COMPOSITION, DISTRIBUTION PATTERNS AND HABITAT DIVERGENCE OF STREET TREES IN THE GREATER CAIRO CITY, EGYPT ترکيب وأنماط توزيع وحيود أشجار الشوارع بموائل مدينة القاهرة الکبرى، مصر

Abstract

Species diversity of the tree flora of 38 districts in the Greater Cairo city was studied with reference to landscape differentiation of species make-up. Three main habitats including 14 sites with 263 sample plots were considered (35 urban parks, 76 road islands and 152 street verges). In total, 378 of vascular plant species belonging to 264 genera and 79 families were recorded in urban areas of the Greater Cairo city. The most species-rich (44.7%) families were Fabaceae (36 spp.), Asparagaceae, Poaceae (21 spp.), Moraceae (19 spp.), Asteraceae (17 spp.), Euphorbiaceae and Malvaceae (15 spp.), Arecaceae (14 spp.), Lamiaceae (11 spp.), whereas the remaining families (70) constituted together 193 species. Ficus (18 spp.) was the highest among the species-rich genera, followed by Euphorbia (11 spp.), Asparagus, Brachychiton, Callistemon, Citrus and Pinus (4 spp. each). 257 genera contained only 1-3 species e.g. Cereus, Koelreuteria, Strelitzia, Terminalia, Carica and Toona. Growth form spectra revealed that, the recorded trees (139 spp.) belonged to 32 families; shrubs (79 spp.) to 30 families, herbs and others (160 spp.) to 48 families.