Vegetation structure and soil characteristics of five common geophytes in desert of Egypt

Abstract

Geophytes are kind of plants having the capability to survive under arid environmental conditions; parts of their bodies are dormant fleshy underground as bulbs, corms, tubers or rhizomes. The present study was designed to throw light on the ecological features of five representative geophytes, namely, Cyperus capitatus, Cyperus conglomeratus, Elymus farctus, Lasiurus scindicus and Panicum turgidum. The soil characteristics and the associated species of these geophytes are described in their natural habitats of coastal desert (Deltaic Mediterranean coast) and inland desert (Cairo-Suez desert road). A total of 119 species (65 perennials, 3 biennials and 51 annuals) belonging to 97 genera and 28 families constituted their floristic composition. Asteraceae, Poaceae, Fabaceae and Chenopodiaceae are the largest families. Therophytes and chamaephytes are the most abundant life forms. The chorological analysis of the study area revealed that 63.02% and 47.33% belong to Saharo-Arabian and Mediterranean taxa, respectively. The highest species richness value (1.42 species stand–1) is recorded in the coastal desert. The application of TWINSPAN analysis yielded six distinct vegetation groups (A, B, C1, C2, D1 and D2); each is linked to one or more of the studied geophyte plants. The main soil factors affecting the study geophytes are electrical conductivity, organic carbon, sulphates, chlorides and bicarbonates as well as its silt composite.