Effect of Acid Deposition on Quantity and Quality of Dissolved Organic Matter in Soil–Water

Ekström, Sara; Kritzberg, Emma S.; Kleja, Dan Berggren; Larsson, Niklas; Nilsson, P. Anders; Granéli, Wilhelm; Bergkvist, Bo

doi:10.1021/es104126f

Cited by 88 publications

(89 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One obvious explanation for accelerated a 420 increases is an increased soil export of colored dissolved organic matter. Increased soil export of colored dissolved organic matter has previously been related to decreasing sulfate deposition (Ekström et al 2011;Evans et al 2012;Monteith et al 2007;Tipping and Hurley 1988). On a spatial scale we found no evidence that SO 4 -S concentrations have an influence on a 420 variation, probably because of an overriding effect of land-cover.…”

Section: Discussionmentioning

confidence: 98%

Sensitivity of freshwaters to browning in response to future climate change

et al. 2015

View full text Add to dashboard Cite

Many boreal waters are currently becoming browner with effects on biodiversity, fish production, biogeochemical processes and drinking water quality. The question arises whether and at which speed this browning will continue under future climate change. To answer the question we predicted the absorbance (a 420 ) in 6347 lakes and streams of the boreal region under future climate change. For the prediction we modified a numerical model for a 420 spatial variation which we tested on a temporal scale by simulating a 420 inter-annual variation in 48 out of the 6347 Swedish waters. We observed that inter-annual a 420 variation is strongly driven by precipitation that controls the water flushing through the landscape. Using the predicted worst case climate scenario for Sweden until 2030, i.e., a 32 % precipitation increase, and assuming a 10 % increase in imports of colored substances into headwaters but no change in land-cover, we predict that a 420 in the 6347 lakes and streams will, in the worst case, increase by factors between 1.1 and 7.6 with a median of 1.3. This increase implies that a 420 will rise from the present 0.1-86 m −1 (median: 7.3 m ), which can cause problems for the preparation of drinking water in a variety of waters. Our model approach clearly demonstrates that a homogenous precipitation increase results in very heterogeneous a 420 changes, where lakes with a long-term mean landscape water retention time between 1 and 3 years are particularly vulnerable to climate change induced browning. Since these lake types are quite often used as drinking water resources, preparedness is needed for such waters.

show abstract

Section: Discussionmentioning

confidence: 98%

Sensitivity of freshwaters to browning in response to future climate change

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The south of Sweden has been more severely affected by sulfur deposition. As reversed acidification has been suggested to be an important factor behind changes in OM quantity (Monteith et al, 2007;Erlandsson et al, 2008) and quality (Ekström et al, 2011), this phenomenon may be more important in the southern part of Sweden, and this may be reflected in the strongly upward trends in the south and few and smaller trends in the north.…”

Section: The Role Of Fe To Water Colormentioning

confidence: 99%

“…Unfortunately, measures of OM quality are rarely included in environmental monitoring or experiments addressing brownification (but see Freeman et al, 2001;Ekström et al, 2011). By contrast, there is a wealth of studies reporting correlations between Fe and water color (Canfield et al, 1984;Pennanen and Frisk, 1984;Heikkinen and Ihme, 1995;Maloney et al, 2005).…”

Section: E S Kritzberg and S M Ekström: Increasing Iron Concentramentioning

confidence: 99%

“…The carbon specific absorbance (Abs 420 /TOC) can vary depending on the molecular structure of the organic matter. For example, when comparing DOM in soil water from plots exposed to high versus low acid irrigation, the former had lower carbon specific absorbance, corresponding to lower molecular weight and aromaticity (Ekström et al, 2011). Thus, coupled with an increase in DOM in soil water as a result of lower acidification, there was a change in DOM quality.…”

Section: The Role Of Organic Matter To Water Colormentioning

confidence: 99%

See 1 more Smart Citation

Increasing iron concentrations in surface waters – a factor behind brownification?

