Long-term trends in catchment export and lake retention of dissolved organic carbon, dissolved organic nitrogen, total iron, and total phosphorus: The Dorset, Ontario, study, 1978–1998

2005 ◽  
Vol 110 (G1) ◽  
Author(s):  
Peter J. Dillon
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Total Phosphorus ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Total Iron ◽  
Long Term Trends

scholarly journals Net accumulation and flux of dissolved organic carbon and dissolved organic nitrogen in marine plankton communities

2000 ◽  
Vol 45 (5) ◽  
pp. 1097-1111 ◽  
Author(s):  
Morten Søndergaard ◽  
Peter J. le B. Williams ◽  
Gustave Cauwet ◽  
Bo Riemann ◽  
Carol Robinson ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Marine Plankton ◽  
Plankton Communities

Dissolved organic carbon and dissolved organic nitrogen concentrations and exports upstream and downstream of the Dallas–Fort Worth metropolis, Texas, USA

2016 ◽  
Vol 67 (9) ◽  
pp. 1326 ◽  
Author(s):  
J. A. Aitkenhead-Peterson ◽  
M. K. Steele
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Significant Relationship ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Urban Land Use ◽  
Fort Worth ◽  
Sewage Discharge ◽  
Effluent Discharge

Concentrations and export of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) from terrestrial landscapes to near-coastal zones vary with land use. Information on (DOC) and (DON) concentrations and exports from urban ecosystems is sparse; thus, their source from within urbanised watersheds such as soil or vegetation or from permitted sewage discharge is unknown. We examined DOC and DON concentrations and exports in four gauged subwatersheds in the humid subtropical, upper Trinity River basin, upstream and downstream of the Dallas–Fort Worth metropolis in Texas, USA. Annual average DOC concentrations ranged from 5.7±0.4 to 6.4±0.8mgL–1 and DON concentrations ranged from 0.31±0.05 to 0.33±0.14mgL–1. Dissolved organic carbon exports, which included permitted sewage discharge, ranged from 522kgkm–2 year–1 above Dallas–Fort Worth to 3637kgkm–2 year–1 below Dallas–Fort Worth. Permitted effluent discharge contributed between 1 and 35% of DOC loading above and below the Dallas–Fort Worth metropolis. DON exports ranged from 27 to 179kgkm–2 year–1 above and below Dallas–Fort Worth respectively. There was difficulty apportioning permitted effluent-discharge contribution to DON because of the transformations among nitrogen-species. A moderate but significant relationship was found between DOC and sodium concentrations (R2=0.45; P<0.0001; n=40) and between DOC and potassium concentrations (R2=0.45; P<0.0001; n=40). Dissolved organic nitrogen also displayed a significant relationship with sodium (R2=0.33; P<0.001; n=40) and potassium (R2=0.59; P<0.001; n=40), suggesting that increases in these cations to aquatic ecosystems may induce increases in DOC and DON concentrations. Although DOC export was significantly correlated with medium-density urban land use (r=0.96; P<0.05: n=4), DON export was not (r=0.93; P>0.05; n=4), suggesting that land-management practices and permitted point-source discharges have a significant effect on aquatic DOC and DON concentrations and exports derived from urban watersheds.

scholarly journals The importance of riparian zones on stream carbon and nitrogen export in a temperate, agricultural dominated landscape

2012 ◽  
Vol 9 (6) ◽  
pp. 7465-7497 ◽  
Author(s):  
T. Wohlfart ◽  
J.-F. Exbrayat ◽  
K. Schelde ◽  
B. Christen ◽  
T. Dalgaard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Agricultural Land ◽  
Stream Water ◽  
Soil Types ◽  
Organic Soils ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen

