The present study provided an investigation of the floristic analysis, vegetation composition and species distribution along 100 m intervals of the elevation gradient (1500 m a.s.l.- >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 vegetation belts along the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis 1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more than the others.

The present study provided an investigation of the floristic analysis, vegetation composition and species distribution along 100 m intervals of the elevation gradient (1500 m a.s.l.- >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 vegetation belts along the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis 1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more than the others.

The present study provided an investigation of the floristic analysis, vegetation composition and species distribution along 100 m intervals of the elevation gradient (1500 m a.s.l.- >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 vegetation belts along the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis 1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more than the others.

The present study provided an investigation of the floristic analysis, vegetation composition and species distribution along 100 m intervals of the elevation gradient (1500 m a.s.l.- >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 vegetation belts along the altitudinal gradient. The vegetation groups of the lower elevations occupied the negative side of Axis 1 while those of elaqsaa higher elevations occupied the positive end. CCA was applied to assess the relationships between soil parameters, species composition and vegetation groups. Altitude, coarse and fine sand fractions, magnesium and bicarbonates had significant correlations with diversity indices more than the others.

Abstract Samples of Citrullus colocynthis shoots were collected from nine stands during two seasons (winter and summer 2015) in two tributaries of Wadi Qena (W. El-Atrash and W. El-Ghuza) in the Eastern Desert of Egypt. Soil of these stands was characterized by slight alkalinity and low soil moisture and organic matter percentages. Soil macronutrients were arranged as Ca>K> Na>Cl>SO4>Mg>PO4. However, in C. colocynthis tissues, these nutrients accumulated in the following order: SO4 >K > Ca > Mg > Na> Cl > PO4. The plant chlorophyll contents (Chl. a and b), their ratio and their stability index (CSI) increased drastically during summer. Shoot accumulated SO4, PO4 and all cations during summer more than winter, except Cl that was higher during winter. Soluble sugars (SS) and soluble proteins (SP) increased during summer while total free amino acids were higher during winter. Data revealed that there were close relationships between the high SO4, K and Ca contents and the hot-dry conditions and the accumulation of SS and SP on the relatively hot-dry season However, this may be primarily related to metabolism of drought resistance in such desert plants. Correlations between plant and soil variables showed important positive relations between soil Ca, Mg and plant Mg and between soil SO4 with Ca and Mg of plant. Spatial distribution of C. colocynthis was the most important factor that controls WC, Na, K, Ca, Mg, Cl, PO4, CSI a, CSI b , Chl. a and b, Chl. a/b ratio, TAA, , SS and SP. While, the interaction between both factors, spatial and temporal, could be the promoter.

Abstract Samples of Citrullus colocynthis shoots were collected from nine stands during two seasons (winter and summer 2015) in two tributaries of Wadi Qena (W. El-Atrash and W. El-Ghuza) in the Eastern Desert of Egypt. Soil of these stands was characterized by slight alkalinity and low soil moisture and organic matter percentages. Soil macronutrients were arranged as Ca>K> Na>Cl>SO4>Mg>PO4. However, in C. colocynthis tissues, these nutrients accumulated in the following order: SO4 >K > Ca > Mg > Na> Cl > PO4. The plant chlorophyll contents (Chl. a and b), their ratio and their stability index (CSI) increased drastically during summer. Shoot accumulated SO4, PO4 and all cations during summer more than winter, except Cl that was higher during winter. Soluble sugars (SS) and soluble proteins (SP) increased during summer while total free amino acids were higher during winter. Data revealed that there were close relationships between the high SO4, K and Ca contents and the hot-dry conditions and the accumulation of SS and SP on the relatively hot-dry season However, this may be primarily related to metabolism of drought resistance in such desert plants. Correlations between plant and soil variables showed important positive relations between soil Ca, Mg and plant Mg and between soil SO4 with Ca and Mg of plant. Spatial distribution of C. colocynthis was the most important factor that controls WC, Na, K, Ca, Mg, Cl, PO4, CSI a, CSI b , Chl. a and b, Chl. a/b ratio, TAA, , SS and SP. While, the interaction between both factors, spatial and temporal, could be the promoter.

