another examples are the overgrazing, over-cutting, arid conditions, and limited surface water availability in Sinai (Abd El-Wahab, 2016;Shrestha et al., 2003). The present paper aims at (1) preparing a list of the wild plants in the Wadi Degla protected area and (2) putting a checklist analysis in terms of taxonomic diversity, geographical distribution, life forms, flowering times, sex forms, dispersal types, rarity forms, goods and services, threats, and physical defense against different kinds of misuse (e.g., species with hairy leaves or stems, species with modified tissues used in protection, species with defensive organs, species with unfavorable taste or odor latex).

Materials and methods
One hundred eighty-five stands (each of = 10 × 10 m) were selected to represent the prevailing physiographic and physiognomic variations in Wadi Degla protected area (Plate 1). The stands covered three parts for the wadi, namely, downstream (stand no. 1-36), midstream (stand no. 37-129), and upstream (stand no. 130-185). The sampling process was carried out during January and April 2021. From each location, specimens of plant taxa were collected from each habitat, and some notifications were taken into account, such as size structure, life form, flowering time, and dispersal type of diaspores. The available information and data such as main habitats, coordinates, uses, and threats based on were recorded through the trip. The missing information were recorded according these references. (Boulos, 1999(Boulos, , 2005(Boulos, , 2009El-Gamal et al., 2008;Hassan, 2002;Hegazy et al., 2012;Tackholm & Boulos, 1974;Turki, 1993;Zohary, 1966Zohary, , 1972. The websites that used to collect more information about the recorded plants are indicated in Table 1. The list of families was arranged alphabetically according to APG IV (the Angiosperm Phylogeny Group) system (Group et al., 2016). Identification of plant specimens was carried out depending on the previous mentioned literature. Some identification was revised in the Herbarium of Faculty of Science, Menoufia University of based standard; Herbarium of Faculty of Science, Tanta University (TANE); and Herbarium of Faculty of Science, Ibb University, Yemen. Life forms of the recorded taxa were assessed using the system of Raunkiaer (1937), phanerophytes (permanent buds born at height > 25 cm), chamaephytes (permanent buds born above the soil surface till a height < 25 cm), hemicryptophytes (permanent buds born close to the soil surface), cryptophytes (permanent buds born under the soil surface in case of geophytes, in the mud overlain by water in case of helophytes, or in the water in case of hydrophytes), therophytes (the plants finish their life cycle in the form of seeds during a period less than one year), and parasites, and dispersal type was assessed using the system of Dansereau and Lems (1957). The goods and services of the recorded species was evaluated based on the field observations and reference consultation (Afefe, 2020;Bedair et al., 2020;Bidak et al., 2015;Heneidy & Bidak, 2004;Seif El-Nasr & Bidak, 2005;Shaltout & Ahmed, 2012;Shaltout & Bedair, 2022;Shaltout et al., 2010).
The abundance categories of the recorded species (very rare, rare, common, and very common) were determined based on the magnitude term of Täckholm (1974).The global distribution (i.e., floristic regions) was assessed according to the system of Good (1974) who divided the globe into six kingdoms, three subkingdoms, and thirty nine floristic regions. The theoretical framework of Rabinowitz and Synge (1981) was applied in the different types of rarity forms depending on the phytogeographical range, habitat specificity, and local abundance: large geography, wide habitat, and abundant species (LWA); large geography, wide habitats, and non-abundant species (LWN); large geography, narrow habitats, and abundant species (LNA); large geography, narrow habitats, and non-abundant species (LNN); small geography, wide habitats, and abundant species (SWA); small geography, wide habitats, and non-abundant species (SWN); small geography, narrow habitats, and abundant species (SNA); and small geography, narrow habitats, and non-abundant species (SNN). Threats are the root causes of ecosystem depletion and species extinction. In the study area, nine types of threats were identified during field trips according to the author's observations and from Seif El-Nasr and Bidak (2005) and Ahmed et al. (2014): (1) solid wastes (SW), (2) habitat loss (HL), (3) over-collecting and over-cutting (OC), (4) urbanization and tourism (UT), (5) climatic changes and environmental conditions (CE), (6) mining and quarrying (MQ), (7) disturbance by cars or trampling (DT), (8) browsing and overgrazing (BO), and (9) clearance for agriculture (CA).

Flowering time, sex, and rarity forms
There is a gradual increase in the frequency of the flowered species from January (14 = 8.7% of the total species) till reaching a maximum in March (62 = 38.5%) and April (63 = 39.1%) and then decreased again reaching a minimum in December (3 = 1.9%) (Fig. 5).

