On the Ecology and Phytosociology of El-Omayed Area (original) (raw)
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Structure of the Common Plant Population along Alamain-Wadi El-Natrun Desert Road
Australian Journal of …, 2009
Vegetation along Alamain-W adi-El-Natrun desert road is characterized by paucity of trees and shrubs. Aridity and severe impact of human activities, overgrazing, over cutting, severe reclamation and uprooting, are the main causes of the depletion of these important woody resources. Alamain-W adi-El-Natrun desert road extends about 133 km from Marina-Alamain (on the Mediterranean coastal region) in the north to Wadi El-Natron in the south. The phytosociological study of this road was based on the application of TW INSPAN on 162 species recorded in 50 stands, led to the recognition of 7 vegetation groups at the 4th level of classification. The application of DECORANA on the same set of data indicates a reasonable segregation among these groups along the ordination plane of axes 1 and 2. The vegetation groups are named after the first and occasionally the second dominant species (the species that have the highest percentage and/or the highest relative cover). These groups are named according to their dominant species as follows: A-Cornulaca monacantha, B-Launaea nudicaulis, C-Stipagrostis ciliata, D-Cornulaca monacantha-Artemisia monosperma, E-Thymelea, F-Lycium schawii, and G-Echiochilon fruticosum-Noaea mucronata. These groups are completely dissimilar to that recorded by previous studies on the natural habitats of the same road which may indicate that changes have been occurred in the study area after the construction of this road. Height/diameter ratio for the dominant plant communities was less than unity, which means that the diameters of these species exceed their heights and hence, their individuals tend to expand horizontally rather than vertically. The size and age of the studied plant life forms were negatively skewed correlated, which favors the establishment of seedlings of some species and controls the abundance of species in sand dunes.
Vegetation analysis of some desert rangelands in United Arab Emirates
2008
The present study deals with the vegetation analysis of some desert rangelands in United Arab Emirates (UAE). 615 stands were selected to represent the variations in 3 major types of habitat in 7 locations in this country. In each stand the present species were recorded and their cover was estimated by line-intercept method (m/100m) and a composite soil sample was collected. 97 species belong to 91 genera and 29 families were recorded. The application of TWINSPAN classification technique on the cover estimates of the 97 species recorded in 615 stands led to the recognition of ten vegetation groups at the level six of classification; These groups are named after the first two dominant species as follows: Prosopis cineraria -Cyperus conglomerates, Acacia tortilis ssp. tortilis -Arnebia hispidissima, Cornulaca monacantha -Haloxylon salicornicum, Acacia tortilis ssp. tortilis -Tephrosia purpurea, Acacia tortilis ssp. tortilis -Euphorbia larica, Haloxylon salicornicum -Acacia tortilis ssp. tortilis, Cornulaca monacantha -Arthrocnemum macrostachyum, Calotropis procera -Acacia tortilis ssp. tortilis, Tribulus terrestris -Rhazya stricta and Acacia tortilis ssp. tortilis -Dipterygium glaucum. Result of ordination using DECORANA indicates a reasonable segregation among these groups along the ordination axis 1 and 2. The communities characterized by Acacia tortilis ssp. tortilis represent the climax stage of the vegetation in the study area. The effects of environmental factors and human impacts on species diversity and abundance of these communities were assessed.
Plant communities and their environmental drivers on an arid mountain, Gebel Elba, Egypt
Vegetation Classification and Survey, 2020
Aims: Gebel Elba is an arid mountain range supporting biological diversity that is incomparable to any other region of Egypt. This mountain has a vegetation structure and floristic community similar to the highlands of East Africa and the southwestern Arabian Peninsula. We aimed to provide the first classification of the vegetation units on Gebel Elba and identify the environmental factors controlling their distribution. Study area: Wadi Yahmib and its tributaries, which drain the northwestern slopes of Gebel Elba, southeastern Egypt. Methods: On the basis of 169 relevés, we used TWINSPAN to classify the perennial vegetation. We calculated separate GAMs for the deciduous and evergreen species to describe the patterns for each leaf strategy type with elevation. We used CCA to quantify the relationship between the perennial vegetation and the studied environmental factors. To estimate diversity and our sampling strategy, we used rarefaction curves for species richness. Results: We identified seven communities along the elevational gradient of Wadi Yahmib and its tributaries. We found that each community was restricted to a confined habitat depending on its drought resistance ability. Deciduous Vachellia woodland was the main vegetation type on Gebel Elba, while evergreen Olea woodland appeared in small fragments at higher elevations. We analysed the distribution patterns of deciduous and evergreen trees along the elevational gradient. We found a turnover at 500 m, indicating a potential ecotone between the Vachellia and Olea woodlands that was occupied by a Ficus community. CCA revealed the importance of altitude and soil quality in determining the vegetation structure of Gebel Elba. The species richness increased with elevation as a result of reduced stress and increased water availability at the upper wadis. Conclusions: This study identified seven vegetation units in the study area and showed the importance of orographic precipitation, soil quality and the complex topography in determining the habitats. Taxonomic reference: Boulos (2009); names updated according to POWO (2019).
