Soil Research Soil Research Society
Soil, land care and environmental research

Changes in surface water quality after inundation of acid sulfate soils of different vegetation cover

S. G. Johnston A , P. G. Slavich B C and P. Hirst A

A NSW Agriculture, Grafton Agricultural Research Station, PMB 2, Grafton, NSW 2460, Australia.

B NSW Agriculture, Wollongbar Agricultural Institute, Bruxner Highway, NSW 2477, Australia.

C Corresponding author. Email:

Australian Journal of Soil Research 43(1) 1-12
Submitted: 7 June 2004  Accepted: 4 October 2004   Published: 14 February 2005


Surface soils from an acid sulfate soil (ASS) backswamp were inundated in a temperature controlled environment and surface-water chemistry changes monitored. The soils had contrasting in situ vegetative cover [i.e. 2 grass species, Cynodon dactylon and Pennisetum clandestinum (Poaceae), and litter from Melaleuca quinquenervia (Myrtaceae)]. The different vegetation types had similar biomass and carbon content; however, there were large differences in the quality and lability of that carbon, which strongly influenced decay/redox processes and the chemical composition of surface waters. The grass species had more labile carbon. Their surface waters displayed rapid sustained O2 depletion and sustained low Eh (~0 mV), high dissolved organic carbon (DOC), and moderate pH (5–6). Their soil acidity was partially neutralised, sulfides were re-formed, and reductive dissolution of Fe(III) led to the generation of stored acidity in the water column as Fe2+(aq). In contrast, M. quinquenervia litter was high in decay-resistant compounds. Its surface waters had lower DOC and low pH (<4) and only underwent a short period of low O2/Eh. Soluble Al caused M. quinquenervia surface waters to have higher titratable acidity and soil pH remained consistently low (~3.8–4.0). Concentrations of Cl and Al in surface waters were strongly correlated to initial soil contents, whereas the behaviour of Fe and SO42– varied according to pH and redox status. This study demonstrates that changes in vegetation communities in ASS backswamps that substantially alter either (a) the pool of labile vegetative organic carbon or (b) the concentration of acidic solutes in surface soil can have profound implications for the chemical characteristics of backswamp surface waters.

Additional keywords: carbon decomposition, wetland biogeochemistry, anaerobic, iron reduction, drainage.


Achtnich C Bak F Conrad R 1995 Competition for electron donors among nitrate reducers, ferric iron reducers, sulfate reducers and methanogens in anoxic paddy soil. Biology and Fertility of Soils 19 65 72 DOI

Ahern CR McElnea A Baker DE 1998 Total actual acidity (TAA—Method 21F). ‘Acid sulfate soils laboratory methods guidelines’. Ahern CR Blunden B Stone Y Acid Sulfate Soils Management Advisory Committee Wollongbar, NSW

Armstrong W 1975 Waterlogged soils. ‘Environment and plant ecology’. Etherington JR 181 218 Wiley London

Ashraf M Yasmin H 1991 Differential waterlogging tolerance in three grasses of contrasting habitats: Aeluropus lagopoides (L.) Trin., Cynodon dactylon (L.) Pers. and Leptochloa fusca (L.) Kunth. Environmental and Experimental Botany 31 437 445

Bailey PCE Watkins SC Morris KL Boon PI 2003 Do Melaleuca ericifolia Sm. leaves suppress organic matter decay in freshwater wetlands? Archiv fuer Hydrobiologie 156 225 240 DOI

Baas Becking LGM Kaplan IR Moore D 1960 Limits of the natural environment in terms of pH and oxidation-reduction potentials. Journal of Geology 68 243 284

Benner R Moran MA Hodson RE 1986 Biogeochemical cycling of lignocellulosic carbon in marine and freshwater ecosystems: relative contributions of procaryotes and eukaryotes. Limnology and Oceanography 31 89 100

