Associate Professor Scott G. Johnston

Research interests / background

Scott Johnston's research explores the influence of hydrology and biogeochemistry upon water quality, particularly in wetlands and coastal floodplains. Dr Johnston has focused on quantifying and interpreting landscape-scale processes and the dynamic redox geochemistry occurring within alternately flooded wetland soils - especially in environments with acid sulfate soils.

This knowledge of landscape function has enabled him to work closely with industry, state and local governments to develop, assess and refine applied remediation techniques for acid sulfate soils. He was lead author of 'Restoring the balance: Guidelines for managing floodgates and drainage systems on coastal floodplains', which is a widely adopted industry benchmark for managing broad-acre acid sulfate soil drainage.

Current research efforts aim to greatly improve our understanding of the consequences of rising sea-levels for coastal wetland biogeochemistry. Sea-level rise is likely to cause increasing saline tidal inundation of coastal lowlands, triggering a host of complex hydro-geochemical transformations at the inundation fringe - especially for Fe, S and associated trace elements such as arsenic.

Specific areas of research include:

• Coastal floodplain hydrology and biogeochemistry: understanding shallow groundwater behaviour in tidal and seasonal freshwater wetlands; assessment of sediment hydraulic properties; quantifying the dynamics of acidity and trace element flux from acid sulfate soil landscapes.
• Biogeochemical redox cycling of Fe-S-C: investigating the biogeochemical cycling and spatial and temporal transformations of these of these elements, which is key to understanding the geochemistry and water quality within acid sulfate soil wetlands.
• Post-flood estuarine hypoxia: exploring relationships between post-flood estuarine hypoxia and altered floodplain hydrology via artificial drainage, floodplain vegetation and reductive geochemical processes.
• Plant-soil-water rhizosphere interactions: examining how plant-soil-water interactions modify sediment geochemistry in wetland environments.
• Arsenic in coastal floodplain sediments: unravelling the fundamental geochemical and hydrological processes the drive arsenic mobilisation and control its biogeochemical cycling within coastal lowlands.
• Effects of sea-level rise on coastal wetlands: exploring the implications of climate change induced sea-level rise for coastal floodplain wetland biogeochemistry and surface water quality.

Awards & Honours

• Australian Research Council Future Fellowship – 2011-2015
• Australian Research Council APDI Fellowship - 2008

Research grants

Category 1 Grants

ARC

• $709,212. Australian Research Council Future Fellowship (FT110100130). "Sea-level rise as a driver for arsenic mobilisation: unravelling the fundamental hydro-geochemical controls". 2011-2015
• $250,000. Australian Research Council Linkage grant (LP120100238). "Unravelling the rhizosphere redox-cycling of iron, sulfur and carbon in re-flooded acidic wetlands". 2012–2014. (Lead Investigator)
• $600,000. Australian Research Council (LP110100732) "Electron flow in iron hyper-enriched acidifying coastal environments: reaction paths and kinetics of iron-sulfur-carbon transformations" (Investigators: Bush R.T., Grice K., Moreau J.W., Sullivan L.A., Burton E.D., Rose A.L., Johnston S.G., McElnea A.E. and Ahern C.R.) 2011-2013
• $800,000. Australian Research Council (LE110100174) Innovative synchrotron science - program for access to the Australian National Beamline Facility and cutting-edge beamlines at international synchrotrons 2011-2012.
• $246,000. ARC grant (LP0882141)and APDI fellowship."Impacts of climate change on coastal floodplain wetland biogeochemistry and surface water quality" (Chief Investigator).

Other Category 1 Grants

• $25,850. Australia India Strategic Research Fund (ST060012). "Safe and sustainable use of arsenic contaminated aquifers in the upper Gangetic plain: establishing a multi-disciplinary Australian-Indian collaboration". 2012-2013