Notulae Scientia Biologicae, 2014
For two successive years, the floristic diversity and vegetation composition in the southern part of the Eastern Desert of Egypt were investigated through four transects (3 crossing the Eastern Desert and one along the Red Sea). The data collected from 142 stands covering the study area included the species composition, functional groups, chorology and occurrences (Qvalues). A total of 94 plant species belonging to 33 different families were recorded, with Asteracea, Zygophyllaceae, Fabaceae, Poaceae, Chenopodiaceae and Brassicaceae as the largest families. Shrubs represented the largest functional group (39.4%), while perennial herbs represented the smallest ones (12.8%). Species occurrence (Q-value) revealed that Zilla spinosa, Acacia tortilis subsp. raddiana, Morettia philaeana, Caroxylon imbricatum, Zygophyllum coccineum and Citrullus colocynthis had wide ecological range of distribution (dominant species, Q-values ≥ 0.2). Saharo-Arabian chorotype was highly represented (72.6 %) in the flora of this area, eventually as mono, bi or pluriregional. Classification of the data set yielded 7 vegetation groups included: (A) Zilla spinosa-Morettia philaeana, (B1) Zilla spinosa-Citrullus colocynthis-Morettia philaeana, (B2) Zilla spinosa, (C1) Zygophyllum album-Tamarix nilotica, (C2) Zygophyllum coccineum-Tamarix nilotica, (D1) Zilla spinosa-Zygophyllum coccineum and (D2) Zilla spinosa-Acacia tortilis subsp. raddiana-Tamarix aphylla-Balanites aegyptiaca.
Vegetation of Thumamah Nature Park: a managed arid land site in Saudi Arabia
Thumamah Nature Park is located at about 100 km north of Arriyadh (Saudi Arabia), having an area of 170 km 2 . The Park was established since 30 years ago. The aim of this study is to analyze the vegetation structure in relation to the environmental factors in different habitat types. The phenological activities around the year of the 20 dominant species were monitored. 119 species were identified, of which 51 (43 %) annuals and 68 (57 %) perennials after 30 years of exclusive human impact. The Saharo-Arabian component species were the highest among the monoregional species (64 %) in most life forms, while the Sahelien-Somali Masai attained the highest among the biregionals (46 %). The TWINSPAN, DCA and CCA analyses separated seven vegetation groups. The first two groups were dominated by psammophytic species, which occupy the lower sandy plain as shown in group I with Rhanterium epapposum-Rhazya stricta and group II with Pennisetum divisum-Haloxylon salicornicum. The escarpment habitat was characterized by three groups, viz., group III with Acacia gerrardii-Panicum turgidum, group IV with Panicum turgidum and group V with Acacia ehrenbergiana-Lasiurus scindicus. Vegetation in the upland plateau was represented by the remaining two groups; group VI with Helianthemum lippii and group VII with Helianthemum kahiricum. The environmental variables that affect the species distribution and diversity in the park include the altitude, soil texture, pH, EC, Ca, Mg and Mn. The increased plant species richness, turnover, evenness and cover were mostly due to the increase of the herbaceous species. Plant populations showed interspecific variations in their relative timing of phenological phases with reproductive activity period ranged between 3 and 6 months with unimodal flowering peak. Three floweringfruiting activities were recorded during late winter-spring, summer and late autumn-early winter. In an attempt to explain the vegetation dynamics after 30 years conservation, the progressive succession varied among the different habitat types, including the lower sandy sites, the escarpment and the upland rocky habitats, which reflect the relationship between altitude, edaphic factors and the type of vegetation units in each habitat type after exclusion of the human impact.