Physical defense
Eighty species have some sort of physical defense (49.7% of the total species). These species were sorted into 5 groups according to their mode of defense.  (Fig. 10).

Discussion
The number of vascular plant species recorded in the present study is 161, related to 128 genera and 43 family. Asteraceae (22 species), Poaceae (21 species), and Chenopodiaceae (20 species) comprise 39.1% of the total number of the recorded species. This finding agreed with Boulos (2005) who mentioned that the highest represented families in the Egyptian flora are Asteraceae, followed by Poaceae and then Chenopodiaceae, which  (Tadros, 1936) to 88 species (El-Adawy, 2011). On the national scale, the flora of Egypt as indicated by Boulos (2005) comprises 2145 species, related to 755 genera and 129 families. This means that the flora of the Wadi Degla contributes 7.5% of the total species, 17% of the total genera, and 33.3% of the total families. Therophytes (68 species) are the most frequent life form, followed by chamaephytes (44 species The dominance of therophytes over the other life forms seems to be a response to the hot-dry climate, topographic variation, and biotic influence (Heneidy & Bidak, 2001). The short life cycles of field weeds, the adverse climatic conditions, moisture deficiency, and substrate instability probably led to the frequent occurrence of therophytes during the favorable season (Ayyad, 1983).
In angiosperms, sex form is considered a quantitative character which can be measured on a continuous scale between strictly male and strictly female extremes (Ahmed, 2009). In the present study, the dioecious species (4.4%) were as low as the monoecious (3.1%), but both are much rare than hermaphrodites (90.7%). Ahmed et al. (2020) found that the percentage of dioecious angiosperm species had been reported to be low. Queenborough et al. (2009) reported that the low number of dioecious species may be due to that these species suffer a reproductive handicap because populations of dioecious species contain fewer seed-producing individuals. The preponderance of the hermaphroditic species (i.e., bisexual species) is a common character in the world floras; e.g., 92% of the British flora are hermaphrodites (Bedair et al., 2020).
The ecological and evolution importance of bisexuality was emphasized by Bedair et al. (2020) who suggested that the coevolution of hermaphroditic flowers in addition to animal pollination might be an important improvement by early angiosperms since pollen-producing and pollen-receiving organs present in the same flower allowed for efficient simultaneous deposition and removal of pollen. Ahmed (2009) have proposed that bisexual flowers sometimes represent the optimal use of energetic resources available for reproduction, since the fixed costs associated with male and female functions would be shared. Croteau (2010) reported that passive dispersal aids plants in the dispersion and reproduction and use dispersal units called disseminules. Many disseminules were adapted for movement by some specific dispersal agents found in the environment, such as wind and water, and animal has the ability of active dispersal, or species may have a motile larval stage, which include seeds, spores, and fruits. In the present study, the predominance of the sarcochores (soft and fleshy diaspores) indicated that the principal mode of dissemination was the sarcochory (zoochory). The wide distribution of ballochoric species (diaspore forcibly ejected from parent plant) may be due to the explosive nature of their fruits, which is often related to rapid desiccation and hence efficient local seed dispersal (Bedair et al., 2020). The commonness of pogonochoric (diaspore has long hairs), microsclerochoric (diaspores of very light weight), and pterochoric species (diaspore with scarious wing like appendages) and rarity of barochoric (very heavy diaspores), cyclochoric (voluminous diaspores), and desmochoric species (diaspores adhere to rough surfaces) reflect the suitability for wind dispersal in Egypt. In the present study, Ipomoea cairica that grows along the banks of the water bodies, only auxochoric species with no disarticulating from parent plant before diaspore is deposited at a site of further development (Bedair et al., 2020).
In general, the period from March to May (i.e., spring season) was characterized by the highest number of flowered trees and shrubs, while the period from August to January had the lowest number. In Egypt, the highest humid period of the year extended from November to April which was associated with low temperatures and evaporation, therefore, much favorable soil moisture. During this period, the plants start their growth activity reaching to the flowering and fruiting stages in March, April, and May (Bedair et al., Vol.: (0123456789) 2020). Nevertheless, phanerophytes (e.g., Calotropis procera, Ficus benjamina, and Eucalyptus camaldulensis) flower from May to August. This agrees with the study of El-Khalafy (2018) who reported that most species flowered from March to May, except phanerophytes from May to August.
