The changes in species diversity and composition of Cyperus conglomeratus plant community caused by anthropogenic disturbance were estimated and analyzed in four selected sites at southern Jeddah in Saudi Arabia. The ecological disturbances in the study area have their major effect on species richness, where about 76% of the perennial species in the study area were disappeared as the result of the human impact on C. conglomeratus community in the most disturbed sites. Interspecific competition results from C. conglomeratus indicated that it is a competitor species led to exclusion of the other species from the highly disturbed sites which affected by the Industrial City in Jeddah. Therefore, resulting in a remarkable decrease in species diversity (Shannon’s index = 0.664) coinciding with maximum dominance of C. conglomeratus (Simpson’s index = 0.656). The general trend of plant species richness and diversity in moderately disturbed sites in the study area showed remarkable increase in both richness (S = 16 species) and diversity (Shannon’s index = 1.792), coinciding with minimum dominance (Simpson’s index = 0.253). The resulting graphs of species abundance distribution models representing the highly disturbed sites tend toward geometric series pattern of species abundances, where one (C. conglomeratus) species dominate the community with the remainder fairly uncommon, assuming competitive exclusion and resource exhaustion in such degraded and harsh ecosystems.

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.

This review evaluates the cytotoxic potential of the Sesbania genus, with a focus on Sesbania sesban, Sesbania grandiflora, and Sesbania cannabina. These species, known for their diverse phytochemical compositions, exhibit notable cytotoxic effects that suggest their utility in natural cancer treatments. Compounds such as quercetin, kaempferol, and sesbagrandiforian A and B have been highlighted for their strong antioxidant and antiproliferative effects, further emphasizing their therapeutic potential. The genus Sesbania exhibits a wide range of in vitro and in vivo bioactivities. Extensive research on S. grandiflora has uncovered mechanisms such as the activation of caspase cascades and the induction of apoptosis, attributed to its rich content of flavonoids and alkaloids. Notably, sesbanimides derived from S. grandiflora seeds have demonstrated potent cytotoxic effects by disrupting mitochondrial function. While S. sesban and S. cannabina have been less extensively studied, early findings highlight their potential through the inhibition of key cancer pathways and the identification of bioactive compounds such as galactomannan derivatives and 2-arylbenzofurans. Notably, the galactomannan derivatives from S. sesban exhibit significant immune-modulating properties. Additionally, nanoparticles synthesized from Sesbania species, including Cadmium oxide and PEGylated silver nanoparticles, have demonstrated promising cytotoxic activity by disrupting mitosis and enhancing immune responses. While further research is warranted, the Sesbania genus offers a promising basis for the development of innovative anticancer therapies.

Endemic species on mountains often have narrow altitudinal ranges and are more threatened at the higher altitudes, especially with climate changes. However, plants could use special microhabitats at the mountain tops as proper places for surviving the climate change (i.e., refugia). We assessed population attributes of three critically endangered endemic species (Primula boveana Decne ex Duby, Rosa arabica Crep., and Silene leucophylla Boiss.) in two growing seasons (2006/2007 and 2013/2014), differing in the received rainfalls in microhabitats at the high mountains of southern Sinai. Both P. boveana and S. leucophylla had very small population size, but significantly increased in the 2013/2014 growing season which received above average rainfalls. The population of R. arabica is the smallest (around 40 individuals) and did not increase, even after the increase in rainfalls. Whereas P. boveana is present in fewer sites and grew in small number of specific microhabitats, both S. leucophylla and R. arabica were recorded in most studied sites and habitat types. Unlike R. arabica, both P. boveana and S. leucophylla were recorded in caves and steep slopes and on the top of the mountains. This indicates that these sheltered mist microhabitats are the best for future conservation of these species after climate change.

Sesuvium portulacastrum is a perennial halophyte of family Aizoaceae, non-native to Egypt, which was introduced from France ten years ago as an ornamental species. This study reports the detection of S. portulacastrum in the wild in Egypt. Voucher specimens were deposited in the Herbarium of Alexandria University (ALEX). A population of the species was recorded in the wild near Maruit Lake in the north-western coast of Egypt in 2018 during plant resources surveys of the region. The study aimed to assess the potential for S. portulacastrum to spread as an alien species through field observations and geospatial measurements under current conditions in its new habitat. The measured morphological parameters were higher than those recorded in its native habitats. The field observation for three years revealed that the species is proliferating and expanding in the investigated site forming large mats of mean size of up to 9 m². The spatial extent of S. portulacastrum based on the EOO and AOO was quantified, and the expansion rate was estimated at 0.16 ha/year in the investigated site. The geospatial parameter used in the study will not only help in determining the spread rate of the alien species spatially and temporally, but also in its effective management through guiding managers in developing monitoring plans for the species under the changing climate uncertainty. Continuous monitoring and early detection of any potential threats of the introduced species are highly recommended, to avert any potential adverse impacts on native biodiversity and assess its behaviour in the wild habitat.