Diatoms as indicators of wetland salinity in the Upper South East of SouthAustralia

Authors
Citation
Kh. Taffs, Diatoms as indicators of wetland salinity in the Upper South East of SouthAustralia, HOLOCENE, 11(3), 2001, pp. 281-290
Citations number
48
Categorie Soggetti
Earth Sciences
Journal title
HOLOCENE
ISSN journal
09596836 → ACNP
Volume
11
Issue
3
Year of publication
2001
Pages
281 - 290
Database
ISI
SICI code
0959-6836(200105)11:3<281:DAIOWS>2.0.ZU;2-W
Abstract
Wetland degradation in the Upper South East of South Australia is an urgent management concern. Scant recent environmental data is available for the r egion and long-term monitoring data is lacking. Usually a palaeoecological analysis is able to reveal environmental change in the medium- to long-term past. However, the region is not conducive to palaeoecological investigati on due to a fluctuating upper groundwater aquifer and alkaline soils which have destroyed most microfossils. It was found that the diatom assemblage w as preserved in the wetlands of the region for the period of European settl ement. Analysis of the diatom assemblage enabled production of an inferred salinity curve. In combination with a small amount of historical informatio n that was available, the salinity trend for the wetlands, for the period o f European agricultural activities, was identified. It was found that, whil e groundwater salinity has been increasing, the wetland areas have experien ced a freshening of surface water. This is due to an increase of throughflo w of surface water, a result of constructed drainage systems flushing salts from the wetlands. Despite the freshening of wetlands they continue to deg rade due to the changed hydrology, an impact of the drainage structures.