Latitude and pH driven trends in the molecular composition of DOM across a north south transect along the Yenisei River

Roth, Vanessa-Nina; Dittmar, Thorsten; Gaupp, Reinhard; Gleixner, Gerd

doi:10.1016/j.gca.2013.09.002

Cited by 65 publications

(80 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contrasts in soil and stream chemistry across climate and permafrost gradients have been interpreted as space‐for‐time proxies to predict potential responses of carbon and nitrogen cycles to climate warming, and in particular to thawing permafrost [ Frey et al ., ; Jones et al ., ; Kawahigashi et al ., ; Roth et al ., ]. However, significant variation in the magnitude and direction of these biogeochemical patterns across high‐latitude regions currently limits mechanistic understanding of observed patterns and predictive power of ecosystem models that estimate material fluxes from catchments to coasts.…”

Section: Discussionmentioning

confidence: 98%

“…Thus, thawing at the southern extent of permafrost may contribute to an observed latitudinal decline in NO 3 − concentration from subarctic to arctic streams [ Jones et al ., ]. Despite these general spatial and seasonal patterns linking permafrost‐driven hydrology to mobilization of C and N from catchments, significant variation in concentration or load and composition of DOM and inorganic N occurs across catchments and among regions at high latitudes [ Holmes et al ., ; McClelland et al ., ; Roth et al ., ; Tank et al ., ; Walker et al ., ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Catchment influence on nitrate and dissolved organic matter in Alaskan streams across a latitudinal gradient

et al. 2016

View full text Add to dashboard Cite

Spatial patterns in carbon (C) and nitrogen (N) cycles of high‐latitude catchments have been linked to climate and permafrost and used to infer potential changes in biogeochemical cycles under climate warming. However, inconsistent spatial patterns across regions indicate that factors in addition to permafrost and regional climate may shape responses of C and N cycles to climate change. We hypothesized that physical attributes of catchments modify responses of C and N cycles to climate and permafrost. We measured dissolved organic C (DOC) and nitrate (NO3−) concentrations, and composition of dissolved organic matter (DOM) in 21 streams spanning boreal to arctic Alaska, and assessed permafrost, topography, and attributes of soils and vegetation as predictors of stream chemistry. Multiple regression analyses indicated that catchment slope is a primary driver, with lower DOC and higher NO3− concentration in streams draining steeper catchments, respectively. Depth of the active layer explained additional variation in concentration of DOC and NO3−. Vegetation type explained regional variation in concentration and composition of DOM, which was characterized by optical methods. Composition of DOM was further correlated with attributes of soils, including moisture, temperature, and thickness of the organic layer. Regional patterns of DOC and NO3− concentrations in boreal to arctic Alaska were driven primarily by catchment topography and modified by permafrost, whereas composition of DOM was driven by attributes of soils and vegetation, suggesting that predicting changes to C and N cycling from permafrost‐influenced regions should consider catchment setting in addition to dynamics of climate and permafrost.

show abstract

Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Catchment influence on nitrate and dissolved organic matter in Alaskan streams across a latitudinal gradient

et al. 2016

View full text Add to dashboard Cite

show abstract

“…6 et al, 2014), freshwater (Kujawinski, 2002;Kim et al, 2003, Roth et al, 2013Ward et al, 2013) and sediment pore water systems (Schmidt et al, 2009;Seidel et al, 2014). …”

Section: Accepted Manuscriptmentioning

confidence: 99%

Bioavailability and molecular composition of dissolved organic matter from a diffuse hydrothermal system

