Variation in dissolved organic matter (DOM) stoichiometry in U.K. freshwaters: Assessing the influence of land cover and soil C:N ratio on DOM composition

Dissolved organic matter (DOM) plays an important role in freshwater biogeochemistry. To investigate the influence of catchment character on the quality and quantity of DOM in freshwaters, 45 sampling sites draining subcatchments of contrasting soil type, hydrology, and land cover within one large upland‐dominated and one large lowland‐dominated catchment were sampled over a 1‐yr period. Dominant land cover in each subcatchment included: arable and horticultural, blanket peatland, coniferous woodland, and improved, unimproved, acid, and calcareous grasslands. The composition of the C, N, and P pool was determined as a function of the inorganic nutrient species (NO3−, NO2−, NH4+, and PO43−) and dissolved organic nutrient (dissolved organic carbon [DOC], dissolved organic nitrogen [DON], and dissolved organic phosphorus [DOP]) concentrations. DOM quality was assessed by calculation of the molar DOC : DON and DOC : DOP ratios and specific ultraviolet absorbance (SUVA254). In catchments with little anthropogenic nutrient inputs, DON and DOP typically composed > 80% of the total dissolved nitrogen (TDN) and total dissolved phosphorus (TDP) concentrations. By contrast, in heavily impacted agricultural catchments DON and DOP typically comprised 5–15% of TDN and 10–25% of TDP concentrations. Significant differences in DOC : DON and DOC : DOP ratios were observed between land cover class with significant correlations observed between both the DOC : DON and DOC : DOP molar ratios and SUVA254 (rs = 0.88 and 0.84, respectively). Analysis also demonstrated a significant correlation between soil C : N ratio and instream DOC : DON/DOP (rs = 0.79 and 0.71, respectively). We infer from this that soil properties, specifically the C : N ratio of the soil organic matter pool, has a significant influence on the composition of DOM in streams draining through these landscapes.

[1]  P. Johnes,et al.  Characterisation of treated effluent from four commonly employed wastewater treatment facilities: A UK case study. , 2019, Journal of environmental management.

[2]  E. Khan,et al.  Bioavailability of dissolved organic nitrogen (DON) in wastewaters from animal feedlots and storage lagoons. , 2017, Chemosphere.

[3]  A. Borges,et al.  Effects of human land use on the terrestrial and aquatic sources of fluvial organic matter in a temperate river basin (The Meuse River, Belgium) , 2017, Biogeochemistry.

[4]  M. Futter,et al.  Variability in organic carbon reactivity across lake residence time and trophic gradients , 2017 .

[5]  R. Moorhead,et al.  Influence of land use and land cover on the spatial variability of dissolved organic matter in multiple aquatic environments , 2017, Environmental Science and Pollution Research.

[6]  H. Biester,et al.  Changes in dissolved organic matter quality in a peatland and forest headwater stream as a function of seasonality and hydrologic conditions , 2017 .

[7]  P. Johnes,et al.  Assessing the drivers of dissolved organic matter export from two contrasting lowland catchments, U.K. , 2016, The Science of the total environment.

[8]  S. Launiainen,et al.  Predicting the export and concentrations of organic carbon, nitrogen and phosphorus in boreal lakes by catchment characteristics and land use: A practical approach , 2016, Ambio.

[9]  M. Xenopoulos,et al.  Human activities cause distinct dissolved organic matter composition across freshwater ecosystems , 2016, Global change biology.

[10]  B. Kronvang,et al.  Global effects of agriculture on fluvial dissolved organic matter , 2015, Scientific Reports.

[11]  H. Laudon,et al.  The relative influence of land cover, hydrology, and in‐stream processing on the composition of dissolved organic matter in boreal streams , 2015 .

[12]  P. Giorgio,et al.  Distinct patterns of microbial metabolism associated to riverine dissolved organic carbon of different source and quality , 2015 .

[13]  D. Sedlak,et al.  Bioavailability and characterization of dissolved organic nitrogen and dissolved organic phosphorus in wastewater effluents. , 2015, The Science of the total environment.

[14]  D. Zak,et al.  Comparison of organic matter composition in agricultural versus forest affected headwaters with special emphasis on organic nitrogen. , 2015, Environmental science & technology.

[15]  M. Palmer,et al.  Dissolved organic matter quality and bioavailability changes across an urbanization gradient in headwater streams. , 2014, Environmental science & technology.

[16]  Philip Jordan,et al.  Do septic tank systems pose a hidden threat to water quality , 2014 .

