Vegetation clustering along irrigation and drainage canal banks in an extreme arid area in Upper Egyp

Abstract

Vegetation analysis of the irrigation and drainage canals of the Aswan Province indicates the dominance of Pluchea dioscoridis, Phragmites australis, Cynodon dactylon, Imperata cylindrica, Alhagi graecorum, Sonchus oleraceus, Ceratophyllum demersum and Polypogon monspeliensis. The classification of stands according to the TWINSPAN technique resulted in seven vegetation clusters at level three. The seven clusters of level three are named after the dominant species as follows: (I) Sesbania sesban, (II) Chenopodium murale-Digitaria sanguinalis-Echinochloa colona, (III) Cyperus alopecuroides, (IV) Cynodon dactylon, (V) Phoenix dactylifera-Oxystelma alpini-Hyphaene thebiaca, (VI) Tamarix nilotica and (VII) Anagallis arvensis-Cuscuta pedicellata-Convolvulus arvensis-Chenopodium album. Among the estimated soil variables in the present study, sand, silt, Mg+2 and organic matter are important in characterising the vegetation clusters.