Bigham JM Schwertmann U Traina SJ Winland RL Wolf M 1996 Schwertmannite and the chemical modelling of iron in acid sulfate waters. Geochimica et Cosmochimica Acta 60 2111 2121

Blodau C Peiffer S 2003 Thermodynamic and organic matter: constraints on neutralisation processes in sediments of highly acidic waters. Applied Geochemistry 18 25 36 DOI

Boon PI Johnstone L 1997 Organic matter decay in coastal wetlands: an inhibitory role for essential oil from Melaleuca alternifolia leaves? Archiv fuer Hydrobiologie 138 433 449

van Breemen N 1973 Soil forming processes in acid sulphate soils. ‘Acid sulphate soils: Proceeding of the International Symposium on Acid Sulphate’. Dost H 66 129 International Institute for Land Reclamation and Improvement Wageningen, The Netherlands

van Breemen N 1975 Acidification and deacidification of coastal plain soils as a result of periodic flooding. Journal of the Soil Science Society of America 39 1153 1157

Chen RL Barko JW 1988 Effects of freshwater macrophytes on sediment chemistry. Journal of Freshwater Ecology 4 279 289

Cook FJ Hicks W Gardner EA Carlin GD Froggatt DW 2000 Export of acidity in drainage water from acid sulfate soils. Marine Pollution Bulletin 41 319 326

Dent D 1986 ‘Acid sulphate soils: a baseline for research and development.’ ILRI Publication No. 39. International Institute for Land Reclamation and Improvement Wageningen, The Netherlands

Goodrick GN 1970 A survey of wetlands of coastal NSW. CSIRO Technical Memorandum No. 5. (CSIRO: Canberra).

Greenway M 1994 Litter accession and accumulation in a Melaleuca quinquenervia (Cav.) S.T. Blake wetland in south-eastern Queensland. Australian Journal of Marine and Freshwater Research 45 1509 1519

Johnston SG Slavich P Sullivan LA Hirst P 2003 a Artificial drainage of floodwaters from sulfidic backswamps: effects on deoxygenation in an Australian estuary. Marine and Freshwater Research 54 781 795

Johnston SG Slavich PG Hirst P 2003 b Alteration of groundwater and sediment geochemistry in a sulfidic backswamp due to Melaleuca quinquenervia encroachment. Australian Journal of Soil Research 41 1343 1367 DOI

Johnston SG Slavich PG Hirst P 2004 The acid flux dynamics of two artificial drains in acid sulfate soil backswamps on the Clarence River floodplain, Australia. Australian Journal of Soil Research 42 623 637

Kawano M Tomita K 2001 Geochemical modelling of bacterially induced mineralisation of schwermannite and jarosite in sulfuric acid spring water. American Mineralogist 86 1156 1165

Kusel K Roth U Trinkwalter T Peiffer S 2001 Effect of pH on the anaerobic microbial cycling of sulfur in mining-impacted freshwater lake sediments. Environmental and Experimental Botany 46 213 223

Lin C Melville MD 1993 Control of soil acidification by fluvial sedimentation in an estuarine floodplain, eastern Australia. Sedimentary Geology 85 271 284 DOI

Lin C O’Brien K Lancaster G Sullivan LA McConchie D 2000 An improved analytical procedure for determination of total actual acidity in acid sulfate soils. The Science of the Total Environment 262 57 61 DOI

Lovely DR Phillips EJP 1987 Competitive mechanisms for inhibition of sulfate reduction and methane production in the zone of ferric iron reduction in sediments. Applied and Environmental Microbiology 53 2636 2641

Marschner B Kalbitz K 2003 Controls on the bioavailability and biodegradability of dissolved organic matter in soils. Geoderma 113 211 235

McClaugherty C Berg B 1987 Cellulose, lignin and nitrogen concentrations as rate regulating factors in late stages of forest litter decomposition. Pedobiologia 30 101 112

Miltner A Zech W 1998 Carbohydrate decomposition in beech litter as influenced by aluminium, iron and manganese hydroxides. Soil Biology and Biochemistry 30 1 7

Naylor SD Chapman GA Atkinson G Murphy CL Tulau MJ Flewin TC Milford HB Morand DT 1995 ‘Guidelines for the use of acid sulfate soil risk maps’. NSW Soils Conservation Service, NSW Department of Land and Water Conservation Sydney

NSW Agriculture and Fisheries 1989 Review of land and water management impacts on fisheries and agricultural resources in the Lower Macleay—Working Party Report. (NSW Agriculture and Fisheries: Wollongbar).

