Tuesday, 8 November 2005 - 8:30 AM
202-1

Soil Chemistry Indicators of Wetland Degradation and Restoration Success in the Mesopotamian Marshes of Iraq.

Curtis Richardson, Duke University, Nicholas School of the Environment and Earth Sciences, Box 90333, Durham, NC 27708-0333

The first field evidence of water quality and soil conditions in the totally drained Central, re-flooded Al Hammar, and remaining natural Al Hawizeh marshes of southern Iraq after the war indicate that successful wetland restoration is occurring in some regions but is limited in others areas mostly due to high saline and sulfur soil conditions resulting in poor marsh vegetation reestablishment. The highest quality water, soil conditions and native marsh vegetation was found in the remaining Al Hawizeh marsh on the Iranian border and although significantly reduced in area it has the potential to be a native repopulation center for the region. Principal Component Analysis (PCA) revealed that marsh drainage and re-flooding resulted in significant changes in soil chemistry and moisture, with the re- flooded Al Sanaf marsh (diked but with no outflow) having much high soil salinities (26 vs. 1.8 mS/cm), sulfate content (1.8 vs. 0.30 mg/g) and lower soil moisture (21% vs. 42%) than the natural marshes. The soil chemistry of the re-flooded Al Hammar marshes most closely resembled that of the natural Al Hawizeh marshes, whereas the soil chemistry of the Al Sanaf and Central marshes were substantially different in terms of total metals and soil organic matter from the Hawizeh marshes. Severe saline conditions, Se concentrations and water quality degradation is occurring in some re-flooded marshes with no outflow. An analysis of soil and water conditions in 2004 in Abu Zarag and Suq Shuyukh, two restored wetland areas, revealed different geochemical conditions, which is leading to variations in the return of native species. Little or no long-term reestablishment of native reed (Phragmites australis) vegetation will occur unless restored wetlands are hydraulically designed to allow sufficient flushing of water through the ecosystem to reduce salinity levels and metal buildup in the soils and water.

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