التغيرات البيئيه للمسطحات المائيه في جنوب العراق إعتمادا على الدراسات البالينولوجيه

Abstract

Palynological techniques are useful in reconstructing past environments, especially when other sources of information are lacking. We have embarked on a palynological study of the wetlands in Southern Iraq in an attempt to determine the nature and extent of past plant communities and other conditions prior to the drying of the wetland in the 1990s. Ten 1-m depth cores were collected from selected locations in marshes and shallow open water wetlands in Mesopotamian wetlands of Southern Iraq. Pollen diagrams from three short cores from the Hawizeh wetlands serve as a reference because this site has not been drained. The palynomorphs in these cores were Gramineae, Chenopodiaceae, Typha, Isonandra lanceolata, Bursarea, Artocarpus, Ireantea, Arenga, Crinum, Palmae, Navia, Tofieldia, Ipomorea, Xyris, and Morus. Fungal spores including Polyporisporites, Pluricellaesporites palyadosporites, Fusiformisporites, Spegazzinites indicus, Diporisporites, Plochmopellinites, Lycoperdon, Miliolinites, Dryadosporites constrictus, and Trichothyrites padapakarensis were noteworthy. Charcoal was scattered through the cores and indicate activities associated with human settlements. Many other forms of cuticles, filaments, insects, algae, and foraminifera test linings were also recorded. A second set of pollen samples were analyzed from 160 soil samples from eight cores collected from the wetland area which was dried during the 1990s. These data show a mixture of pollen and spores that could be used to evaluate past vegetation, climatic, and ecological changes. Preliminary results indicated that chenopodiaceous have increased while germinate types have declined which probably reflected desertification and a trend towards a more aeolian landscape during the 1990s. It is hoped that these studies will be useful in establishing conditions of the wetlands prior to destruction and will assist in setting restoration goals in the future. Case studies of one deep borehole (153 m) near Amara city for evaluating late Quaternary history and dig of 3 m depth to evaluate ancient desertification by wetland dryness were taken for correlation and connection with this recent sediment.