Systems Analysis of Mediterranean Desert Ecosystems of Northern Egypt (SAMDENE)

Abstract

Natural and semi-natural ecosystems in many parts of the world are in the most serious danger of being degraded or lost through Man's mistaking short-term economic gains under temporarily favourable conditions for long-term stability. This is particularly obvious in arid and semi-arid regions where ill-advised land-use methods have led to profound and often irreversible changes. Under the austere conditions prevailing in such regions, the dynamic ecological equilibrium is fragile: minor changes in the physical environment entail dramatic changes in plant and animal life. These circumstances lead easily to desertification. Due to overexploitation of natural resources by Man (especially overgrazing, and overcutting of shrubs) in North Africa, desertification has proceeded at a rate of more than 100 square kilometres per year. There is a great need to establish scientific bases for the conservation and rational use of the resources of natural and semi-natural ecosystems, especially in regions fringing the deserts where these resources continue to disappear regularly and all too rapidly.The western Mediterranean desert of Egypt provides clear examples of such losses. As a result of the misuse of its resources, the region is producing at a rate that is probably far below its real potential. Agriculture (mainly barley cultivation) provides the livelihood for 74% of the population between Alexandria and Daba'a; this agriculture is either rain-fed (along most of the coastal strip), supplied by Nile and drainage-water mixed (Mariut Project, 500,000 feddan = 210,000 ha), or fed by irrigation and rainfall where Nile water is used as a supplementary source (Mariut Extension Project, 18,000 feddan). The most important land-use in terms of area, however, is animal husbandry (very largely sheep and goats, whose herding becomes more important and farming less important passing from the sea towards the interior). Actually there is overstocking, so that range vegetation is seriously depleted due to overgrazing and poor management.Various land-use policies have been tried in the past decades with varying degrees of success, though fig and olive cultivations, which act within the framework of the natural ecosystem and with minimum human intervention, have a remarkable record of viability.The Samdene Project (Systems Analysis of Mediterranean Desert Ecosystems of Northern Egypt) was conceived to bring together information on the Mediterranean desert ecosystems of northern Egypt. The Project involves the construction of predictive models simulating the major ecosystems of the region interms of energy flow and circulation of matter, and of spatial and temporal changes in plants and animals aswell as in soil features in relation to environmental variations.So he preliminary results are already offered on soil moisture, vegetation, effects of fencing, phenology, litter production, and soil fauna.