a b s t r a c tAbout one third of the earth's land surface is covered by deserts that have low and variable rainfall, nutrient-poor soils, and little vegetation cover. Here, we focus on the goods and services offered by desert ecosystems using the northwestern coastal desert of Egypt extending from Burg El-Arab to El-Salloum as an example. We conducted field surveys and collected other data to identify the goods services and provided by native plant species. A total of 322 native plant species were compiled. The direct services provided by these native plants included sources of food, medicine, and energy; indirect vegetation services included promotion of biodiversity, water storage, and soil fertility. The plant diversity in this ecosystem provided economic service benefits, such as sources of fodder, fuel-wood, and traditional medicinal plants. Changes in land use and recent ill-managed human activities may influence the availability of these services and strongly impact biodiversity and habitat availability. Although deserts are fragile and support low levels of productivity, they provide a variety of goods and services whose continuing availability is contingent upon the adoption of rational land management practices.

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The main objective of the present study was to assess the effect of cold and hot Nigella sativa seeds aqueous extracts (NSSCAE and NSSHAE, respectively) and Nigella sativa seeds crude powder (NSSCP) on germination, some growth parameters and chemical constituents of Lupinus termis L. in mixed cropping system. Proximate analysis of Nigella sativa seeds showed that it contains oil, crude protein and ash beside significant amounts of vital mineral elements. The germination percentage was notably decreasing with increasing the concentrations of NSSCAE and NSSHAE. The effect on hypocotyl (HL) and radicle lengths (RL) of L. termis seeds was highly recognized. The applied concentrations of NSSCP caused a significant decline in growth parameters of L. termis. In addition, there was an inverse proportional relationship between increasing NSSCP concentrations and chlorophyll a and b, carotenoids and total pigment content of leaves. The variation in some biochemical constituents of L. termis seeds as affected by different concentrations of NSSCP was documented. The study concluded that seeds of Nigella sativa adversely affect seed germination and seedling growth of L. termis.

Launaea is a polymorphic genus with inter- and intraspecific inconsistencies. The study aimed to revise the classification and identification of Launaea species in Egypt. The study also aimed to assess the inter- and intraspecific variation among taxa using macro- and micromorphological characters. Numerical analysis was carried out on 156 specimens, which were collected from 63 sites in Egypt. The results revealed that L. arabica, L. capitata, L. intybacea and L. spinosa were significantly (p-value < 2.2 × 10−16 ***) discriminated from the other species at a high dissimilarity level. Launaea acanthodes was correctly identified as Lactuca orientalis. The study supported the inclusion of L. intybacea, L. massauensis and L. nudicaulis within section Microrhynchus, the separation of L. angustifolia and L. arabica in two distinct species. Two biotypes of L. nudicaulis were morphologically differentiated. Launaea fragilis subsp. fragilis showed considerable plasticity and variability in various characters; therefore, L. tenuiloba was considered to be merely an ecotype of L. fragilis. Launaea mucronata comprises two subspecies; cassiniana and mucronata, differentiated by their pappus type, conspicuous secondary ribs of the inner achenes, and the number of spines on the polar area of pollen grains.

The present study determines the variation in the phytosociological structure of wadi Washka and wadi Nethely in the western Mediterranean region of Egypt. Four vegetation groups were recognized in wadi Washka (A: Hammada scoparia‐Plantago albicans, B: Scorzonera alexandrina‐Hammada scoparia, C. Scorzonera alexandrina‐Launaea resedifolia, D: Suaeda pruinosa‐Salsola tetrandra) and five in wadi Nethely (I: Gymnocarpos decandrum‐Helianthemum stipulatum, II. Scorzonera alexandrina‐Plantago albicans, III: Arisarum vulgare‐Thymelaea hirsuta, IV: Anabasis oropediorum‐Scorzonera alexandrina, V: Salsola tetragona‐Pancratium maritimum). Two phytosociological groups were recognized in addition to those identified in the previous studies. The first is codominated by Anabasis oropediorum and Scorzonera alexandrina and characterizes the plateau of wadi Nethely and the second is codominated by Arisarum vulgare and Thymelaea hirsuta and characterize the lower position near the cultivated bed of the wadi. Among soil factors affecting the distribution of vegetation groups are moisture content, Clay, CaCO3%, Ca++ and K+. Nomenclature follows Täckholm (1974).