Other Grants

• $25,850. Australia India Strategic Research Fund (ST060012) "Safe and sustainable use of arsenic contaminated aquifers in the upper Gangetic plain: establishing a multi-disciplinary Australian-Indian collaboration". 2012-2013
• 56 hours. Australian Synchrotron Research Program (AS122/ANBF/5363) "An XAS study of iron mineralogical controls on arsenic mobility during simulated inundation of a contaminated floodplain." 2012 (Investigator).
• 72 hours. Australian Synchrotron Research Program (AS122/ANBF/4812) "Unraveling the impact of floodplain soil inundation on arsenic mobility: integrated synchrotron XAS and high-resolution pore-water analysis." 2012 (Investigator).
• $4,665. Australian Synchrotron Research Program (AS122/ANBF/4880) "An XAS study of arsenic reduction and thiolation during long-term anaerobic transformation of arsenic-rich schwertmannite". 2012 (Investigators: Burton E.& Johnston S.).
• 72 hours. Australian Synchrotron Research Program (AS111/ANBF/3271) "Reductive transformation of As-bearing jarosite by H2S: using Fe, As and S K-edge XAS analysis to resolve a critical reaction pathway." 2011 (Chief Investigator)
• $11,980. Australian Institute of Nuclear Science and Engineering (ALNGRA6635). "Reductive transformation of jarosite by H2S: determining the role of S mineralisation products on arsenic mobility". 2011 (Chief Investigator)
• 46 hours. Australian Synchrotron Research Program (AS112/XAS/3685) "Influence of humic acid on the speciation of iron and arsenic in sulfidogenic environments". 2011 (Investigator)
• 46 hours. Australian Synchrotron Research Program (AS112/XAS/3855) "Unraveling electron flow associated with iron and arsenic biogeochemistry in flooded soil". 2011 (Investigator)
• $20,000. Environment Trust Seeding, NSW Government Grant. (07/10-06/11) "What lies beneath? A new method to map sub-surface acidity." 2010 (Investigator)
• 101 hours. Australian Synchrotron Research Program (P2526 2010/2) "The effect of biogenic iron-sulfide formation on arsenic mobility in acid-sulfate wetlands: An integrated arsenic, iron and sulfur K-edge XAS study." 2010 (Investigator).
• 48 hours. Australian Synchrotron Research Program (P2509 2010/2) "Arsenic sorption to greigite: Using XAS to resolve sorption mechanisms." 2010 (Investigator).
• $26,000. Taiwan Synchrotron Light Source (2009-1-020-2) "Using X-ray absorption spectroscopy to unravel iron bio-mineralisation pathways in re-flooded acid-sulfate soils" 2009–2010 (Investigator).
• $14,535. Australian Institute of Nuclear Science and Engineering. "Controls on the reductive dissolution of natural jarosite in a tidally inundated acid sulfate soil wetland". 2010 (Investigator).
• $12,135. Australian Institute of Nuclear Science and Engineering. "Characterising nano-particulate iron minerals formed in acid sulfate soils following seawater inundation". 2010 (Investigator).

Publications:

Journal articles

2013

Burton E.D., Johnston S.G., Kraal P., Bush R.T., Claff S. (2013) Sulfate availability drives divergent evolution of arsenic speciation during microbially-mediated reductive transformation of schwertmannite. Environmental Science & Technology. 47, 2221 – 2229. (2012 ERAID 4674 – FOR MD)

Burton E.D., Johnston S.G., Planer-Friedrich B. (2013) Coupling of arsenic mobility to sulfur transformations during microbial sulfate reduction in the presence and absence of humic acid. Chemical Geology. 343, 12 – 24 (2012 ERAID 1893 – FOR 0402)

Wong V.N.L., Johnston S.G., Burton E.D., Bush R.T., Sullivan L.A. (2013) Seawater-induced mobilization of trace metals from mackinawite-rich estuarine sediments. Water Research 47, 821 – 832 (2012 ERAID 4694 – FOR MD)

Keene A.F., Johnston S.G., Bush R.T., Burton E.D., Sullivan L.A., Dundon M., McElnea A.E., Smith D., Ahern C.R., Powell B. (in press) Enrichment and heterogeneity of trace metals in redox interfacial coastal sediments. Chemical Geology, Corrected Proof, Accepted Manuscript. (2012 ERAID 1893 – FOR 0402)

2012

Burton E.D., Johnston S.G. (2012) Impact of silica on the reductive transformation of schwertmannite and the mobilization of arsenic. Geochim. Cosmochim. Acta. 96,135-153. (2012 ERAID 1898 – FOR 0402)

Johnston S.G., Burton E.D., Keene A.F., Planer-Friedrich B., Voegelin A., Blackford M., Lumpkin G. (2012) Arsenic mobilization and iron transformations during sulfidization of As(V)-bearing jarosite. Chemical Geology 334, 9-24 (2012 ERAID 1893 – FOR 0402)

Johnston S.G., Keene A.F., Burton E.D., Bush R.T., Sullivan L.A. (2012) Quantifying alkalinity generating processes in a tidally remediating acidic wetland. Chemical Geology 304-305: 106-116 (2012 ERAID 1893 – FOR 0402)

2011

Burton E.D., Bush R.T., Johnston S.G., Sullivan L.A., Keene A.F. (2011) Sulfur biogeochemical cycling and novel Fe-S mineralization pathways in a tidally re-flooded wetland. Geochimica et Cosmochimica Acta 75, 3434-3451 (2010 ERA ranking A*).

