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

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.

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Modelling the effects of climate on long-term patterns of dissolved organic carbon concentrations in the surface waters of a boreal catchment

Hydrology and Earth System Sciences ◽

10.5194/hess-12-437-2008 ◽

2008 ◽

Vol 12 (2) ◽

pp. 437-447 ◽

Cited By ~ 26

Author(s):

M. N. Futter ◽

M. Starr ◽

M. Forsius ◽

M. Holmberg

Keyword(s):

Surface Water ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Surface Waters ◽

Organic Soils ◽

Catchment Scale ◽

Changing Climate ◽

Recovery From Acidification ◽

Carbon Concentrations ◽

Process Based Models

Abstract. Dissolved organic carbon concentrations ([DOC]) in surface waters are increasing in many regions of Europe and North America. These increases are likely driven by a combination of changing climate, recovery from acidification and change in severity of winter storms in coastal areas. INCA-C, a process-based model of climate effects on surface water [DOC], was used to explore the mechanisms by which changing climate controls seasonal to inter-annual patterns of [DOC] in the lake and outflow stream of a small Finnish catchment between 1990 and 2003. Both production in the catchment and mineralization in the lake controlled [DOC] in the lake. Concentrations in the catchment outflow were controlled by rates of DOC production in the surrounding organic soils. The INCA-C simulation results were compared to those obtained using artificial neural networks (ANN). In general, "black box" ANN models provide better fits to observed data but process-based models can identify the mechanism responsible for the observed pattern. A statistically significant increase was observed in both INCA-C modelled and measured annual average [DOC] in the lake. This suggests that some of the observed increase in surface water [DOC] is caused by climate-related processes operating in the lake and catchment. However, a full understanding of surface water [DOC] dynamics can only come from catchment-scale process-based models linking the effects of changing climate and deposition on aquatic and terrestrial environments.

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THE COMPOSITION OF CYCLOPOID ASSEMBLAGES IN ECOLOGICALLY DIFFERENT GROUNDWATER HABITATS OF A DANUBE RIVERINE WETLAND IN AUSTRIA

Crustaceana ◽

10.1163/156854099503780 ◽

1999 ◽

Vol 72 (8) ◽

pp. 883-892 ◽

Cited By ~ 4

Author(s):

Peter Pospisil

Keyword(s):

Species Richness ◽

Surface Water ◽

Low Temperature ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Surface Waters ◽

Groundwater Monitoring ◽

Temperature Fluctuations ◽

Strong Surface ◽

Riverine Wetland

AbstractThe cyclopoid assemblages of three groundwater monitoring sites in the Danube wetlands were investigated from mid 1996 to end 1997. One of these sites, located 200 m from surface waters, represents a stable, oligotrophic habitat (characterized by low temperature fluctuations and low dissolved organic carbon (DOC)-values). Six groundwater cyclopoids permanently inhabit this habitat. At two other sites, located closely to a backwater of the Danube and characterized by strong surface water influences, only four stygobitic cyclopoids occur altogether. These data support modern opinions, which stress that groundwater habitats are more heterogeneous and display higher biodiversity (i. e., higher species richness) of selected crustacean taxocoenoses (in this case, Cyclopoida) than expected earlier. Die Grundwassercyclopiden dreier Untersuchungsstellen in den Donauauen wurden von Juni 1996 bis Dezember 1997 untersucht. Eine dieser Stellen reprasentierte ein stabiles, oligotrophes Habitat (charakterisiert durch geringe Temperaturschwankungen und niedrige ''dissolved organic carbon'' (DOC)-Werte). Dieses Habitat wurde von sechs Grundwassercyclopiden standig besiedelt, im Vergleich zu nur vier Arten an den beiden anderen Stellen zusammen, die durch das nahe Oberflachengewasser stark beeinflusst wurden. Diese Beobachtungen bestatigen die moderne Ansicht, dass im Grundwasser eine grossere Habitatdiversitat sowie eine grossere Biodiversitat (d. h., Artenreichtum) von ausgewahlten Crustaceen-Taxozonosen (in diesem Fall Cyclopoida) zu finden ist als bisher angenommen.

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Is carbonate sediment dissolution a significant source of dissolved organic matter to Florida Bay?

10.5194/egusphere-egu2020-812 ◽

2020 ◽

Author(s):

Mary Zeller ◽

Bryce Van Dam ◽

Chris Lopes ◽

Ashley Smyth ◽

Christopher Osburn ◽

...

