Studies on the succession of vegetation on some islands and sand banks in the nile near Khartoum, Sudan
- Faculty of Science, University of Khartoum, Sudan
- Faculty of Science, University of Alexandria, Moharram Bey, Alexandria, U.A.R.
The main Nile near Khartoum contains a number of islands which differ in age, degree of soil stabilization, height in relation to flood-water mark and in the amount and composition of plant cover. These islands were studied with a view to understanding the sequence of colonization and succession. The initial stages occur on the newly exposed sand bars. A very thin vegetation cover of Tamarix nilotica occurs. The main habitat factor is soil mobility and the open soil texture. The successive stages are all characterized by a progressive increase of the silt content, an improvement of the water relations of the soil and greater soil stabilization. This improvement in soil conditions is associated with a distinct trend in the vegetation towards an increase in the number of species, the height of the tallest species and the amount of plant cover. The corresponding communities are: thin Glineto-Ambrosietum, Tamaricetum and Acacieto-Tamaricetum. The climax (or subclimax) occurs on the Nile banks and is represented by dense Acacietum. The role played by man in this succession is not clearly understood. The scanty evidence suggests that man's activities may be at least partly responsible for the succession of Tamaricetum by Acacieto-Tamaricetum.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie
- 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Plant Science
- 1 - Physical Sciences ; 2 - Environmental Science ; 3 - Ecology