PRELIMINARY ANALYSING OF PLANT DIVERSITY OF HIGH ALTITUDE AREA OF ALBAHA REGION, SAUDI ARABIA.
The study on the floristic analysis and plant diversity was carried out during the years 2014 and 2016 covering the high altitudinal plateau between 1900 to 2475 mater above sea level (m. a. s. l.) of Al Baha region, Saudi Arabia. This attempt was made, to document the density; frequency and diversity of plant species existing in different land forms, to identify the priorities of conservation and rehabilitation for the least occurrence plant species and Juniperus procera and Acacia origena habitats in the future plan. Random quadrat methods of 25*25 m were laid out in various parts of the region to reach the total of 73 sample plots. The data was analyzed using different ecological indices and tools. The out come of the analyzed data showed a total of 187 plant species belonging to 147 genera and 67 families, in which 3 are endemic to Arabian Peninsula and one is endemic to Saudi Arabia. Hyparrhenia hirta, Achillea biebersteinii, Cynodon dactylon, Themeda triandra Juniperus procera and Eragrostis papposa have the highest density per hectare with a value of 226, 176, 167, 134, 116 and 107 respectively. Frequency of plant species showed different trend of plant arrangement in different sample plots unlike the density. For instance Juniperus procera, Acacia origena, Dodonaea viscose, Psiadia punctulata and Sageretia thea have more frequency with a value of 0.86, 0.67, 0.47, 0.45 and 0.44 respectively. The dominant vegetation structure is a woodland dominated by Juniperus procera and Acacia origena and grassland dominated by Hyparrhenia hirta and Themeda triandra. Average tree cover is 25%, shrub cover is 17% and herbaceous cover is 36% with an average of 77% vegetation cover.
Plant Distribution in Arid Ecosystems of Eastern Alborz Ranges at 36° Latitude
International Journal of Biology, 2015
Iranian natural ecosystems have aesthetic, conservation and genetics values and provide many functions and services, but have become vulnerable. This investigation aimed to (1) survey flora of an arid-steppe montain ecosystem, (2) analyze the ecological characteristics of the vegetation in relation to altitude and soil properties and (3) elaborate on ecophysiological processes. Samples of soil and plants were collected randomly in three altitudes at about 36° latitude in Parvar Protected Area (PPA), Iran. Plant species were identified, ecologic and floristic data were collected and statistical analyses were performed using Excel and SPSS. Physiognomy of the region is steppe. The type of soil is sandy-loam, and it becomes loamy with increasing altitude. Majority (45.5%) of species are cryptophytes and belong to Irano-Turani region followed by chameophytes (36.4%) and therophyte (18.1%). Artemisia aucheri, Eremopyrum elengutum and Stachys aucheri dominated at the upper (2338 m), middle (2009m) and lower (1783 m) elevations above sea level, respectively. Onobrychis cornuta and Astragalus ochrochlorous were also common to all stations. Ecological indices showed reducing trend with hike in altitude except dominance index which increased. Artemisia aucheri was the overall dominant plant and in need of ecological management. Ecophysiological interaction of plant species with environmental parameters at local level undoubtedly determines their community structure, scale and pattern of distribution. Since plant species in semi-arid regions have developed specific adaptation strategies to cope with environmental changes, it is useful to link local adaptation strategies (for example, avoidance, tolerance, resistance) and physiological processes to global changes. In this way, knowledge on morphology, physiology, life-history, phenology and behavior gained from ecological studies based on individuals, communities and ecosystems can be analyzed in ecological and evolutionary context and thus, afford the tool of predicting responses and simulating ecosystem models to environmental changes in future.