There are many ways in which a species can be rare; a theoretical framework of an eight celled table is proposed by Ahmed (2009) for the different types of rarity depending on range, habitat specificity, and local abundance. In the present study, 67 plants (41.6% of the total wild species) belonged to SNN cell (small geographic, narrow habitat, and non-abundant gradient), followed by LNA (large geographic, narrow habitat, and abundant gradient 37 plants = 22.9%) and LWA (large geographic, wide habitat 29 plants = 18.1%); this is probably the most ignored category of inconspicuous and unspectacular plants, with large ranges, several habitats, but of consistently low populations. Taxa that belonged to SNA (small geographic, narrow habitat, and abundant gradient) and SNN were the classic rarities in the sense of restricted endemics, often endangered or threatened. Both internal and external factors cause plants to become rare. Internal factors refer to the plant biological characteristics, including failures in heritability, reproduction, viability, and adaptability. External factors include both natural and human factors. Natural factors refer to the ecological environment, including climate, topography, soil, and other biological factors (Chen et al., 2014). Taxa which have large ranges but are associated with particular habitats were generally quite predictable in their occurrence (LNA and LNN); these taxa tend to be precarious as a result of habitat destruction (Ahmed, 2009); this may be due to human disturbances, roads, and land use types.
The current flora mainly regarded as a mixture of the chorotypes belonging to Saharo-Sindian (81 species) followed by the Mediterranean (51 species) region. The effect of these phytogeographical zones was highly reflected in the flora of the study area. The preponderance of Saharo-Sindian chorotype could be attributed to the location of Egypt in the center of Saharo-Sindian region (Barakat et al., 2014). Other floristic elements such as Euro-Siberian, Sudano-Zambezian, Cosmopolitans, Paleotropical, Neotropical, Australian, and Pantropical were in a varying miniature representation reflecting their differential capability to penetrate the region (Shaltout et al., 2015).
At a national scales, the Mediterranean (105 plants) and Sinai regions (98 plants) have the highest number of wild plants in the study area. The Mediterranean vegetation was dominated by evergreen sclerophyllous shrubs that form maquis (over 2 m in height), garrigue and jaral (0.6-2 m), and phrygana or batha (< 0.6 m) plant communities (Bedair et al., 2020). Sinai Peninsula has rock and soil types that make existence of plants possible. In addition, the landscape is characterized by a variety of landforms (plains, wadis, springs, salt marshes, and sand dunes) (Ahmed, 2009). There was in fact a great deal of water draining down the wadis, sometimes as violent and destructive flash floods but under normal circumstances; most of the water was underground, occasionally surfacing to produce short sections of freely flowing permanent water, thus making the area rich in plants. The desert region comes in the third order (90 plants), where plants show a number of morphophysiological features that allow them to adapt with the high aridity and low nutrient availability such as deep root systems, tolerance to high radiation levels, and capacity for clonal spread and presence of thorns and spines and small leaves (Bedair et al., 2020).
One hundred fifty species in Wadi Degla (93.2% of the total species) have at least one aspect of the potential or actual goods, of which 111 taxa that had medicinal uses. For example, leaf and root decoction of Chenopodium ambrosioides is used for diuretic bladder. Edible of leaves and fruits of Capparis spinosa is used for coughs, and Urtica urens are used as an expectorant, purgative, diuretic, hemostatic, vermifuge, and for the treatment of eczema, rheumatism, hemorrhoids, hyperthyroidism, and cancer (Hassan & Abdelmohsen, 2018;Hattab et al., 2020;Kavalalı et al., 2003) Leaves of Hyoscyamus muticus are used for fever treatment, and leaf decoction of Pluchea dioscoridis is used for infantine ailments and rheumatic pains (Ayyad, 1998;Bidak et al., 2020;Hassan & Abdelmohsen, 2018). Rubbing young flowering branches of Achillea santolina reduces toothache and rheumatic pains, while the entire plant of Fumaria parviflora was recommended to keep vitality of children (Boulos, 1983;Omar et al., 2018). Leaf decoction of Anchusa hispida is diuretic and is used in the treatment of rheumatism. Leaves and flowers of Peganum harmala are used for rheumatism and stomach problems, but seeds are used as an anthelmintic and as a narcotic. Capparis spinosa is used in rheumatism, enlarged spleen, and tubercular glands (Batanouny et al., 1999;Bidak et al., 2020;Shams et al., 2017). Phragmites australis is a folk remedy for abscesses, arthritis, bronchitis, cancer, cholera, cough, diabetes, dropsy, dysuria, fever, flux, gout, hematuria, hemorrhage, hiccup, jaundice, leukemia, lung, nausea, rheumatism, sores, stomach, thirst, and typhoid (Shams et al., 2017).