Keyword(s):

Organic Matter ◽

Surface Water ◽

Organic Carbon ◽

Surface Waters ◽

Florida Bay ◽

Source Surface ◽

Carbonate Sediments ◽

Seagrass Meadows ◽

Autochthonous Organic Matter ◽

The Impact

Florida Bay is subtropical embayment characterized by dense Thalassia testudinum seagrass meadows, the prevalence of carbonate-rich sediments, and relatively long residence times (~1 yr). Florida Bay seagrass meadows store appreciable quantities of allochthonous and autochthonous organic matter (OM) as so-called &#8216;blue carbon&#8217;, the fate of which is therefore tied to that of the carbonate minerals it is bound to. &#160;Dissolved organic carbon (DOC) concentrations are also relatively high (~7-12 mg/L), despite potential photo-oxidative loss in this shallow and long residence time system, as well as low internal DOC production due to the ecosystem&#8217;s documented oligotrophy.&#160; These carbonate sediments can dissolve through net acid production via sediment heterotrophic processes as well as sulfide oxidation, processes which may be enhanced via O2 pumping through seagrass roots. &#160;This study investigated the impact of carbonate dissolution on the release of sediment-associated OM to surface waters, and the relative contribution of this process to surface water DOC quantity and quality.&#160; We undertook a three-part experimental approach, with analyses including EEMs, &#948;13C-DOC, and FT-ICR-MS, to better understand the sources and fate of DOC in Florida Bay. 1) We conducted a spatial survey of surface waters, pore waters, and acid-leachable (representing the &#8216;carbonate-bound&#8217; OM fraction) sedimentary OM. &#160;2) &#160;We conducted a DOM photodegradation study using two potential source surface waters, from a main tributary (Taylor Slough) and a central mangrove island.&#160; 3) We conducted benthic flux experiments using intact sediment cores facilitating direct measurements of the quality and quantity of DOC release from sediments. The flux information was placed into the context of sediment dissolution rates, estimated from coinciding determinations of alkalinity and inorganic carbon.While analyses are ongoing, our initial results indicate a high degree of similarity between the fluorescence signature (PARAFAC components and fluorescence indices) of acid-leachable sedimentary OM, and that of DOC in pore water and surface water throughout Florida Bay.&#160; Taken together, our study points to sediment dissolution as an important, yet understudied, process affecting organic carbon cycling in carbonate-dominated systems like Florida Bay.

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Aquatic mollusks in North Dakota during the last 12000 years

Canadian Journal of Zoology ◽

10.1139/z76-196 ◽

1976 ◽

Vol 54 (10) ◽

pp. 1688-1693 ◽

Cited By ~ 3

Author(s):

A. M. Cvancara

Keyword(s):

Surface Water ◽

Water Chemistry ◽

North Dakota ◽

Surface Waters ◽

Surface Water Chemistry ◽

Changing Climate ◽

Dissolved Salts

Aquatic mollusks occurred in North Dakota during the last 12 000 years as follows: 12 000–10 000 years ago, 19 species (dated material from 3 sites); 10 000–8000 years ago, 22 species (dated material from 5 sites); 8000–4000 years ago, 11 species (material of inferred age from 2 sites); 4000 years ago to present, 36 species (dated material from 1 site and material of inferred age from 23 sites); and present day, 44 species (material from about 300 stations). The gastropods Valvata sincera (Say), Fossaria decampi (Streng), and Helisoma campanulatum (Say) have not been found in sediments younger than about 9600 years. They may have become regionally extinct about 9000 years ago because of a warmer, drier climate and a corresponding increase of dissolved salts in surface waters. Of two hydrobiid gastropods, Amnicola limosa (Say) has not been found in sediments younger than about 9000 years and has been found at relatively few localities today. Cincinnatia cincinnatiensis (Anthony) has not been found in sediments older than about 2500 years and has been found at many localities today. The occurrence of these two species with time may also be the result of changing climate and surface-water chemistry.