Floristic Composition and Vegetation Analysis in Suez Governorate, Egypt
The present study provides a detailed depiction of the floristic composition and vegetation analysis of four habitats in Suez Governorate, Egypt. The investigated habitats include desert, waste lands, crop fields and orchards. A total of 107 species (56 annuals, 2 biennials and 49 perennials) belonging to 93 genera and 33 families were recorded in the study area. The most represented families were Asteraceae, Poaecae, Brassicaceae, Fabaceae and Chenopodiaceae. Therophytes were the most prevailing life-forms. Chorological analysis revealed that the Saharo-Sindian and Mediterranean chorotypes either pure or extended into other regions form the major component of the floristic structure. The application of TWINSPAN classification technique on the importance values of 107 plant species recorded in 40 stands representing the studied habitats produced four vegetation groups named after their dominant species. Group A: dominated by Zygophyllum coccineum, group B: dominated by Tamarix nilotica, group C: dominated by Beta vulgaris, Chenopodium murale and Melilotus messanensis and group D: dominated by Oxalis corniculata. Species richness, Shannon-Wiener and Simpson indices measurements indicated that vegetation groups D and C were the most diverse ones, followed by groups A and B. Detrended Correspondence Analysis (DCA) results indicated a reasonable segregation among these groups along the first and second axes. Linear correlation of soil variables with the importance values of some dominant species and the application of Canonical Correspondence Analysis (CCA-biplot) indicated significant correlation between species distribution of the studied habitats and the soil variables such as, soil texture, organic matter, CaCo 3 , pH, electrical conductivity, bicarbonates, chlorides, sodium, magnesium, potassium and calcium.
Vegetation and Environment of Gebel Serbal, South Sinai, Egypt
2006
This study aimed to analyze the floristic composition and the distributional behavior of plant communities in relation to the main physiographic features and soil properties in Gebel Serbal. Canopy cover of plant species and altitude were measured in 58 stands (20 m x 20 m). Gravel percentage, soil texture, hygroscopic moisture, pH, electric conductivity, total carbonate, total nitrogen, available phosphorus, and soil organic matter were determined in each stand. The results revealed that Serbal Mountain is characterized by distinguished microhabitats and low to moderate human impact that result in unique floristic composition and vegetation patterns. One hundred and six species were identified in this study including 11 endemic species, and 36 characteristic species. Based on multivariate analyses, seven main plant communities were recognized in Gebel Serbal area. Distribution of the plant communities was more related to altitude, hygroscopic moisture, and gravel percentage rather than to sand, silt and clay fractions, soil organic matter, and total nitrogen. The present study indicates that Gebel Serbal is the most diverse area in South Sinai, and has a high conservation value. We recommend that Gebel Serbal, a part of St. Katherine Protectorate, should be declared as habitat/species management area. Tree species Acacia tortilis (Forssk.) Hayne subsp. raddiana (Savi) Brenan; 1,2,6 Colutea istria Mill.; 3,4 Pistacia khinjuk Stocks v. glaberrima; 4,5 Shrub species Anabasis articulata (Forssk.) Moq.; 2,3,6 Atraphaxis spinosa L.; 1,2,4 Cotoneaster orbicularis Schltdl; 1,3,4 Crateagus x sinaica Boiss.; 3,4 Deverra triradiata Hochst. ex Boiss.; 4 Ephedra alata Decne.; 3,4 Ficus palmata Forssk.; 2,3,4 Globularia arabica Jaub. & Spach; 1,3,4,5 Retama raetam (Forssk.) Webb & Berthel; 1,2,6 Sub-shrub species Anarrhinum pubescence Fresen.; 2,4,5,6 Artemisia herba-alba Asso.; 2,4,5 Artemisia judaica L.; 1,6 Buffonia multiceps Decne.; 3,4 Fagonia mollis Delile.; 1,2,6 Heliotropium arbainense Fresen.; 1,2,3,4,5 Kickxia macilenta (Decne.) Danin; 2,3,4,5 Polygala sinaica Botsch.; 3,4,5,6 Pulicaria crispa (Forssk.) Oliv.; 2,4 Stachys aegyptiaca Pers.; 2,4,5 Varthemia montana (Vahl) Boiss.; 4,5 Perennial herb species Ballota undulate (Fresen.) Benth.; 2,4,5 Echinops spinosissimus Turra; 3,4,5 Galium sinaicum (Delile ex Decne.) Boiss.; 1,4,7 Juncus rigidus Desf.; 1,2,4 Mentha longifolia (L.) Huds.; 2,4,5 Origanum syriacum L.subsp. sinaicum (Boiss.) Greuter & Burdet ; 2,3,4 Phlomis aurea Decne.; 3,4 Poa sinaica Steud.; 2,4 Polypogon viridis (Gouan) Breistr.; 2,3,4 Silene leucophylla Boiss.; 1,3,4 Silene linearis Decne.; 3,4 Tanacetum santolinoides (DC.) Feinbrun & Fertig ; 3,4 Verbascum sinaiticum Benth.; 2,4,5