Burton E.D., Johnston S.G., Bush R.T. (2011) Microbial sulfidogenesis in ferrihydrite-rich environments: effects on iron mineralogy and arsenic mobility. Geochimica et Cosmochimica Acta 75, 3072-3087(2010 ERA ranking A*).

Claff S.R., Sullivan L.A., Burton E.D., Bush R.T. Johnston, S.G. (In press). Partitioning of metals in a degraded acid sulfate soil landscape; influence of tidal re-inundation. Accepted manuscript., Chemosphere. (2010 ERA Ranking A).

Johnston S.G., Keene A.F., Bush R.T., Sullivan L.A., Wong V.N.L. (2011) Tidally driven water column hydro-geochemistry in a remediating acidic wetland. Journal of Hydrology 409, 128–139 (2010 ERA ranking A*).

Johnston S.G., Keene A.F., Burton E.D., Bush R.T., Sullivan L.A. (2011) Iron and arsenic cycling in intertidal surface sediments during wetland remediation. Environmental Science and Technology 45 (6), 2179–2185 (2010 ERA Ranking A*)

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A., Isaacson L.S., McElnea A.E., Ahern C.R., Smith C.D., Powell B. (2011) Iron geochemical zonation in a tidally inundated acid sulfate soil wetland. Chemical Geology 280, 257–270. (2010 ERA ranking A*).

Keene A.F., Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., McElnea A.E., Ahern C.R., Powell B. (2011) Effects of hyper-enriched reactive Fe on sulfidisation in a tidally inundated acid sulfate soil wetland. Biogeochemistry 103, 263-279(2010 ERA ranking A).

Wong V.N.L., Johnston S.G., Burton E.D., Bush R.T., Sullivan L.A., Slavich P.G. (2011) Anthropogenic forcing of estuarine hypoxic events in sub-tropical catchments: Landscape drivers and biogeochemical processes. Science of the Total Environment 409, 5368–5375(2010 ERA ranking A).

2010

Burton E.D., Johnston S.G., Watling K., Bush R.T., Keene A.F., Sullivan L.A. (2010) Arsenic effects and behavior in association with the Fe(II)-catalysed transformation of schwertmannite. Environmental Science and Technology, 44 (6), 2016–2021. (2010 ERA ranking A*)

Johnston S.G., Burton E.D., Bush R.T., Keene A.F., Sullivan L.A., Smith D., McElnea A.E., Ahern C.R., Powell B. (2010) Abundance and fractionation of Al, Fe and trace metals following tidal inundation of a tropical acid sulfate soil. Applied Geochemistry, 25, 323–335. (2010 ERA ranking B)

Johnston S.G., Keene A.F., Burton E.D., Bush R.T., Sullivan L.A., McElnea A.E., Ahern C.R., Smith C.D., Powell B. (2010) Arsenic mobilisation in a seawater inundated acid sulfate soil. Environmental Science and Technology, 44 (6), 1968–1973. (2010 ERA ranking A*)

Keene A.F., Johnston S.G., Bush R.T., Burton E.D., Sullivan L.A. (2010) Reactive trace element enrichment in a highly modified, tidally inundated acid sulfate soil wetland: East Trinity, Australia. Marine Pollution Bulletin, 60 (4), 620-626. (2010 ERA ranking B)

Watling K.M., Burton E.D., Johnston S.G., Bush R.T., Sullivan L.A. (2010). Electrochemical analysis of highly reactive pyrite. ECS Transactions 28, 129-140.

Wong V.N.L., Johnston S.G., Burton E.D., Bush R.T., Sullivan L.A., Slavich P.G. (2010) Seawater causes rapid trace metal mobilisation in coastal lowland acid sulfate soils: implications of sea level rise for water quality. Geoderma, 160, 252-263 (2010 ERA ranking A)

Wong V.N.L., Johnston S.G., Bush R.T., Sullivan L.A., Clay C., Burton E.D., Slavich P.G. (2010) Spatial and temporal changes in estuarine water quality during a post-flood hypoxic event. Estuarine, Coastal and Shelf Science, 87, 73–82. (2010 ERA ranking A)

2009

Burton E.D., Bush R.T., Johnston S.G., Watling K., Hocking R.K., Sullivan L.A., Heber G.K. (2009) Sorption of arsenic(V) and arsenic(III) to schwertmannite.Environmental Science & Technology 43, 9202-9207.

