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.

Silybum marianum (L.) Gaertn is an important medicinal plant and has been used as a traditional medicine for diseases of the liver and biliary tract. The effects of seed priming by H 2 O 2 (Haloprimig) and magnetic field (Magnetopriming, MF) on the impacts of seawater concentration were tested using S. marianum at the vegetative stage. These plant species accumulate flavonoids especially slimarine that is used in liver treatment. Some soaked S. marianum seeds were subjected to 0.18 T MF for different time durations (0, 10, 20 and 30 min) and other seeds were soaked in different concentrations of H 2 O 2 (0, 80,160 and 240μM) for 8h. H 2 O 2 priming increased growth and development under water irrigation more than under sea water stress. Moreover, our results uncovered statistical evidence that the priming seeds with H 2 O 2 and MF increased the tolerance of S. marianum to salinity. In summary, we provide clear evidence that seawater stress caused a highly significant reduction in the growth parameters and stimulation in proline and phenolic compounds. It was concluded that, application of H 2 O 2 and MF of S. marianum could scavenge or alleviate the harmful effects of salinity stress at early seedling stage and alleviate the oxidative damage leading to improvements in physiological attributes for the plant growth under sea water stress.

Intra-city railway areas are deemed large greenspaces and are believed to be key in enhancing the diversity and dynamics of urban flora. In the current study, the floristic composition and diversity along intra-city railway and tram tracks in Alexandria were surveyed. The floristic composition of the plant communities in relation to environmental factors, ecological indicators, and level of human impact was analyzed using multivariate analysis (two-way indicator species analysis (TWINSPAN) for classification and detrended correspondence analysis (DECORANA) for ordination. The multivariate ordination techniques (CCA) revealed differences in the environmental factors and climatic factors influencing the floristic composition of the railway and tram track habitats. Tram tracks suffered higher human impact while maintaining higher vitality and cover compared to train tracks. Species recorded were mainly therophytes, followed by phanerophytes and hemicryptophytes dominated by native species; however, invasive species’ contribution was higher compared to surrounding regions. The number of invasive species was greater in railway areas compared to tram track areas (19 and 15, respectively). The occurrence of two endemic species (Sinapis allionii and Sonchus macrocarpus) with limited national distribution highlights the importance of these habitats as valuable refuge areas for rare and endangered species worthy of conservation action.

The role of heritage sites as a shelter for biodiversity is overlooked. Eight archeological sites representing different landscapes in Alexandria City were surveyed, from which 59 stands were sampled between April 2019 and March 2021. The archeological sites and the relictual landscapes are geographically dispersed and are arranged here from west to east, representing the full range of environmental variation within the study area. The selection of stands in each site was based on the area and the variability within the habitats, the physiography, and the levels of disturbance. A composite soil sample was collected from each site. Two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DECORANA) were carried out to identify the plant communities in the study area. The recorded taxa, their national geographical distribution, life forms, habitats, chorological types, and vegetation groups are listed. A total of 221 specific taxa, 172 native and 49 alien non-native species (representing some 10.3% of the whole range of Egyptian flora), belonging to 150 genera and 44 families, are reported in the present study. Only two endemic species were recorded in the studied urban habitats. The phytosociological analysis of the sites showed differences among vegetation types found in the archeological sites as a function of the varying degrees of enthronization. A significant effect of archeological site and relictual landscape on species diversity was observed as indicated using the richness, Shannon’s and Simpson’s indices. Flat plains are substantially more diverse than any of the other habitats in the present study, followed by the habitat of rocky ridge slope. The present study found evidence of an ecological legacy that persists today within the semi-arid climatic ecosystem of Alexandria City. The study highlights the urgent need for measures to maintain cultural landscapes while considering the conservation of biodiversity within the archeological sites. It is hoped that the outcomes of the current study can provide guidance on the potential integration of biodiversity conservation in planning the management of archeological sites.

The eastern coastal area of the Arabian Peninsula is subject to overgrazing, agricultural activities, oil pollution and urban encroachments. These activities cause habitat destruction and may have changed species composition. The current study aimed at assessing conservation and ethnobotanical importance of plants and how they are affected by environmental threats. The natural vegetation composition was studied and the ethnobotanical relative importance (RI) index and the species conservation index (SCI) were calculated. The results showed that native plants provide many ecological and socioeconomic services, including the provisioning of food, medicine, and energy. The native species (>77%) were reported to potentially be used for more than 170 therapeutic applications and for curing various human ailments. The medicinal plants (15%) attained RI value >50% reflecting high versatility and importance in local pharmacopeia. The number of threats to species showed significant positive association with SCI index and insignificant positive association with RI index. The study indicated that the current human activities may have negatively impacted provisioning of ecosystem services especially those offered by native plants. The ability of the natural ecosystems to sustainably provide services will be enhanced by adoption of land management practices that restore species and reduce pressure on native plants.