Eighty nine taxa (55.3% of the total species) can be grazed and browsed by the domestic and wild animals (e.g., Melilotus indicus, Trigonella stellata, Fagonia arabica, Malva parviflora, Deverra tortuosa, and Sarcocornia fruticosa). There are some examples of selective use of different plant organs at different seasons. Small branches of Tamarix nilotica were apparently good for camels and goats, while sheep prefer its flowers only (Shaltout et al., 2010). Twenty nine taxa are subjected to cutting for fuel (8.0%) such as Lycium shawii, Sarcocornia fruticosa, Nitraria retusa, and Tamarix nilotica (Bedair et al., 2020). Al-Sodany et al. (2019) and Hassan et al. (2015) reported that the biomass of Calotropis procera was used in biofuel and bioenergy production.
The timber plants were limited allover Egypt; only 8 species suitable as timber (5.0%) such as Phoenix dactylifera, Tamarix aphylla, and Tamarix nilotica (Shaltout & Ahmed, 2012). Fruits, flowers, vegetative, and ground parts of 42 taxa (= 26.1% of the total taxa) were eaten by local inhabitants. For example, Deverra tortuosa was eaten as a salad, and dates of Phoenix dactylifera were eaten (Shaltout & Ahmed, 2012). Thirty six species (22.3% of the total species) are of several traditional uses such as an ornamental value (e.g., Chrysanthemum coronarium); others are used in tanning and detergent and in making handicrafts such as Phoenix dactylifera and Luffa aegyptiaca (Shaltout & Al-Sodany, 2002). Deverra tortuosa may be used as a natural herbicide as well as a good source for yeast control (Guetat et al., 2019). The wood of Phoenix dactylifera was used as a tooth brush (Shaltout & Ahmed, 2012). A recent study on Pluchea dioscoridis proved that the ethanolic leaf extract has antifungal activity (Metwally et al., 2022).
One hundred and thirty two species in Wadi Degla (82.0% of the total species) have at least one aspect of the environmental services. Sand controllers, such as sand accumulation and windbreaks, are the species which have been seen to deal effectively with drift sand such as Ammophila arenaria, Nitraria retusa, and Panicum turgidum; sand controllers that make efficient wind breaks (e.g., Ricinus communis and Tamarix trees) propagate themselves when once established, either by seed or by their creeping root system. Some other species are especially useful in dealing with sand in salt marsh area such as Atriplex portulacoides and Zygophyllum album (Ahmed, 2009). Sand accumulation had the maximum contribution to the flora of Wadi Degla due to the predominance of sandy soils that characterize this region (Zahran et al., 2009). Sand accumulators (such as Nitraria retusa, Ricinus communis, and Tamarix trees) play a role in preventing soil erosion, increasing soil deposition and improving drainage of low lands (Seif El-Nasr & Bidak, 2005). Sometimes, they make efficient windbreaks that propagate themselves either by seeds or by creeping root systems such as Ricinus communis and Tamarix trees (Shaltout & Ahmed, 2012).
Threats to the world's plants continue to increase as a result of human activities (IUCN, 2003(IUCN, , 2010. From the well-documented threats are solid wastes, habitat loss, poor land management, over-collection, overgrazing, and climate change. Most studies suggest that the rate at which plant species are being lost, or at least reduced in numbers, is faster than the speed at which scientists, land managers, policy makers, and others can or will respond (IUCN, 2003(IUCN, , 2010. One hundred and sixty one taxa in the present study are damaged during solid wastes. The human-induced threats, such as over-collection, overgrazing, solid wastes, mining, rock crusher machines, industrialization, air pollution, military activities, and urbanization (e.g., new settlements, infrastructure, water and petroleum pipelines, power station, digging new wells, and highways), give rise to alterations in habitat conditions with consequent alteration in vegetation structure and the destruction of macro-and micro-vegetation elements (Hussein et al., 2021;Nakahama et al., 2015).
One hundred fifty-eight species, in the study area, are exposed to habitat loss due to urbanization and tourism; clearance for agriculture and construction processes is one of the major threats which impact many species in the Egyptian flora especially in the Mediterranean region. This has not only led to the complete destruction of the habitats, but also its degradation of vast areas of habitat surrounding them. Consequently, this threatens plants in these habitats, e.g., Lycium shawii (Shaltout & Ahmed, 2012).