Burton E.D., Bush R.T., Sullivan L.A., Hocking R.K., Mitchell D.R.G., Johnston S.G., Fitzpatrick R.W., Raven M., McClure S., Jang L.Y. (2009) Iron-monosulfide oxidation in natural sediments: Resolving microbially mediated S transformations using XANES, electron microscopy, and selective extractions. Environmental Science & Technology 43, 3128-3134.

Isaacson L.S., Burton E.D., Bush R.T., Mitchell D.R.G., Johnston S.G., Macdonald B.C.T., Sullivan L.A., White I. (2009) Iron(III) accumulations in inland saline waterways, Hunter Valley, Australia: Mineralogy, micromorphology and pore-water geochemistry. Applied Geochemistry 24, 1825-1834.

Johnston S.G., Burton E.D., Bush R.T., Keene A.F., Sullivan L.A., Isaacson L. (2009) Pore water sampling in acid sulfate soils: a new peeper method. Journal of Environmental Quality, 38, 2474-2477.

Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., Smith D., Martens M.A., McElneaA.E., Ahern C.R., Powell B., Stephens L.P., Wilbraham S.T., van Heel S., (2009). Changes in water quality following tidal inundation of coastal lowland acid sulfate soil landscapes. Estuarine, Coastal and Shelf Science 81, 257-266.

Johnston S.G., Hirst P., Slavich P.G., Bush R.T., Aaso T.(2009) Saturated hydraulic conductivity of sulfuric horizons in coastal floodplain acid sulfate soils: Variability and implications. Geoderma 151, 387-394.

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A., Smith D., Martens M.A., McElnea A.E., Wilbraham S.T. (2009). Contemporary pedogenesis of severely degraded tropical acid sulfate soils after introduction of regular tidal inundation. Geoderma 149, 335-346.

2008

Burton E.D., Bush R.T., Sullivan L.A., Johnston S.G., Hocking R.K. (2008). Mobility of arsenic and selected metals during re-flooding of iron- and organic-rich acid-sulfate soil. Chemical Geology 253, 64-73.

Burton E.D., Sullivan L.A., Bush R.T, Johnston S.G., Keene A.F. (2008). A simple and inexpensive chromium-reducible sulfur method for acid-sulfate soils. Applied Geochemistry 23, 2759-2766.

2005

Johnston S.G., Slavich P.G., Hirst P., (2005). Changes in surface water quality after inundation of acid sulfate soils with different vegetation cover. Australian Journal of Soil Research 43, 1-12.

Johnston S.G., Slavich P.G., Hirst P., (2005). The effects of controlled tidal exchange on improving drainage water quality in acid sulfate soil backswamps. Agricultural Water Management 73, 87-111.

Johnston S.G., Slavich P.G., Hirst P., (2005). Opening floodgates in coastal floodplain drains: effects on tidal forcing and lateral transport of solutes in adjacent groundwater. Agricultural Water Management 74, 23-46.

2004

Bush R.T., Sullivan L.A., Fyfe D., Johnston S.G., (2004). Redistribution of monosulfidic black oozes (MBO) by floodwaters in a coastal acid sulfate soil floodplain. Australian Journal of Soil Research 42, 603-607.

Johnston S.G., Slavich P.G., 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 (5), 623-637.

Johnston S.G., Slavich P.G., Hirst P. (2004). The effects of a weir on reducing acidflux from a drained coastal acid sulfate soil backswamp. Agricultural Water Management 69, 43-67.

2003

Johnston S.G., Slavich P.G., Hirst P. (2003). Alteration of groundwater and sediment geochemistry in a sulfidic backswamp due to Melaleuca quinquenervia encroachment. Australian Journal of Soil Research 14, 1343-1367.

Johnston S.G., Slavich P., Sullivan L.A., Hirst P. (2003). Artificial drainage of floodwaters from sulfidic backswamps: effects on deoxygenation in an Australian estuary. Marine and Freshwater Research 54, 781-795.

Conference proceedings

2012

Hirst P., Bush R., Slavich P., Johnston S.G. (2012) Effect of bushfire on soil geochemistry in Fe and organic rich (peat) acid sulfate soil material. In; "3rd National Conference on Acid Sulfate Soils". 6th-7th March 2012, Melbourne, Victoria.

Johnston S. G., Keene A. F., Burton E. D., Bush R. T., Sullivan L. A. (2012) Hydro-geochemical coupling in seawater inundated acid sulfate soils: mobilisation of arsenic and hysteresis in iron and sulfur cycling. In; "3rd National Conference on Acid Sulfate Soils". 6th-7th March 2012, Melbourne, Victoria.