Peine A Tritschler A Kusel K Peiffer S 2000 Electron flow in iron-rich acidic sediment—evidence for an acidity driven iron cycle. Limnology and Oceanography 45 1077 1087

Polunin NVC 1984 The decomposition of emergent macrophytes in fresh water. Advances in Ecological Research 14 115 166

Ponnamperuma FN 1972 The chemistry of submerged soils. Advanced Agronomy 24 29 96

Postma D Jakobsen R 1996 Redox zonation: equilibrium constraints on the Fe (III)/SO4-reduction interface. Geochimica et Cosmochimica Acta 60 3169 3175

Pressey RL Middleton MJ 1982 Impacts of flood mitigation works on coastal wetlands in New South Wales. Wetlands (Australia) 2 27 44

Pressey RL 1989 Wetlands of the lower Clarence floodplain, northern coastal New South Wales. Proceedings of the Linnean Society of NSW 111 143 155

Rayment GE Higginson FR 1992 ‘Australian laboratory handbook of soil and water chemical methods.’ Inkata Press Sydney

Roden EE Wetzel RG 2002 Kinetics of microbial Fe (III) oxide reduction in freshwater wetland sediments. Limnology and Oceanography 47 198 211

Sammut J White I Melville MD 1996 Acidification of an estuarine tributary in Eastern Australia due to drainage of acid sulfate soils. Marine and Freshwater Research 47 669 684

Satawathananont S Patrick WH Moore PA 1991 Effect of controlled redox conditions on metal solubility in acid sulfate soils. Plant and Soil 133 281 290

Sullivan LA Bush RT McConchie DM 2000 A modified chromium reducible sulfur method for reduced inorganic sulfur: optimum reaction time for acid sulfate soil. Australian Journal of Soil Research 38 729 734

Stumm W Morgan JJ 1981 ‘Aquatic chemistry.’ Wiley and Sons New York

Thamdrup B 2000 Bacterial manganese and iron reduction in aquatic sediments. Advances in Microbial Ecology 16 41 84

Tulau MJ 1999 Acid sulfate soil management priority areas in the Lower Clarence Floodplain. Department of Land and Water Conservation.
NSW Government, Sydney.

Walker PH 1972 Seasonal and stratigraphic controls in coastal floodplain soils. Australian Journal of Soil Research 10 127 142

Warren LA Haack EA 2001 Biogeochemical controls on metal behaviour in freshwater environments. Earth-Science Reviews 54 261 320

Webster JR Benfield EF 1986 Vascular plant breakdown in freshwater ecosystems. Annual Review of Ecology and Systematics 17 567 594 DOI

White I Melville MD Wilson BP Sammut J 1997 Reducing acidic discharges from coastal wetlands in eastern Australia. Wetlands Ecology and Management 5 55 72 DOI

Wilson BP White I Melville MD 1999 Floodplain hydrology, acid discharge and change in water quality associated with a drained acid sulfate soil. Marine and Freshwater Research 50 149 157

Wright DJ Otte ML 1999 Wetland plant effects on the biogeochemistry of metals beyond the rhizosphere. Biology and Environment. Proceedings of the Royal Irish Academy. Section B: Biological, Geological, and Chemical Science 99 3 10

Zimmermann W 1990 Degradation of lignin by bacteria. Journal of Biotechnology 13 119 130

Rent Article Export Citation Cited By (17)