et al. 2015

Self Cite

View full text Add to dashboard Cite

Please cite this article as: Rossel, Pamela E., Stubbins, Aron, Hach, Philipp F., Dittmar, Thorsten, Bioavailability and molecular composition of dissolved organic matter from a diffuse hydrothermal system, Marine Chemistry (2015), AbstractFluids from the diffusive hydrothermal vent Woody located at the Menez Gwen hydrothermal field were collected directly from a fissure using a Kiel pumping system (KIPs). The fluids were incubated in a biodegradation experiment with the resident microbial community at in situ temperature (55°C). In addition to the initial fluid (T 0 ), sub-samples were collected at three time points: 12.5 h (T 1 ), 38 h (T 2 ) and 180 h (T final ). Whole water samples were characterized by spectrophotometry and for dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations. Solid-phase extracted dissolved organic matter (SPE-DOM) was molecularly characterized using a 15 Tesla Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR-MS). Based on Mg 2+ concentrations, vent fluids were diluted ca. 1:99% with seawater. SPE-DOC concentrations remained constantly low (30 µM) over the course of incubation, while DOC and TDN (1180 µM and 16 µM, respectively, at T 0 ) decreased sharply (to 80 µM and 9 µM, respectively, at T final ). This biolabile DOC is likely composed of volatiles and short-chain hydrocarbons, and the reason behind their extraordinarily high concentration remains unknown. Molecular characterization of SPE-DOM in fluids and seawater identified over 3000 molecular formulae, which were separated into different groups according to their reactivity. The half-lifes of the more reactive groups ranged between 6-7 h, 18-21 h and 5-106 days, and represented 7.3, 2.0 and 7.5% of the total formulae present in T 0 , while the majority (83%) did not exhibit any significant trend during the experiment. Despite the small molecular changes in SPE-DOM, a decrease in the number of formulae and average molecular mass was observed, the latter consistent with an increase in the spectral slope over the wavelength range 275-295 nm (S 275-295 ) during the A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 3 experiment. An increase in aromatic molecular formulae during the incubation was also corroborated by a concurrent increase in the absorption coefficient at 254 nm normalized to DOC concentrations (SUVA 254 ), an optical indicator of aromatic content. Thus both FT-ICR-MS and optical properties over the course of the incubation corroborated a decrease in molecular mass and increase in aromaticity. This study is the first to report the optical and molecular transformations of bio-labile DOM from diffusive hydrothermal systems.

show abstract

“…Previous studies demonstrated that the application of statistical tools simplifies data interpretation Kujawinski et al 2009;Sleighter et al 2010). Recent FT-ICR MS studies on Arctic DOM observed latitude and pH driven trends in the molecular composition of DOM in the Yenisey River (Roth et al 2013). The authors showed that the climatic gradients along the latitude (from south to north) were related to a higher abundance of low molecular weight components, nitrogen-containing components and an increase in the degree of unsaturation of riverine DOM.…”

Section: Introductionmentioning

confidence: 99%

Origin-specific molecular signatures of dissolved organic matter in the Lena Delta

et al. 2014

View full text Add to dashboard Cite

Large Arctic rivers discharge significant amounts of dissolved organic matter (DOM) into the Arctic Ocean. We sampled natural waters of the Lena River, the Buor-Khaya Bay (Laptev Sea), permafrost melt water creeks, ice complex melt water creeks and a lake. The goal of this study was to characterize the molecular DOM composition with respect to different water bodies within the Lena Delta. We aimed at an identification of source-specific DOM molecular markers and their relative contribution to DOM of different origin. The molecular characterization was performed for solid-phase extracted DOM by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Average dissolved organic carbon concentrations in the original samples were 490 ± 75 lmol C L-1 for riverine and bay samples and 399 ± 115 lmol C L-1 for permafrost melt water creeks. Average TDN concentrations were elevated in the permafrost melt waters (19.7 ± 7.1 lmol N L-1) in comparison to the river and the bay (both 13.2 ± 2.6 lmol N L-1). FT-ICR MS and statistical tools demonstrated that the origin of DOM in the Lena Delta was systematically reflected in its molecular composition. Magnitude weighted parameters calculated from MS data water creeks in comparison to 1.281 for river and 1.230 for the bay samples. In the bay samples we observed a higher fraction of oxygen-rich components which was reflected in an O/C wa ratio of 0.445 in comparison to 0.425 and 0.427 in the river and creeks, respectively. From the southernmost location to the bay a relative depletion of nitrogenous molecular markers and an enrichment of oxidized DOM components occurred. The highest contribution of nitrogenous components was indicative for creeks reflected in a C/N wa of 104 in comparison to 143 and 176 in the river and bay, respectively. These observations were studied on a molecular formula level using principal component and indicator value analyses. The results showed systematic differences with respect to water origin and constitute an important basis for a better mechanistic understanding of DOM transformations in the changing Arctic rivers.

show abstract

Latitude and pH driven trends in the molecular composition of DOM across a north south transect along the Yenisei River

Cited by 65 publications

References 60 publications

Catchment influence on nitrate and dissolved organic matter in Alaskan streams across a latitudinal gradient

Catchment influence on nitrate and dissolved organic matter in Alaskan streams across a latitudinal gradient

Bioavailability and molecular composition of dissolved organic matter from a diffuse hydrothermal system

Origin-specific molecular signatures of dissolved organic matter in the Lena Delta

Contact Info

Product

Resources

About