Keene A.F., Johnston S.G., Burton E.D., Bush R.T., Sullivan L.A. (2012) Reductive biomineralisation of pedogenic jarosite in tidally inundated acid sulfate soils. In; "3rd National Conference on Acid Sulfate Soils". 6th-7th March 2012, Melbourne, Victoria.

Sullivan L., Watling K., Claff S., Bush R., Burton E., Johnston S.G., Ahern C., McElnea A. (2012) Assessing acid sulfate soil neutralising capacity: a new approach. In; "3rd National Conference on Acid Sulfate Soils". 6th-7th March 2012, Melbourne, Victoria.

Wong V.N.L., Triantafilis J., Johnston S.G., Nhan T., Sullivan L.A., Bush R.T., Burton, E.D., Slavich P.G., Hirst P. (2012) A new method to rapidly and accurately map acid sulfate soils: exploring the utility of an EM38. In; "3rd National Conference on Acid Sulfate Soils". 6th-7th March 2012, Melbourne, Victoria.

2011

Burton E.D, Johnston S.G., Bush R.T. (2011) The role of microbial sulfidogenesis in shaping iron-sulfur-arsenic interactions within floodplain soils. In: "Proceedings of the 21th Annual V.M. Goldschmidt Conference". 14-19 August 2011, Prague, Czech Republic (Geochemical Society, and European Society for Geochemistry).

Johnston S. G., Keene A. F., Burton E. D., Bush R. T., Sullivan L. A. (2011) Hydrological controls on acid generation and export in floodplain wetlands. In: "Proceedings of the SL & NZFSS Congress 2011". 26th - 30th September 2011, Brisbane Convention and Exhibition Centre, Brisbane, Queensland.

Keene A.F., Johnston S.G., Burton E.D., Bush R.T. (2011) As, Fe and S cycling during reductive biomineralisation of pedogenic jarosite In: "Proceedings of the 21th Annual V.M. Goldschmidt Conference". 14-19 August 2011, Prague, Czech Republic (Geochemical Society, and European Society for Geochemistry).

Wong V.N.L., Johnston S.G., Walsh S., Morris S., Burton E.D, Bush R., Sullivan L., Slavich, P. (2011) Episodic estuarine hypoxic events: integrating the biogeochemistry, hydrology and climate on a subtropical floodplain, eastern Australia. In: "Proceedings of the 21th Annual V.M. Goldschmidt Conference". 14-19 August 2011, Prague, Czech Republic (Geochemical Society, and European Society for Geochemistry).

Wong V.N.L., Walsh S., Johnston S.G., Morris S., Bush R., Sullivan L. (2011) Climate and landscape drivers of estuarine deoxygenation events. In 'Australia/New Zealand Geomorphology Group'. 31st January - 4th February 2011. Oamaru, New Zealand.

2010

Ahern C., Smith D., McElnea A., Bush R., Johnston S., Wilbraham S., Van Heel S., Keene A., Powell B., and Malone B. (2010) A national demonstration site for acid sulfate soil remediation in the Australian tropics – an overview of the East Trinity environmental success story. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Burton E.D., Bush R.T., Johnston S.G., Keene A.F., Sullivan L.A (2010) Sulfur biomineralisation across a spatio-temporal hydrogeochemical gradient in an acid sulfate soil wetland. In: "Proceedings of the 20th Annual V.M. Goldschmidt Conference". 13-18 June 2010, Knoxville, Tennessee (Geochemical Society, and European Society for Geochemistry).

Burton E.D., Bush R.T., Johnston S.G., Sullivan L.A., Keene A.F. (2010) Reductive sulfur biomineralisation in a re-flooded acid-sulfate soil landscape. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Bush R.T., Sullivan L.A., Burton E.D., Johnston S.G., Keene A.F., Wong V., Mosely L. (2010) Climate change impacts on acid sulfate soil landscapes. In: "Proceedings of the 20th Annual V.M. Goldschmidt Conference". 13-18 June 2010, Knoxville, Tennessee (Geochemical Society, and European Society for Geochemistry).

