Middle asian arid and semi-arid rangelands with reference to other similar regions of the world

*INRA Documentation Montpellier (FRA) Diffusion du document : INRA Documentation Montpellier (FRA)International audienc

Environmental Contaminants of Asiatic Deserts Ecosystems in relation to Plants Distribution and Structure

The focus of this research is on the salt/metalliferous pollutants because of their extreme toxicity, carcinogenicity, wide distribution and slow biodegradation under the harsh arid/semiarid environments. The extent of pollution of surface water and plants by various contents of salts, traces of heavy metals is presented for different regions of Zerafshan River Basin and Kyzylkum Desert. Soils and water contaminated with cadmium, copper, lead, zinc, selenium, arsenic, molybdenum, manganese, chromium, various oxidizers (Mn, NO3-, Fe +3, Al +3, ClO3-), NH4 and organic pollutants show natural colonization by species that have strategies of avoidance or tolerance to salt/metal toxities. Mapping of plant colonists of salts/metal contaminated soils, seed reproduction and cellular structures of tolerant taxa named as metallohalophytes are examined in the light of present knowledge of such strategies. Electrolytic adsorption and in situ immobilization technologies for cleaning pollutants of mining contaminated soils and underground water are suggested. Phytoremediation technology in the present case may offer a cost-effective and ecologically sound alternative