One hundred forty one species, in the study area, are exposed to over-collecting and over-cutting. Most wild plants species were subjected to over-collecting and over-cutting by local inhabitants, herbalists, and scientific researchers. The collection of wild native medicinal plants for commercial trade had no regulation. The most serious aspect was that it usually targets rare and localized flora leading to damage them further (Seif El-Nasr & Bidak, 2005). Ahmed et al. (2020), Heneidy (1991), and Heneidy and El-Darier (1995) recorded that the human activities in Omayed area (e.g., clearing and wood cutting of natural vegetation) are more severe effective on the vegetation than the overgrazing by livestock. There was an increasing demand by local Bedouin populations for fuel woods and targeting larger woody perennials (especially woody branches and roots). The elimination of large woody perennials (which take many years to reach mature sizes) severely reduces the structural complexity of an already highly exposed environment, rapidly accelerating soil movement and erosion, reducing water retention potential and the chances of germination of annuals and smaller plants to become established The removal of woody perennials initiates the first steps in a process of complete transformation of the natural landscape (Seif El-Nasr & Bidak, 2005). One hundred twenty nine species, in the study area, are exposed to climate that was still somewhat theoretical until 2005 and are becoming more evident, and the mitigation of its effects on much localized species represents an important challenge. Due to climate change, the wild population of species could be in extreme danger in a relatively near future.
The effects of man on desert vegetation may be direct on the vegetation cover itself or indirect through their influence on the other components of the ecosystem. Human activities affecting the plant cover directly, resulting in the deterioration of desert vegetation, include intensive collection of medicinal plants and removal of plants during the construction of roads and building of new cities (Hassan, 2002).
Some plants have defensive parts that reduce or avoid consumption by herbivores (Heneidy & Bidak, 1999). In the present study, 5 groups of physical defense were recognized in 80 taxa. The first group includes 41 plants with that have hairy leathery leaves and hairy stems; sometimes, the hairs become stiff or rough and irritating (e.g., Arenaria serpyllifolia, Chenopodium ambrosioides, and Diplotaxis harra). Grime et al. (1968) reported that epidermal hairs reduce the palatability of range species or inhibit the passage of food through the gut of animals. Díaz and Cabido (1997) reported that hairy plants may be drought-tolerant adaptations, while Perkins (2010) reported that the hairy plants could help in reflecting more sunlight, reducing detrimental heating of the plant.
The second group includes 18 plants with modified parts such as spines or spinescent branches and may be considered as grazing-resistant species (e.g., Zilla spinosa and Cenchrus pennisetiformis) or has defensive parts in the form of densely woody pointed terminates or short spine-like branches (e.g., Lycium shawii). The defensive parts of this group (mostly shrubs or sub-shrubs) are acquired as a result of herbivores attack or are already formed in the early stages of the plant life cycle (Shaltout & Ahmed, 2012). The third group includes 17 plants that have sticky latex with unpleasant taste and odor (e.g., Hyoscyamus muticus, Haplophyllum tuberculatum, and Chenopodium ambrosioides). They seem to be toxic for livestock (Shaltout & Ahmed, 2012). The fourth group includes 8 plants that are covered with scales, dots, or spots such as Deverra triradiata, Deverra tortuosa, and Sarcocornia fruticosa. A scale or peltate hair is a type of trichome that has a plate or shield-shaped cluster of cells attached directly to the surface or borne on a stalk of some kind and had a role in physical defense against insect herbivores (Cardoso, 2008). The fifth group includes 4 species that do not appear to have any form of defense, but they are weak plants that occur under woody plants or rocks and hence are out of reach by grazing animals.

Conclusion
The most dangerous activity is the quarries of building stones will increase the erosion of the geological structure of the wadi. In this study, Wadi Degla is classified according to physiographic variations: downstream, midstream, and upstream. The main dominating species are Atriplex leucoclada, Zygophyllum coccineum, and Zilla spinosa. Accidental vegetation appeared after winter rainfall in 2020. This vegetation is a part of wadi vegetation which is exposed to remove after construction of the main traffic road. The new cities, Zahra el Maadi, Digla, and Amal, were built near the downstream. The declaration of the wadi as protected area is to protect the wild life in the desert wadi after the highly human activities. Ecological principles must be observed in the consideration of the exploitation of the area, and conservation of wild plants should be a priority. Sustainable management of the floral biodiversity in Wadi Degla requires effective measures to be implemented to counter the damaging human impacts that lead to the loss of certain plant populations and hence the to the modification of complex plant communities.