Bush R., Sullivan L., Johnston S., Burton E., Wong V., Keene A. (2010) Climate change: a frontier for acid sulfate soil research. In '19th World Congress in Soil Science: 1st – 6th August.' Brisbane

Hirst P., Slavich P., Johnston S., Walsh S. (2010) Assessment of saturated hydraulic conductivity in coastal floodplain acid sulfate soils In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A. (2010) Mobilisation of arsenic following sea-water inundation of acid sulfate soils. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A. (2010) Remediating coastal acid sulfate soils by tidal inundation: geochemical hysteresis of iron. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A. (2010) Seawater inundation of Fe-rich coastal lowlands – hydrogeochemical coupling and hysterisis at the tidal fringe. In: "Proceedings of the 20th Annual V.M. Goldschmidt Conference". 13-18 June 2010, Knoxville, Tennessee (Geochemical Society, and European Society for Geochemistry).

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A. Wong V.N.L. (2010) Mobilisation of groundwater arsenic at the tidal fringe: hydro-geochemical coupling in seawater inundated coastal lowlands. In: "The challenges of sustainable management: National Groundwater Conference 2010" 31 October – 4 November 2010, National Convention Centre, Canberra.

Keene A.F., Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., (2010) Reductive dissolution of natural jarosite in a tidally inundated acid sulfate soil: geochemical implications. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Keene A.F., Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., (2010) Sulfidisation processes in a reactive Fe-enriched acid sulfate soil, northeastern Australia. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Vithana C., Sullivan L., Bush R., Burton E., Johnston S. (2010) Evaluation of existing methods for assessing retained acidity in acid sulfate soil materials. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Watling K.M., McElnea A., Ahern C., Burton E.D., Johnston S.G., Keene A.F., Bush R.T., Sullivan L.A. (2010) Effectiveness of lime particle size in the neutralisation of sulfidic acid sulfate soil materials. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Wong V.N.L., Hirst P., Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., Slavich P.G. (2010) Impacts of sea level rise on the biogeochemistry of a coastal floodplain in eastern Australia. In: "Proceedings of the 19th World Congress of Soil Science, Brisbane". 1-6 August, Brisbane, Australia.

Wong V.N.L., Johnston S.G., Hirst P., Burton E.D., Bush R.T., Sullivan L.A., Slavich P. (2010) Sea-level rise impacts on coastal water quality: Interactions between porewater, surface- and shallow groundwater geochemistry. In: "The challenges of sustainable management: National Groundwater Conference 2010" 31 October – 4 November 2010, National Convention Centre, Canberra.

Wong V.N.L., Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., Slavich P.G. (2010) The effects of increasing salinity on exchange processes in coastal lowland acid sulfate soils. In '19th World Congress in Soil Science: 1st – 6th August.' Brisbane

2009

Burton E.D., Johnston S.G., Bush R.T., Sullivan L.A., Keene A.K., Watling K. (2009) Iron-sulfur biomineralisation and arsenic mobility in acid-sulfate wetlands. In: "Proceedings of the 19th Annual V.M. Goldschmidt Conference". 21–26 June 2009, Davos Switzerland (Geochemical Society and European Association for Geochemistry). Pg A179.

Isaacson L.S., Burton E.D, Bush R.T., Johnston S.G, Sullivan L.A.(2009). Biomineralisation of nano Fe(III) phases in inland waterways. "Proceedings of the 19th Annual V.M. Goldschmidt Conference". 21–26 June 2009, Davos Switzerland (Geochemical Society and European Association for Geochemistry). Pg A571.

Johnston S.G., Keene A.F., Bush R.T., Burton E.D., Sullivan L.A. (2009) Remediation of coastal acid sulfate soils by tidal inundation: Effectiveness and geochemical implications. In: "Proceedings of the 18th NSW Coastal Conference". 3-6 November, Ballina, NSW.

Wong V.N.L., Johnston S., Bush R., Sullivan L., Clay C. (2009) Geomorphic controls on post-flood water quality on a coastal floodplain. In "7th International Conference on Geomorphology: 6th – 11th July." Melbourne.

2008

Bush R.T., Burton E.D., Sullivan L.A. and Johnston S.G. (2008). Catalytic action of aqueous ferrous iron and sulfide on the transformation of iron oxides in acid sulfate soils. In: "Proceedings of the Joint Conference of the 6th InternationalAcid Sulfate Soil Conference and the Acid Rock Drainage Symposium". (Eds. C. Lin, S. Huang & Y. Li). 16-20 September 2008 Guangzhou China. (Guangdong Press Group). pp.259-260.

Bush R.T., Johnston S.G. Sullivan L.A., Burton E. D., Ahern C., Powell B., McElnea A. and Smith D. (2008). Impacts of climate change and sea-level rise on acid sulfate soils. In: "Proceedings of the Joint Conference of the 6th International Acid Sulfate Soil Conference and the Acid Rock Drainage Symposium". (Eds. C. Lin, S. Huang & Y. Li). 16-20 September 2008 Guangzhou China. (Guangdong Press Group). pp. 260.

