Plant communities and their environmental drivers on an arid mountain, Gebel Elba, Egypt (original) (raw)
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Elevation-richness pattern of vascular plants in wadis of the arid mountain Gebel Elba, Egypt
Mountains provide a unique opportunity to study drivers of species richness across relatively short elevation gradients. However, few studies have reported elevational patterns for arid mountains. We studied elevation-richness pattern along an elevational gradient at the arid mountain Gebel Elba, south-east of Egypt, expecting a unimodal richness pattern. We sampled 133 vegetation plots (10 × 10 m) in four wadis along an elevational gradient from 130 to 680 m which represents the transition from desert to mountain wadi systems. We used generalised additive models to describe the relationship between elevation and plant species richness. We found a strong increase in species richness and Shannon diversity at low elevations followed by a plateau at mid-to high elevations. When we analysed each tributary as a single gradient, no pattern was found. The analysed elevational gradient seems to be a major stress gradient in terms of temperature and water availability, exhibiting a trend of increasing species richness that changes to a plateau pattern; a pattern rarely observed for wadi systems in arid mountains. We discuss the observed pattern with the climatic stress hypothesis and the environmental heterogeneity hypothesis as possible explanations for the pattern.
PLANT DIVERSITY, VEGETATION CONDITIONS AND LANDFORMS OF GEBEL SERBAL, SOUTH SINAI, EGYPT
This study aims to evaluate plant diversity and the distributional behavior of plant communities of Gebel Serbal in relation to the main physiographic features and soil properties. Species richness, taxonomic diversity and endemism of South Sinai in general and characteristic mountains including G. Serbal, G. Catherine, and G. Musa in particular were evaluated. Beta diversity was also measured using β T to represent the biotic change between different landforms in G.Serbal area. The results revealed that G. Serbalisthe most diverse mountain in plant diversity as compared with other mountains in the area or South Sinai as a whole. Gebel Serbal supports about 164 plant species of which 145 plant species are identified in the present survey including 11 endemic species. About 60% of the identified species have conservation value as rare, vulnerable, endangered or extremely endangered species. Beta diversity (β T ) between landforms of G. Serbal along a moisture gradient shows high values of biotic turnover between terraces and wadis (0.735), gorges and wadis (0.730), and between slopes and wadis (0.691), which may reflect rapid ecologically significant changes in the wadis environment. On the other hand, lower values of β T are measured between slopes and terraces, and between gorges and slopes. TWINSPAN and CANOCO multivariate analyses indicate the importance of moisture gradient in distribution of the plant communities of G. Serbal. Finally, the study recommends appropriate management of plant diversity, threatened plant species and endemics in G.Serbal mountainous habitats in general.
International Journal on Environmental Sciences, 2018
The present study provided an investigation of the floristic analysis, vegetation composition and species distribution along 100 m intervals of the elevation gradient (2000 m a.s.l.) on Jabal Musa (south Sinai, Egypt), and assessed the role of elevation and other soil parameters controlling plant diversity. It is a study on altitudinal variation in vegetation in a very dry climate. The vegetation structure, growth forms, and species diversity were analyzed within the 7 elevation belts on Jabal Musa area, 44 sample plots, 81 species (including one bryophyte), and 17 examined environmental factors including altitude. Asteraceae, Lamiaceae, Zygophyllaceae and Brassicaceae contributed about 41% of the species, represented in all belts. Based on the Bray-Curtis dissimilarity coefficients, it exhibited floristically homogeneous higher belts than the lower belts. Along moisture gradient, the Non Metric Multidimensional Scaling (NMDS) ordination was able to distinguish the different vegetat...
The present study aims to investigate the variation in vegetation and species diversity in three inland wadis (Wadi Solaf, W. Romana and W. El- Akhdar) which drain their water from surrounding high mountains to the main channel of Wadi Feiran in South Sinai. It attempted to compare the floristic diversity between these wadis to recognize the different distribution patterns of species, and to assess the role of the edaphic factors which control the distribution of the plant communities. Forty-five sample plots were selected to represent as much as possible the variation in the vegetation, and georeferenced using GPS techniques. A total of 116 species (45 annuals and 71 perennials) belonging to 95 genera and 37 families were recorded, with Asteraceae, Brassicaceae, Fabaceae, and Zygophyllaceae represented the species-rich families. Therophytes constituted the main bulk of the flora, followed by chamaephytes, phanerophytes and hemicryptophytes. As part of the Saharo-Arabian region, the...
