الفهرس 
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Abstract
The present thesis aimed to describe the ecological features of the international coastal Road-West Alexandria, Egypt and to find out the relationships between the vegetation types and their surrounding environmental factors. It aims at the following objectives:
5. Study the floristic features including: record of species, life-span, life-form spectra and floristic categories of the weeds in the study area to detect the phytogeographical significance of its floristic components.
6. Quantitative analysis of the vegetation structure of plant communities in the study area in terms of spatial variations in abundance using multivariate analysis (classification and ordination).
7. Analysis of variations in the environmental factors (edaphic) to determine the soil factors controlling the abundance and distribution of the recognized plant communities in the study area.
8. Evaluation of the economic potentialities of selected plant species,
(Achellia santolina, Atriplex halimus, Atriplex semibaccata, Cynanchum acutum, Emex spinose, Halocnemum strobilaceum, Lycium shawii Roem, Pancratium maritimum, Reichardia tingitana and Suaeda pruinosa.), growing naturally along the study area. These might be achieved by investigating:
A- Phytochemical characteristics
B- Antioxidant activity
C- Antimicrobial activity
The area chosen for the present study is located in the coastal desert, lies between 29° 66’ - 28° 90’ Easting longitude (El-Ajami) and 31° 3’ - 30° 85’ Northern latitude (Ras El-Hekma).
The total number of the recorded plant species surveyed in the present study is 84 species belonging to 74 genera and related to 25 families. Family Asteraceae comprises 18 species (21.42%) of the total recorded plant species, Poaceae (12 species), Fabaceae (8 species) and Chenopodiaceae (7 species). These 4 families are represented collectively by 45 species (53.57% of the total species), while the other 9 families shared 32.15% of the species and 12 families were monospecific. These recorded species include 44 annual species (52.38%), two biennial species (2.38%) and 38 perennial species (45.24%).
According to the life-form spectra, the recorded species are mainly therophytes (54.65%) followed by chamaephytes (16.28%) then hemicryptophytes (12.79%) and geophytes, nanophanerophytes (5.81%, each). The lowest value of life-forms is recorded as helophytes which attained a value of 4.65%.
The chorological analysis of the floristic data reveals that 49 species (58.32 %) of the total number of recorded species are Mediterranean taxa. These taxa either Pluriregional (18 species =21.42%), Biregional (17 species =20.23%) or Monoregional (14 species = 16.67 %). The other floristic categories are constituted 18 species (14.52%) of the recorded species consisting of Saharo-Sindian (14.29), Saharo-Sindian + Irano-Turanian (5.95), Cosmopolitan (10.71%), Palaeotropical (2.38%) and Neotropical (1.19%).
Vegetation analysis of the study area was classified by using the multivariate techniques (classification and ordination). The classification technique applied here was the Two Way Indicator Species Analysis (TWINSPAN), while the ordination technique applied Detrended Correspondence Analysis (DECORANA). The vegetation analysis of the study area habitats, led to the recognition of four vegetation groups.
group A: comprises 8 stands dominated by Carthamus tenuis with the highest mean importance value (IV = 15.26), the abundant species include Urtica urens (IV=14.31), Urospermum picroides (IV=12.06) and Cynodon dactylon (IV = 11.25). The indicator species in this group representing low IV are Brassica tournefortii (IV= 4.53) and Chenopodium murale having a low IV of 0.36 (Table 1). Soil in these stands showed that it has the highest values for many measured soil variables (sand, pH, SO4-- and cations). Vegetation group B: Twelve stands of the studied area dominated by Lactuca serriola (IV =22.75). The abundant ones include Onobrychis crista-galli (IV=21.41), Paranochia argentea (IV = 20.91), Medicago polymorpha (IV = 17.34) and Astragalus spinosia (IV = 17.31). The indicator species in this group are Bromus diandrus (IV = 13.41) and Centaurea aegyptiaca having a low IV of 0.66. The soil of this group was characterized by high content of CaCO3, cations and high percentage of silt and porosity. group C is dominated by Bromus diandrus (IV = 20.44) inhibiting 17 stands. The abundant species include Mesembryanthemum nodiflorum (IV = 13.89), Melilotus indicus (IV = 10.39), Atractylis carduus (IV = 10.20) and Atriplex halimus (IV = 9.64). The indicator species in this group is Avena fatua (IV=6.17) (Table 1). Most of the examined soil variables in this group (pH, EC, anions and cations) attained their highest levels in the stands of this group. Floristic group D consists of 23 stands dominated by Suaeda pruinosa (IV = 10.70). The abundant species in this group include Cynodon dactylon (IV = 8.79), Phragmites australis (IV = 8.14) and Fagonia arabica (IV = 8.01). In this group, the indicator species is Tamarix nilotica (IV = 5.15) (Table 1). Soils of the stands of this group were rich in silt, clay, WHC, OC, Cl- and HCO3-.
The relationship between vegetation and soil variables is indicated on the ordination diagram produced by Canonical Correspondence Analysis (CCA) of the biplot of species-soil factors. The most important soil variables estimated in the study area are of water-holding capacity, clay, pH, available nitrogen, electrical conductivity, SAR, PAR and sodium as well as magnesium and available phosphorus being the most effective soil factors showed high significant correlations with the first and second axes of CCA ordination diagram.
The economic potentialities of ten species (Achellia santolina, Atriplex halimus, Atriplex semibaccata, Cynanchum acutum, Emex spinose, Halocnemum strobilaceum, Lycium shawii Roem, Pancratium maritimum, Reichardia tingitana and Suaeda pruinosa) which are growing naturally in the study area have been studied. Moisture content, dry matter, total ash content, crude lipid content, crude fiber content, total nitrogen content, crude protein, total soluble sugar, glucose, sucrose and total carbohydrates content have been estimated in four studied plants. On the other hand, the elementary analysis (macro and microelements) were carried out also in all the investigated plants. Quantitative determination of the secondary chemical constituents (tannins, saponins, flavonoids, alkaloids and phenolics) have been determined.
The DPPH free radical scavenging activity of the studied plant extract were estimated also. Atripex halimus showed the highest antioxidant activity with IC50 value of (0.161 mg/ml), while the lowest antioxidant activity was obtained from Halocnemum strobilaceum with IC50 value (1.351 mg/ml).
It has extract been observed that, all studied plant species extracts show different inhibition zone against same selected bacterial strains, On the other hand, all the studied plant species are also showed different inhibition zons against fungal strains.