2012

View full text Add to dashboard Cite

Abstract. Browning of inland waters has been noted over large parts of the Northern hemisphere and is a phenomenon with both ecological and societal consequences. The increase in water color is generally ascribed to increasing concentrations of dissolved organic matter of terrestrial origin. However, oftentimes the increase in water color is larger than that of organic matter, implying that changes in the concentration of organic matter alone cannot explain the enhanced water color. Water color is known to be affected also by the quality of organic matter and the prevalence of iron. Here we investigated trends in water color, organic matter and iron between 1972 and 2010 in 30 rivers draining into the Swedish coast (data from the national Swedish monitoring program), and performed a laboratory iron addition experiment to natural waters, to evaluate the role of iron and organic matter in determining water color. By comparing the effect of iron additions on water color in the experiment, to variation in water color and iron concentration in the monitoring data, we show that iron can explain a significant share of the variation in water color (on average 25 %), especially in the rivers in the north of Sweden (up to 74 %). Furthermore, positive trends for iron are seen in 27 of 30 rivers (21-468 %) and the increase in iron is larger than that of organic matter, indicating that iron and organic matter concentrations are controlled by similar but not identical processes. We speculate that increasing iron concentrations can be caused by changes in redox conditions, that mean that more anoxic water with high concentrations of soluble FeII are feeding into the surface waters. More studies are needed about why iron is increasing so strongly, since both causes and consequences are partly different from those of increasing organic matter content.

show abstract

“…A number of climate-sensitive mechanisms have been suggested to cause an increase in OC export from the terrestrial to the aquatic environment; for example, increased temperatures enhance decomposition rates in organic-rich soils (10) and promote vegetation cover (11). Changes in the amount and timing of precipitation potentially lead to alterations of hydrological flow paths and intensities, controlling OC leaching from soils (12)(13)(14).…”

mentioning

confidence: 99%

Early land use and centennial scale changes in lake-water organic carbon prior to contemporary monitoring

Meyer-Jacob

Tolu

Bigler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Organic carbon concentrations have increased in surface waters across parts of Europe and North America during the past decades, but the main drivers causing this phenomenon are still debated. A lack of observations beyond the last few decades inhibits a better mechanistic understanding of this process and thus a reliable prediction of future changes. Here we present past lake-water organic carbon trends inferred from sediment records across central Sweden that allow us to assess the observed increase on a centennial to millennial time scale. Our data show the recent increase in lake-water carbon but also that this increase was preceded by a landscape-wide, long-term decrease beginning already A.D. 1450-1600. Geochemical and biological proxies reveal that these dynamics coincided with an intensification of human catchment disturbance that decreased over the past century. Catchment disturbance was driven by the expansion and later cessation of widespread summer forest grazing and farming across central Scandinavia. Our findings demonstrate that early land use strongly affected past organic carbon dynamics and suggest that the influence of historical landscape utilization on contemporary changes in lake-water carbon levels has thus far been underestimated. We propose that past changes in land use are also a strong contributing factor in ongoing organic carbon trends in other regions that underwent similar comprehensive changes due to early cultivation and grazing over centuries to millennia.lake-water quality | carbon cycling | land use | Holocene | paleoecology O ver the past three decades, monitoring programs have recorded a widespread increase of organic carbon (OC) concentrations in surface waters in parts of Europe and North America (1-4). OC in lakes and rivers plays a major role in the global carbon cycle by transporting carbon from terrestrial to freshwater and marine environments (5), determining drinking water quality and associated treatment costs (6), and affecting aquatic ecosystem functioning. In aquatic ecosystems, OC influences energy mobilization, light conditions (7), water acidity (8), as well as the transport of metals and pollutants (9). The widespread occurrence of this increase in surface water OC, also referred to as browning or brownification due to an associated increase in color, suggests that regional rather than local factors are the drivers behind this phenomenon, but at present the underlying mechanisms are still controversial.Several hypotheses have been proposed to explain this recent OC increase, from climate change to changes in anthropogenic forcing such as declining atmospheric acid deposition or alterations in landscape utilization. A number of climate-sensitive mechanisms have been suggested to cause an increase in OC export from the terrestrial to the aquatic environment; for example, increased temperatures enhance decomposition rates in organic-rich soils (10) and promote vegetation cover (11). Changes in the amount and timing of precipitation potentially lead to alteration...

show abstract

Effect of Acid Deposition on Quantity and Quality of Dissolved Organic Matter in Soil–Water

Cited by 88 publications

References 37 publications

Sensitivity of freshwaters to browning in response to future climate change

Sensitivity of freshwaters to browning in response to future climate change

Increasing iron concentrations in surface waters – a factor behind brownification?

Early land use and centennial scale changes in lake-water organic carbon prior to contemporary monitoring

Contact Info

Product

Resources

About