Patterns of Floristic Diversity and Environmental Correlates of Some Succulent Plants in Egypt

Abstract

In a trial to compare the floristic composition of succulent plants of the arid region in countries neighboring to Egypt showed that Egypt had the highest number of succulents (82 species) followed by Palestine and Saudi Arabia (51 species for each), Libya (48 species) and Sudan (47 species). The 82 known succulent species in Egypt can be classified into 59 leafy succulents and 23 stem succulents. The most species rich succulent families are Chenopodiaceae followed by Aizoaceae then Zygophyllaceae, Crassulaceae, Orobanchaceae and Tamaricaceae. Floristic data matrix (59 stands and 137 species) was subjected to classification by Two-Way Indicator Species Analysis (TWINSPAN). In this study, the default option of the computer program CANOCO software version 3.12 was used for all ordinations. Soil physical and chemical analysis in each succulent species in each stand was occurred. TWINSPAN yield 8 vegetation groups: (A) Mesembryanthemum crystallinum-Mesembryanthemum nodiflorum group, (B) Haloxylon salicornicum-Polygonum equisetiforme-Deverra tortuosa-Carduncellus mareoticus group, (C) Anabasis articulata group, (D) Zygophyllum coccineum-Zilla spinosa group, (E) Zygophyl/um album group, (F) Zygophyl/um album-Senecio glaucus group, (G) Arthrocnemum macrostachyum group, and (H) Tamarix nilotica group. Among the selected 59 stands, 21 succulents have been recorded. The largest five succulent species that recorded the highest weights were Anabasis articulata, Haloxylon salicornicum, Zygophyllum coccineum, -, Arthrocnemum macrostachyum and Zygophyllum album. It showed that the succulents recorded their highest weights (rW) in the stands of the salt marshes of the Nile region followed by the stands of the Red Sea regions and poorly represented in the stands of South Sinai region. The species weight of A. articulata, recorded in 4 out of the monitored 6 regions, was the highest amongst other succulents. The highest electric conductivity was attained in areas of A. macrostachyum on the fringes of Qarun Lake. Keywords: Succulent plants, TWINSPAN, Vegetation groups, Arid region, Multivariate procedures, Soil analysis, Floristic composition, Succulent families.