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Multi-year impacts of permafrost disturbance and thermal perturbation on High Arctic stream chemistry

Arctic Science ◽

10.1139/as-2016-0024 ◽

2017 ◽

Vol 3 (2) ◽

pp. 254-276 ◽

Cited By ~ 9

Author(s):

Daniel Lamhonwah ◽

M. J. Lafrenière ◽

S. F. Lamoureux ◽

B. B. Wolfe

Keyword(s):

Surface Water ◽

Water Chemistry ◽

Surface Waters ◽

High Arctic ◽

Thermal Perturbation ◽

Surface Water Chemistry ◽

Near Surface ◽

Ion Concentrations ◽

Soluble Ions ◽

Soil Temperatures

Permafrost disturbances (such as active layer detachment (ALD) slides) and thermal perturbation (deep ground thaw from high soil temperatures) alter Arctic surface water chemistry. However, the potential multi-year impacts on water chemistry and the ultimate recovery time are not well understood. This study evaluates the impacts on surface waters and recovery following disturbance of a High Arctic catchment in 2007 from ALDs. We measured ion concentrations and stable isotopes in surface waters collected between 2006 and 2014 from paired catchments — one disturbed and the other not. The years 2007 and 2012 were exceptionally warm and represent unusual thermal perturbation for both catchments. Results indicate that the exposure and mobilization of soluble ions in near surface soil is a key control over dissolved ion concentrations and composition following ALDs. Runoff in the disturbed catchment shows increased total dissolved solute (TDS) concentrations and seasonal TDS fluxes and changes to the relative composition of individual ions in surface water. These impacts persisted for the 7 year study duration after disturbance and are consistent with the thawing of the solute-rich transient layer and upper permafrost. Thermal perturbation increased TDS concentrations and seasonal fluxes in runoff for up to 2 years, as ions released from ground thaw appear to be available for flushing in subsequent summers.

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Winter-Time Climatic Control on Dissolved Organic Carbon Export and Surface Water Chemistry in an Adirondack Forested Watershed

Environmental Science & Technology ◽

10.1021/es048301m ◽

2005 ◽

Vol 39 (18) ◽

pp. 6993-6998 ◽

Cited By ~ 21

Author(s):

Ji-Hyung Park ◽

Myron J. Mitchell ◽

Charles T. Driscoll

Keyword(s):

Surface Water ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Water Chemistry ◽

Forested Watershed ◽

Carbon Export ◽

Surface Water Chemistry ◽

Climatic Control ◽

Winter Time

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The role of catchment characteristics in determining surface water nitrogen in four upland regions in the UK

Hydrology and Earth System Sciences ◽

10.5194/hess-11-356-2007 ◽

2007 ◽

Vol 11 (1) ◽

pp. 356-371 ◽

Cited By ~ 44

Author(s):

R. C. Helliwell ◽

M. C. Coull ◽

J. J. L. Davies ◽

C. D. Evans ◽

D. Norris ◽

...

Keyword(s):

Surface Water ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Surface Waters ◽

N Deposition ◽

Organic N ◽

Soluble Nitrogen ◽

N Saturation ◽

The South ◽

South Pennines

Abstract. Hydrochemical and catchment data from 80 upland moorland sites in four regions with contrasting climate, soils, geology and geomorphology have been analysed to assess the key catchment attributes that influence enhanced leaching of soluble nitrogen to surface waters. The regions are the South Pennines of northern England, the Snowdonia National Park in north Wales, the Galloway region of south-west Scotland and the Mourne Mountains in Northern Ireland, all highly acidified, with median pH values of <5.5. Linear regression of mean summer and winter concentrations for nitrate (NO3−), ammonium (NH4+), dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) were expressed as functions of catchment attributes. Nitrate concentrations in waters draining catchments dominated by peaty soils (large C pool) were much less than those in catchments dominated by mineral soils (small C pool). Hence, if future N deposition levels are maintained or increase, high-altitude catchments with small carbon pools are potentially more susceptible to NO3− leaching. All N species exhibit seasonality; this is most marked in Galloway and least marked in the South Pennines, which implies that the South Pennines have reached an advanced stage of N saturation. Surface water inorganic N concentrations and the ratio of dissolved organic carbon (DOC) to dissolved organic N (DON) can be related to deposition inputs, although relationships differ throughout the year. If the DOC/DON ratio is indicative of catchment N saturation, levels of N retention are at least partially determined by deposition levels. This study identifies N deposition as a major inter-regional control on the degree of catchment N saturation and on N leaching to surface waters; it stresses the importance of catchment factors in modifying the relationship between N deposition and leaching in acid sensitive UK upland catchments.

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