الفهرس 
ACKNOWLEDGEMENTSOnly 14 pages are availabe for public view
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Abstract
The present study provides a detailed description of the floristic features, ecological features, and economic potentialities of six Cyperus species in canal banks and drain canals, sand formations, salt marshes and River Nile bank in the Nile Delta of Egypt was investigated and it aims at the following objectives: /1-Study the floristic features including: record of plant species, distribution pattern, life-span, life- form spectra and chorological affinities of the wild plants associated with the selected Cyperus species in the study area to detect the taxonomic and phytogeographical significance of its floristic components. 2-Quantitative analysis of vegetation structure of plant communities associated with the selected Cyperus species in the study area in terms of spatial variations in abundance using multivariate analysis (classification and ordination). 3-Analysis of variations in the environmental factors (edaphic) to determine the soil factors controlling the abundance and distribution of the recognized plant communities associated with the Cyperus species in the study area. 4-Evaluation of the economic potentialities of some selected Cyperus species through: Phytochemical analysis, nutritive value, elementary analysis, antioxidant activity, antibacterial potentiality and antifungal potentiality. The area chosen for the present study is located in the northern part of Nile Delta region of Egypt which cover the north and middle borders of five Governorates of the Nile Delta region of Egypt, namely: Damietta, El-Dakahila, Kafr El-Sheikh, EL-Qalubilya and Giza.The total number of surveyed plant species was 111 plant species, categorized into 48 annuals, 61 perennials and two biennials, and classified under 93 genera and 30 families. The life –form spectra of the recorded species comprised 51 therophytes, 29 cryptophytes, 15 hemicryptophytes, nine chamaephytes and eight phanerophytes. chronologically, the Saharo-Sindian element was the most represented element (36 species), followed by Irano-Turanian (20 species) and Euro-Siberian (11 species). While, Cosmopolitan element was represented by 11 species, Pantropical by16 species, Palaeotropical by seven species, Neotropical by four species and two species for both cultivated and naturalized elements. The vegetation analysis of plant communities associated with the chosen species in the study area was classified by using multivariate techniques (classification and ordination). Classification technique applied here was Tow way indicator species analysis (TWINSPAN), while the ordination technique applied was Detrended Correspondence analysis.These classification of the 39 sampled stands led to the recognition of five groups (A-E). The characteristics dominant and codominant species of vegetation groups were Stipagrostis lanata, Echinops spinosus and Moltkiopsis ciliata (A), Ludwigia stolonifera and Eichhornia crassipes (B), Cyperus articultus and Malva parviflora (C), Arthrocnemum macrostachyum and Cyperus laevigatus (D), and Solanum nigrum, Persicaria salicifolia, Saccharum spontaneum, Convolvulus arvensis and Sonchus oleraceus (E). Detrended Correspondence Analysis (DCA) ,Correspondence Analysis (CCA).exhibited that sulphates, calcium, potassium, magnesium, cobalt, cadmium and calcium carbonates were the highest influential soil variables monitoring the richness of the recognized groups. The correlation between edaphic factors and ordination axes led to the definition of the most active soil gradients which correlate with the distribution and abundance of vegetation groups in the of the Nile Delta region of Egypt. The electrical conductivity, sodium, potassium, magnesium and calcium cations, clay, prosity, potassium , chlorides and bicarbonates were the most effective soil variables which have high significant correlations with the first and second axes.The economic potentialities of the six selective species in family Cyperaceae which are growing naturally in the study area have been studied. Water content, crude lipids, total ash content, crude fibers, total nitrogen, crude proteins and total carbohydrates have been estimated in the six studied plants. On the other hand, the elementary analysis ( macro and microelements) were also determined in all investigated plants. The quantitative determination of secondary chemical constituents (tannins, saponins, flavonoids, alkaloids and phenolics) were also determined. The antioxidant activity by using DPPH free radical scavenging activity for an assay of the radical scavenging activity of plant extracts. The extract of Cyperus laevigatus showed the highest antioxidant activity while the weakest activity obtained from the extract of Cyperus articulatus. from the phytochemical analysis of secondary metabolities and the antioxidant activity using DPPH free radical scavenging activity of the studied plant extracts, it can be concluded that Cyperus laevigatus could be considered as a potential source of natural antioxidant as well as a safe alternative agent to synthetic antioxidants.The antibacterial Erwinina carotovora, Enterobacter cloacae and Escherichia coli were Gram negative bacteria and strains were gram positive bacteria as Bacillus subtilis, Strepto pyogenins and Staph aweus and the antifungal using Candida albicans species assay were carried out on these plants and insured their antimicrobial activity.