Species composition and vegetation structure of coastal and desert habitats in a hyper-arid environment

Abstract

Environmental changes and anthropogenic activities have significantly altered plant species distributions and biodiversity in various regions of Egypt, contributing to habitat fragmentation and a decline in plant populations. This study provides a comprehensive assessment of vegetation diversity, species distribution, conservation status, and environmental relationships across diverse habitats in Egypt, including coastal regions (Hurghada and El-Arish) and inland deserts (Wadi El-Gemal and El-Galala). From 2023 to 2024, a vegetation survey was conducted across four study areas in Egypt using stratified random sampling; the survey involved 86 sampled plots, analyzing species composition, growth forms, and cover. A total of 45 species from 16 families were recorded, with Asteraceae, Amaranthaceae, and Zygophyllaceae being the most dominant. Species were classified as native or non-native, and their conservation status was determined based on the IUCN Red List criteria. Multivariate analyses (cluster analysis, Detrended Correspondence Analysis, and Canonical Correspondence Analysis) revealed seven distinct vegetation groups (A-G), which were significantly influenced by soil properties such as pH, electrical conductivity, and ion content. The study also calculated diversity indices, with average species richness (SR) of 4.5 ± 2.1 species per plot and a Shannon-Wiener Index (H') ranging from 0.38 to 1.99. Conservation status assessments showed that 95.5% of species were native, with two non-native species recorded. Several species, such as Anabasis articulata and Haloxylon salicornicum, were categorized as Vulnerable (VU), while others, including Panicum turgidum and Phragmites australis, were classified as Near Threatened (NT) or Least Concern (LC). The results of this study underscore the importance of understanding the complex relationships between plant communities and environmental factors to develop targeted conservation strategies. The findings also emphasize the need for continued monitoring and protection of both coastal and inland desert habitats in Egypt to mitigate the effects of environmental degradation and preserve biodiversity.