Hyperspectral Remote Sensing of Floristic Composition and Phytogeographical Distribution in Gebel El-Sibaie, El-Quseir, Egypt

Abstract

Our study aims to explore the flora of the Gebel El-Sibaie and utilizes hyperspectral remote sensing to enhance the assessment of plant diversity. We analyze vegetation elements, including floristic diversity, life form, lifespan, and phytogeographical affinities, and utilize hyperspectral remote sensing with an ASD spectroradiometer. A total of 60 species belong to 49 genera and 29 different families, with Fabaceae, Zygophyllaceae, and Asteraceae being the most characteristic families. The flora exhibits high monotypism,
with 40 genera and 19 families. Chamaephytes and therophytes are the most prevalent life forms. The common lifespan was for perennials. Acacia cyclocarapa, Leucaena leucocephala, and Prosopis juliflora were recorded as alien species for the first time in Al-Quseir. Phytogeographical analysis reveals that mono-regional elements are the most dominant chorotypes, with Saharo-Arabian taxa comprising approximately a quarter of the floristic structure. The study created a spectral library of 37 plants and soil samples from 22 sites. It found consistent spectral signatures across plants, especially in the visible and infrared regions. Phragmites australis, Leucaena leucocephala, and Paronychia argentea had higher reflectance. Furthermore, plants manage water stress differently, with higher visible reflectance associated with increased chlorophyll content and lower infrared reflectance resulting from water absorption. Soil properties like coarse sand enhance reflectance in the visible and NIR regions, while silt and clay boost absorption in the SWIR. Chemical factors, such as EC and mineral content, impacted spectral signatures.