Comparative study on the adaptation of some natural plants grown under macronutrients limitation at North Sinai sand dunes (Egypt)

Natural vegetation on sand dunes located in North Sinai is exposed to several stress factors, such as: aridity, high light intensity, extreme temperature, nutrients limitations and sand accretion…, etc. Many plants have adapted, genetically, morphologically and physiologically to withstand stresses, partially or completely, with variable degrees between plant species. The sand dune system in El-Ssabha, El-Sheikh Zuwied, Abu-Asab, El-Hauol, El-Gapher and Magaria at the north of Sinai was studied phytosociologically and ecologically. Twenty-four plant species growing in the above mentioned locations were collected during 2007 and 2008. Plant root length/shoot length ratio, root dry weight/shoot dry weight percentage, root and shoot water saturation deficit (W.S.D.) percentage, root and shoot succulence degree percentage and the concentrations of: total chlorophyll pigments, proline, soluble carbohydrates, N, P, K, Na, Ca and Mg were measured. The results indicated that the climatic factors have significant role on the monthly and seasonally microhabitats. The great variety of coarse sand recorded in El-Ssabha sand dunes. Soil moisture percentage gave maximum percentage in wet season during the two years 2007 and 2008. Soil pH and soil E.C obtained varied according to the location. Ammophila arenaria were recorded in all sand dune locations. Generally, Boiaceae family gave the highest values for six plant species belong. Cressa cretica recorded the highest values of root/shoot length ratio and Ifloga spicata of root/shoot dry weight percentage. The mean values of roots and shoots water saturation deficit (W.S.D.) percentage and succulence degree percentage recorded 40.850, 37.555, 46.309 and 37.657, respectively. Total chlorophyll pigments, proline and soluble carbohydrates differ from species to another. Some macronutrients were highly concentrated in shoot system compared to root system. The relationships are highly significant simple correlation coefficients and simple regression equation between most parameters of plant species.