Bush R.T., Johnston S.G., Toppler N., Hurst P., Burton E.D., Sullivan L.A. and Slavich P. (2008). Managing floodplain drains to reduce acid export from acid sulfate soil backswamps. In: "Proceedings of the Joint Conference of the 6th International Acid Sulfate Soil Conference and the Acid Rock Drainage Symposium". (Eds. C. Lin, S. Huang & Y. Li). 16-20 September 2008 Guangzhou China. (Guangdong Press Group). pp. 261.

Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., Smith D., Martens M.A., McElnea A.E., Ahern C.R., Powell B., Stephens L.P., Wilbraham S.T., van Heel S. (2008). A national demonstration site for innovative acid sulfate soil research, East Trinity. CRC CARE National Conference 2008, Adelaide.

Johnston S.G., Bush R.T., Sullivan L.A., Burton E.D., Smith D., Martens M.A., McElnea A.E., Ahern C.R., Powell B., Stephens L.P., Wilbraham S.T.,van Heel S.(2008). Improvements in water quality following restoring tidal exchange in and acidified, diked and drained estuarine catchment. In: "Proceedings of the 6th International Acid Sulfate Soil Conference"(Eds: C. Lin, S. Huang, Y. Li). Guangdong Press Group, China, pp. 74-78.

Martens M.A., Ahern C.R., Smith D., McElnea A.E., Wilbraham S.T., Stephens L.P., van Heel S., Johnston S.G. (2008) Returning the tide: Overview, concepts and background to the acid sulfate soil remediation at East Trinity, Cairns, Australia. In: "Proceedings of the 6th International Acid Sulfate Soil Conference" (Eds. C. Lin, S. Huang & Y. Li). Guangdong Press Group, China, pp.132-136.

2003

Aaso T., Rogers M., Johnston S. (2003) Remediation of Partridge Creek Acid Sulfate Soil Hot Spot. In "NSW Coastal Conference Proceedings, 4-7 November 2003, Port Panthers Club, Port Macquarie NSW." (Hastings Council: Port Macquarie.) pp. 1-7.

2002

Bush R.T., Sullivan L.A., Johnston S.G., Fyfe D., Claff S., Slavich P.G. (2002) Mobility of monosulfidic black oozes in coastal acid sulfate soil landscapes. In: "Sustainable Management of Acid Sulfate Soils. Fifth International Acid Sulfate Soil Conference, August, 25-30th, 2002, Tweed Heads, NSW." (Eds. B.C.T. Macdonald, A.F. Keene, G.Carlin and L.A. Sullivan), (Acid Sulfate Soil Working Group, International Union of Soil Sciences) pp. 105

Hirst P., Johnston S.G., Slavich P.G. (2002) Lateral salt seepage into shallow coastal aquifers from tidal drains. In: "Sustainable Management of Acid Sulfate Soils. Fifth International Acid Sulfate Soil Conference, August, 25-30th, 2002, Tweed Heads,NSW." (Editors. B.C.T. Macdonald, A.F. Keene, G. Carlin and L.A. Sullivan), (Acid Sulfate Soil Working Group, International Union of Soil Sciences)pp. 143-144

Johnston S.G., Slavich P.G., Hirst P. (2002) Deep flooding of sulfidic backswamps and artificial drainage - links to estuarine deoxygenation and scald formation. In: "Sustainable Management of Acid Sulfate Soils. Fifth International Acid Sulfate Soil Conference, August, 25-30th, 2002, Tweed Heads, NSW." (Editors. B.C.T. Macdonald, A.F. Keene, G. Carlin and L.A. Sullivan), (Acid Sulfate Soil Working Group, International Union of Soil Sciences) pp. 147-148

Johnston S.G., Slavich P.G., Hirst P. (2002) Floodgate and drainage system management, opportunities and limitations - an acid export perspective. In "Floodgate Design and Modification Workshop, Ballina, NSW, 14th August 2002." (Ed. S. Walsh.) (NSW Fisheries: Ballina.) pp. 59-73.

Johnston S.G., Slavich P.G., Hirst P. (2002) Hydrological effects of floodgate management on coastal floodplain agriculture. In: 'Australian Soil Science Society, NSW Branch, North Coast Soils Tour 21-22 November 2002.' (Wollongbar) pp. 6-17.