Environment and vegetation in the montane Saint Catherine area, south Sinai, Egypt
Journal of Arid Environments, 1996
The main aim of this study was to elucidate the complex interrelations between elevation, edaphic features, topography, prevailing wind speed and vegetation distribution on Saint Catherine mountains. Vegetation sampling was carried out at 37 stands distributed on five main mountains, and the cover percent of each species was recorded in five plots (5 ϫ 5 m) for each stand. Basic environmental information included elevation, slope degree, exposure, soil texture, nature of soil surface and speed of wind. Analysis of data involved two steps: first the vegetation matrix was classified by TWINSPAN producing six main communities: (1) Tanacetum santolinoides, (2) Artemisia inculta, (3) Artemisia inculta-Atraphaxis spinosa, (4) Artemisia inculta-Lycium shawii, (5) Artemisia inculta-Fagonia mollis, and (6) Artemisia inculta-Achillea fragrantissima. The data were summarized in two vectors of ordination scores produced by detrended correspondence analysis (DECOR-ANA) and canonical correspondence analysis (CANOCO). The second step involved relating the ordination scores to environmental parameters by correlation analysis. Classification analysis clarified the diversity of plant communities and related them to the environmental variations from Fagonia mollis on the driest and lowest elevation stands to Tanacetum santolinoides and Artemisia inculta communities on wet and windy sites at high elevations. The distribution of plants is largely determined by a moisture gradient which is controlled by elevation, slope degree, soil texture (fine sand and coarse sand fractions), and the speed of winter and summer wind, as well as the nature of the soil surface. The nature of the soil surface in the form of boulders and stones, and cobbles and surface gravel is one of the most important factors controlling moisture availability and subsequently the distribution of plant communities in the mountains.
Vegetation analysis of Wadi Al-Jufair, a hyper-arid
Wadi Al-Jufair, a tributary of Wadi Nisah, is one of the important wadis of Najd region (Saudi Arabia) sheltering a rich diversity of higher plants. The study area is extended into approximately 15 km 2 encompassing the commonest geomorphological features encountered in desert wadis. The wadi supports several rare plants, including Maerua crassifolia Forssk., a regionally endangered tree, and Acacia oerfota (Forssk.) Schweinf., a rare shrub with restricted distribution. The present study aims to analyze the vegetation of wadi Al-Jufair and propose its designation as an important plant reserve. The vegetation type is fundamentally of chamaephytic nature with some phanerophytes, and distinguished into associations where the dominant perennial species give the permanent character of plant cover in each habitat. Four vegetation groups were identified with the application of TWINSPAN, DCA and CCA programs and named after the characteristic species as follows: Lycium shawii; A. oerfota; Acacia raddiana-Rhazya stricta and Artemisia monosperma. These plant associations demonstrate significant variation in soil texture, moisture, organic matter, pH, EC, and minerals of Wadi Al-Jufair.
International Journal of Innovation and Applied Studies, 2014
The study was conducted during 2013 in Bouchebka, located in the central west of Tunisia.Such territory has a typical landscape of the transfrontier region. The series of the forest in Bouchebka is a part of the great mass of Aleppo pine. It is distinguished by the importance of the forest area which covers 92 % of the surface area (19,700 ha). The study attempts to inventory the natural vegetation and characterize ecological terms while highlighting the importance of environmental conditions. The method is based on a phytoecological analysis to quantify the floristic richness and diversity of the ecosystem in the forest of mountains in Bouchebka on the basis of floristic surveys and transects distributed in a stratified, systematic sampling in different vegetation formations that were previously distinguished. Statistical analyzes were performed using the Factorial Correspondence Analysis (FCA). The results show that the forest is composed primarily of the Aleppo pine trees, these forests are characterized by the abundance of young feet (10-25 cm diameter class). The ecosystem includes 12 families and 17 genera, 26 species. Thus the study has identified that the biological spectrum of the study area is characterized by a clear dominance of shrubs (41%) and chamaephytes (32 %). The distribution of plant species is influenced by ecological features of the region: the results show that 82% of species are drought tolerant which shows the arid environment. The region is also characterized by its windy side: 32% of species spread via anemochory. Factor analysis showed a pastoral aspect in the study area, with a presence of cultured human action exerted on the forest land species. Phytological spectrum indicates a predominance of woody species reflecting a territory dominated by open grassy areas, predominantly reflecting an arid climate.