[17]  C. Stedmon,et al.  Bioavailability of riverine dissolved organic matter in three Baltic Sea estuaries and the effect of catchment land use , 2013 .

[18]  A. MacKay,et al.  Similarities in effluent organic matter characteristics from Connecticut wastewater treatment plants. , 2012, Water research.

[19]  P. Mulholland,et al.  Distinguishing dynamics of dissolved organic matter components in a forested stream using kinetic enrichments , 2012 .

[20]  J. Fuhrer,et al.  Control of soil pH on turnover of belowground organic matter in subalpine grassland , 2013, Biogeochemistry.

[21]  Delphis F. Levia,et al.  Dissolved organic matter (DOM) concentration and quality in a forested mid-Atlantic watershed, USA , 2012, Biogeochemistry.

[22]  A. Butturini,et al.  Nitrogen processes in aquatic ecosystems , 2011 .

[23]  H. Jarvie,et al.  Quantifying the impact of septic tank systems on eutrophication risk in rural headwaters. , 2011, Environment international.

[24]  Heileen Hsu-Kim,et al.  Influence of dissolved organic matter on the environmental fate of metals, nanoparticles, and colloids. , 2011, Environmental science & technology.

[25]  P. Naden,et al.  Effects of storm events on mobilisation and in-stream processing of dissolved organic matter (DOM) in a Welsh peatland catchment , 2010 .

[26]  J. Aitkenhead-Peterson,et al.  Dissolved organic carbon and nitrogen in urban and rural watersheds of south-central Texas: land use and land management influences , 2009 .

[27]  P. Conan,et al.  Export of dissolved organic matter in relation to land use along a European climatic gradient. , 2009, The Science of the total environment.

[28]  Pauline F. Grierson,et al.  Bioavailability and composition of dissolved organic carbon and nitrogen in a near coastal catchment of south-western Australia , 2009 .

[29]  R. Spencer,et al.  The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed , 2008 .

[30]  K. Pagilla,et al.  Bioavailability of Dissolved Organic Nitrogen in Treated Effluents , 2008, Water environment research : a research publication of the Water Environment Federation.

[31]  P. Mulholland,et al.  In‐stream biotic control on nutrient biogeochemistry in a forested stream, West Fork of Walker Branch , 2007 .

[32]  J. Sickman,et al.  Effects of Urbanization on Organic Carbon Loads in the Sacramento River, California , 2007 .

[33]  R. Ganeshram,et al.  Discriminatory classification of natural and anthropogenic waters in two U.K. estuaries. , 2007, The Science of the total environment.

[34]  S. Seitzinger,et al.  Bioavailability of dissolved organic nitrogen and carbon from nine rivers in the eastern United States , 2006 .

[35]  P. Kortelainen,et al.  Export of DOM from Boreal Catchments: Impacts of Land Use Cover and Climate , 2005 .

[36]  B. Bergamaschi,et al.  Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon. , 2003, Environmental science & technology.

[37]  L. Hedin,et al.  Nitrogen loss from unpolluted South American forests mainly via dissolved organic compounds , 2002, Nature.

[38]  G. Cauwet.  DOM in the Coastal Zone , 2002 .

[39]  L. Hedin,et al.  addendum: Nitrogen loss from unpolluted South American forests mainly via dissolved organic compounds , 2002, Nature.

[40]  M. Bothwell,et al.  Attenuation of solar ultraviolet radiation by dissolved organic matter alters benthic colonization patterns in streams , 2001, Journal of the North American Benthological Society.

[41]  W. McDowell,et al.  Dissolved organic nitrogen budgets for upland, forested ecosystems in New England , 2000 .

[42]  William H. McDowell,et al.  Soil C:N ratio as a predictor of annual riverine DOC flux at local and global scales , 2000 .

[43]  T. H. Christensen,et al.  Effect of dissolved organic carbon on the mobility of cadmium, nickel and zinc in leachate polluted groundwater , 1996 .

[44]  L. Tranvik,et al.  Enhanced bacterial growth in response to photochemical transformation of dissolved organic matter , 1995 .

[45]  N. Kroer.  Bacterial growth efficiency on natural dissolved organic matter , 1993 .

[46]  P. Johnes,et al.  A procedure for the simultaneous determination of total nitrogen and total phosphorus in freshwater samples using persulphate microwave digestion , 1992 .

[47]  P. Johnes,et al.  Water quality trends in the Windrush catchment: Nitrogen speciation and sediment interactions , 1991 .

[48]  W. McDowell,et al.  Origin, Composition, and Flux of Dissolved Organic Carbon in the Hubbard Brook Valley , 1988 .