Johnston S.G., Slavich P.G., Hirst P. (2002) Melaleuca quinquenervia encroachment in sulfidic backswamps - links to increasing groundwater acidity. In: "Sustainable Management of Acid Sulfate Soils. Fifth International Acid Sulfate Soil Conference, August, 25-30th, 2002, Tweed Heads, NSW."(Editors. B.C.T. Macdonald, A.F. Keene, G. Carlin and L.A. Sullivan), (Acid Sulfate Soil Working Group, International Union of Soil Sciences) pp. 151-152

Johnston S.G., Slavich P.G., Hirst P. (2002) Sources of salinity in low elevation coastal floodplain soil landscapes and effects on cane yield. In: "Sustainable Management of Acid Sulfate Soils. Fifth International Acid Sulfate Soil Conference, August, 25-30th, 2002, Tweed Heads, NSW." (Editors. B.C.T. Macdonald, A.F. Keene, G. Carlin and L.A. Sullivan), (Acid Sulfate Soil Working Group, International Union of Soil Sciences) pp. 148-149

Johnston S.G., Slavich P.G., Hirst P. (2002) The acid flux dynamics of two artificial drains in sulfidic backswamps on the Clarence River floodplain, Australia - Management implications. In: "Sustainable Management of Acid Sulfate Soils. FifthInternational Acid Sulfate Soil Conference, August, 25-30th, 2002, Tweed Heads, NSW." (Eds: B.C.T. Macdonald, A.F. Keene, G. Carlin and L.A. Sullivan), (Acid Sulfate Soil Working Group, International Union of Soil Sciences) pp. 79-80

Books

Johnston S., Kroon F., Slavich P., Cibilic A. & Bruce A. (2003) Restoring the balance: Guidelines for managing floodgates and drainage systems on coastal floodplains. NSW Agriculture: Wollongbar, Australia, pp 1-47. ISBN 0 7347 1518 8.

Other Publications

2007

Johnston S.G. (2007) Reviewing indicators of sustainable agriculture: Final Report. NSW Department of Primary Industries, Wollongbar, pp 1-63.

2005

Johnston S.G. (2005) 'The hydrology, biogeochemistry and management of drained coastal acid sulfate soil backswamps in the lower Clarence River floodplain'. Ph.D. Thesis. pp. 345.

2004

Johnston S.G., Slavich P.G. and Hirst P. (2004) The hydrological effects of floodgate management on coastal floodplain agriculture, DAN13: Final report to Land and Water Australia. NSW Agriculture, Wollongbar.

Johnston S. (2004) Managing floodgates to improve drain water quality Floodgate and drain management on coastal floodplains leaflet 1. (NSW Agriculture: Wollongbar)

Johnston S. (2004) Managing drains to reduce acid export. Floodgate and drain management on coastal floodplains leaflet 2. (NSW Agriculture: Wollongbar)

Johnston S., Bruce A., Kroon F. (2004) Managing drains and tidal creeks for fish passage. Floodgate and drain management on coastal floodplains leaflet 3. (NSW Agriculture: Wollongbar)

Johnston S. (2004) Managing salt water when opening floodgates Floodgate and drain management on coastal floodplains leaflet 4. (NSW Agriculture: Wollongbar)

Johnston S. (2004) How leaky are your soils? Groundwater flow in acid sulfate soils. Floodgate and drain management on coastal floodplains leaflet 5. (NSW Agriculture: Wollongbar)

Johnston S. (2004) Floodgates and retention structures - choosing the right design. Floodgate and drain management on coastal floodplains leaflet 6. (NSW Agriculture: Wollongbar)

Johnston S., Slavich P., Hirst P. (2004) Shark creek acid sulfate soil study site - The effects of the weir at reducing acid export during 2003. (NSW Agriculture, Grafton). pp. 1-10.

2003

Johnston S.G., MacDonald B. (2003) Soil permeability can effect acid export and salt seepage. Australian Sugarcane 7 (2), 21-22.

Johnston S.G., Slavich P.G. (2003) Hydraulic conductivity - a simple field test for shallow coastal acid sulfate soils. (NSW Agriculture: Wollongbar, Australia.) pp. 1-9.

Johnston S.G., Slavich P., Hirst P. (2003c) Hydraulic conductivity in the sulfuric horizons at Partridge Creek acid sulfate soil hotspot. Report DAN13/1. (NSW Agriculture, Wollongbar, Australia). pp. 1-9.

1995

Johnston S.G. (1995) The effects of acid sulphate soils on water quality in the Maria River Estuary, NSW. Report to Hastings Council. Hastings Council, Port Macquarie. pp. 201.

Updated: 11 April 2013