Vegetation-Soil Relationships in Wadi El-Rayan Protected Area, Western Desert, Egypt
The present study provides an analysis of the soil and vegetation composition at 10 sites in Wadi El Rayan Protected Area and concentrates on the environmental factors that affect plant species distribution. A total of 17 vascular plant species belonging to 13 botanical families was recorded. Poaceae, Chenopodiaceae, and Zygophyllaceae were the largest families identified. Chorological analysis revealed that 47% of the studied species are Pluri-regional, 41% are Bi-regional and 12% are Mono-regional. The recorded species extend their distribution all over the Saharo-Arabian (33%) followed by Irano-Turanian (24%), Mediterranean (22%), Palaeotropical (8%), Sudano-Zambezian (5%), Neotropical (5%), and Euro-Siberian (3%). The life-form spectrum revealed that the phanerophytes (35%) and geophytes helophytes (23%) are the most frequent, followed by chamaephytes (18%), therophytes (12%), hemicryptophytes (6%), and helophytes (6%). The dominant species were Phragmites australis, Tamarix nilotica and Zygophyllum album; while the co-dominant species were Juncus rigidus, Nitraria retusa, Alhagi graecorum, Typha domingensis, Zygophyllum coccineum and Eucalyptus camaldulensis. Variation in species diversity among different locations were evident, the Northeast of the Lower Lake(9 species), followed by the Southwest of the Lower Lake and the Northeast of the Upper Lake(6 species each) showed highest species richness, while the Southeast of the Lower Lake showed the lowest recorded species richness (one species). Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) Ordination techniques were used to examine the relationship between the vegetation and soil parameters; pH, electric conductivity, CaCO 3 , organic matter and relative concentrations of cations.CCA analysis showed positive correlations of species and sites along the most important ecological gradients. Both ordination techniques clearly indicated the importance of these ecological factors on the distribution of the vegetation pattern in the area.
Wadi Helo (WH), in the United Arab Emirates, is a famous archeological site and protected area in the Hajar Mountains in the Arabian Peninsula. We investigated effects of topography, aspect, and altitude on floral diversity and species composition in this heterogeneous, mountainous, and highly arid environment. Using twenty transects distributed from the mountains top to the wadi bed; eighty plots, 100 m2 each, were selected for vegetation analysis. Classification of vegetation using TWINSPAN showed three groups in the wadi bed and five in the mountains, each distinguished by different dominant species. Forsskaolaea tenacissima, Rhazya stricta, Tephrosia apolina, Notoceras bicorne, Acacia tortilis, and Fagonia indica were dominants of the microhabitats of the wadi bed. Gorges were dominated with Dodonaea viscosa and Lavandula subnoda. The other four groups were found on the mountain slopes and were associated with particular aspects (being north-, south-, west-, or east-facing). The dominant species for these different aspects were, respectively: Boerhavia elegans; Ochradenus aucheri and Helianthemum lippii; Moringa peregrina; and Euphorbia larica and Cenchrus ciliaris. Altitude showed highly significant positive relationship with species frequency (P <0.001). South-facing slopes had the highest species richness and concentration of dominance. We concluded that the distribution of dominant species was a reflection of their ecological requirements and adaptations. Seven plant species were recorded as new to the flora of the UAE. These, plus ten additional species that had been reported as rare in only one of the two published floras of the UAE were highlighted as meriting greater priority in conservation.