Drying and re-wetting of organic wetland sediments: Biogeochemistry and implications for wetland management
Date of Award
Doctor of Philosophy
School of Natural Sciences
Faculty of Computing, Health and Science
Associate Professor Pierre Horwitz
In the past decade, increasing instances of eutrophication and acidification of wetlands on the Swan Coastal Plain (SCP), Western Australia, and particularly on the Gnangara groundwater mound, have coincided with gradually decreasing ground- and surface water levels. The processes involved in determining whether a wetland will acidify or become eutrophic (or both) as a result of drawdown are still poorly understood, especially on the SCP where there are strong links between wetland water quality and underlying geomorphology. For instance, many of the wetlands located on the wellbuffered geomorphic unit called the Spearwood dunes are eutrophic due to high nutrient loads, and drying appears to exacerbate this. On the other hand, many of the wetlands on the leached and poorly buffered geomorphic unit called the Bassendean dunes also have relatively high nutrient inputs but are not eutrophic, and drying appears to cause acidification. However, an increasing number of wetlands on the Spearwood dunes are now also becoming acidified due to lowered groundwater tables.
Sommer, B. (2006). Drying and re-wetting of organic wetland sediments: Biogeochemistry and implications for wetland management. https://ro.ecu.edu.au/theses/98