Abstract Samples of Citrullus colocynthis shoots were collected from nine stands during two seasons (winter and summer 2015) in two tributaries of Wadi Qena (W. El-Atrash and W. El-Ghuza) in the Eastern Desert of Egypt. Soil of these stands was characterized by slight alkalinity and low soil moisture and organic matter percentages. Soil macronutrients were arranged as Ca>K> Na>Cl>SO4>Mg>PO4. However, in C. colocynthis tissues, these nutrients accumulated in the following order: SO4 >K > Ca > Mg > Na> Cl > PO4. The plant chlorophyll contents (Chl. a and b), their ratio and their stability index (CSI) increased drastically during summer. Shoot accumulated SO4, PO4 and all cations during summer more than winter, except Cl that was higher during winter. Soluble sugars (SS) and soluble proteins (SP) increased during summer while total free amino acids were higher during winter. Data revealed that there were close relationships between the high SO4, K and Ca contents and the hot-dry conditions and the accumulation of SS and SP on the relatively hot-dry season However, this may be primarily related to metabolism of drought resistance in such desert plants. Correlations between plant and soil variables showed important positive relations between soil Ca, Mg and plant Mg and between soil SO4 with Ca and Mg of plant. Spatial distribution of C. colocynthis was the most important factor that controls WC, Na, K, Ca, Mg, Cl, PO4, CSI a, CSI b , Chl. a and b, Chl. a/b ratio, TAA, , SS and SP. While, the interaction between both factors, spatial and temporal, could be the promoter.

TWELVE stands of Aerva javanica shrubs were visited during the winter and summer seasons of 2015 in two tributaries of WadiQena (Wadi El-Atrash and Wadi El-Ghuza) in the Egyptian Eastern Desert. Soil analysis showed low contents of soil moisture (SMC) and organic matter and slight alkalinity. Chlorophyll contents (Chl. a & b) and their ratio increased significantly during summer season, while their stability index increased during winter. The contents of Ca and K were high during summer, while PO4 and Na were higher during winter.Soluble sugars and soluble proteins increased during summer while total free amino acids were higher during winter. It can be concluded that there are close relationships between the high K, Ca and Cl contents and the hot-dry conditions prevailed in the summer season, and the accumulation of soluble sugars (SS) and soluble proteins (SP) on the relatively humid-cold season. Statistical correlations showed important positive relations between soil Na and plant water content (PWC), chlorophyll parameters, SS and SP. Fortunately, there was negative relation between soil PO4 and the contents of Na and Cl in the shoots. Spatial variations were the most important factor that controls A. javanica PWC, Na, K, Ca, Cl, PO4, Chl. a and b, SS and SP. While, Mg, chlorophyll a stability index (CSI a), CSI b and total amino acids (TFAA)were affected by the variation in both spatial and temporal gradients.

TWELVE stands of Aerva javanica shrubs were visited during the winter and summer seasons of 2015 in two tributaries of WadiQena (Wadi El-Atrash and Wadi El-Ghuza) in the Egyptian Eastern Desert. Soil analysis showed low contents of soil moisture (SMC) and organic matter and slight alkalinity. Chlorophyll contents (Chl. a & b) and their ratio increased significantly during summer season, while their stability index increased during winter. The contents of Ca and K were high during summer, while PO4 and Na were higher during winter.Soluble sugars and soluble proteins increased during summer while total free amino acids were higher during winter. It can be concluded that there are close relationships between the high K, Ca and Cl contents and the hot-dry conditions prevailed in the summer season, and the accumulation of soluble sugars (SS) and soluble proteins (SP) on the relatively humid-cold season. Statistical correlations showed important positive relations between soil Na and plant water content (PWC), chlorophyll parameters, SS and SP. Fortunately, there was negative relation between soil PO4 and the contents of Na and Cl in the shoots. Spatial variations were the most important factor that controls A. javanica PWC, Na, K, Ca, Cl, PO4, Chl. a and b, SS and SP. While, Mg, chlorophyll a stability index (CSI a), CSI b and total amino acids (TFAA)were affected by the variation in both spatial and temporal gradients.

TWELVE stands of Aerva javanica shrubs were visited during the winter and summer seasons of 2015 in two tributaries of WadiQena (Wadi El-Atrash and Wadi El-Ghuza) in the Egyptian Eastern Desert. Soil analysis showed low contents of soil moisture (SMC) and organic matter and slight alkalinity. Chlorophyll contents (Chl. a & b) and their ratio increased significantly during summer season, while their stability index increased during winter. The contents of Ca and K were high during summer, while PO4 and Na were higher during winter.Soluble sugars and soluble proteins increased during summer while total free amino acids were higher during winter. It can be concluded that there are close relationships between the high K, Ca and Cl contents and the hot-dry conditions prevailed in the summer season, and the accumulation of soluble sugars (SS) and soluble proteins (SP) on the relatively humid-cold season. Statistical correlations showed important positive relations between soil Na and plant water content (PWC), chlorophyll parameters, SS and SP. Fortunately, there was negative relation between soil PO4 and the contents of Na and Cl in the shoots. Spatial variations were the most important factor that controls A. javanica PWC, Na, K, Ca, Cl, PO4, Chl. a and b, SS and SP. While, Mg, chlorophyll a stability index (CSI a), CSI b and total amino acids (TFAA)were affected by the variation in both spatial and temporal gradients.