Abstract. The surrounding landscape of a stream has crucial impacts on the aquatic environment. This study pictures the hydro-biogeochemical situation of the Tyrebaekken creek catchment in central Jutland, Denmark. The intensively managed agricultural landscape is dominated by rotational croplands. One northern and one southern stream run through the catchment before converging to form a second order brook. The small catchments mainly consist of sandy soil types besides organic soils along the riparian zone of the streams. The aim of the study was to characterise the relative influence of soil type and land use on stream water quality. Nine snapshot sampling campaigns were undertaken during the growing season of 2009. On each sampling day, 20 points along the stream were sampled as well as eight drain outlets and two groundwater wells. Total dissolved nitrogen, nitrate, ammonium nitrogen and dissolved organic carbon (DOC) concentrations were measured and dissolved organic nitrogen (DON) was calculated for each grabbed sample. Electro-conductivity, pH and flow velocity were measured during sampling. Statistical analyses showed significant differences between the northern, southern and converged stream parts, especially for nitrate concentrations with average values of 9.6 mg N l−1, 1.4 mg N l−1 and 3.0 mg N l−1, respectively. Furthermore, throughout the sampling period DON concentrations increased from 0.1 mg N l−1 to 2.8 mg N l−1 and from 0.1 mg N l−1 to 0.8 mg N l−1in the northern and southern streams, respectively. This corresponded to a contribution of up to 81% to total dissolved nitrogen. Multiple-linear regression analyses performed between chemical data and landscape charateristics showed a significant negative influence of organic soils on instream N concentrations and corresponding losses in spite of their overall minor share of the agricultural land (12.9%). On the other hand, organic soil frequency was positively correlated to the corresponding dissolved organic carbon concentrations. Croplands also had a significant influence but with weaker correlations. For our case study we conclude that soil types and corresponding biogeochemical properties have a major influence on stream water chemistry. Meanwhile, the contribution of dissolved organic nitrogen to the total nitrogen budget was substantial in this agricultural dominated landscape.

scholarly journals Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

2016 ◽  
Author(s):  
M. Camino-Serrano ◽  
E. Graf Pannatier ◽  
S. Vicca ◽  
S. Luyssaert ◽  
M. Jonard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Atmospheric Deposition ◽  
Soil Solution ◽  
Surface Waters ◽  
European Forests ◽  
Icp Forests ◽  
Level Ii ◽  
Long Term Trends

Abstract. Dissolved organic carbon (DOC) in soil solution is connected to DOC in surface waters through hydrological flows. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site-studies has failed so far to establish consistent trends in soil solution DOC, whereas increasing concentrations in European surface waters over the past decades appear to be the norm, possibly as a result from acidification recovery. The objectives of this study were therefore to understand the long-term trends of soil solution DOC from a large number of European forests (ICP Forests Level II plots) and determine their main physico-chemical and biological controls. We applied trend analys is at two levels: 1) to the entire European dataset and 2) to the individual time series and related trends with plot characteristics, i.e., soil and vegetation properties, soil solution chemistry and atmospheric deposition loads. Analyses of the entire dataset showed an overall increasing trend in DOC concentrations in the organic layers, but, at individual plots and depths, there was no clear overall trend in soil solution DOC across Europe with temporal slopes of soil solution DOC ranging between −16.8 % yr−1 and +23 % yr−1 (median= +0.4 % yr−1). The non-significant trends (40 %) outnumbered the increasing (35 %) and decreasing trends (25 %) across the 97 ICP Forests Level II sites. By means of multivariate statistics, we found increasing DOC concentrations with increasing mean nitrate (NO3−) deposition and decreasing DOC concentrations with decreasing me an sulphate (SO42−) deposition, with the magnitude of these relationships depending on plot deposition history. While the attribution of increasing trends in DOC to the reduct ion of SO42− deposition could be confirmed in N-poorer forests, in agreement with observations in surface waters, this was not the case in N-richer forests. In conclusion, long-term trends of soil solution DOC reflected the interactions between controls acting at local (soil and vegetation properties) and regional (atmospheric deposition of SO42− and inorganic N) scales.

A meszezés hatása a homoktalaj oldható szerves-szén- és szerves-nitrogén-tartalmára tenyészedény-kísérletben

2002 ◽  
Vol 51 (3-4) ◽  
pp. 341-350 ◽  
Author(s):  
Tibor Filep ◽  
Péter Tamás Nagy ◽  
Sándorné Kincses
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Avena Sativa ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
List Type

Egy homok textúrájú barna erdőtalajjal beállított tenyészedény-kísérletben kétféle meszező anyag (mészkő és dolomit) hatását vizsgáltuk a talaj vízoldható szerves-C-(dissolved organic carbon, DOC) és szerves-N-(dissolved organic nitrogen, DON) tartalmára, zab (Avena sativa L.) jelzőnövény alkalmazásával. A tenyészidő alatt három alkalommal (a 6., 10. és a 15. héten) vettünk talajmintát. A kísérlet eredményei alapján az alábbi megállapításokat tehetjük: A DOC mennyisége statisztikailag igazolható módon növekedett a mészadagok növekedésével mindhárom mintavételi időpontban. Ennek oka a pH emelkedése, ill. a mikrobiális aktivitás fokozódása. A talaj pH-ja és a DOC közötti összefüggés legjobban az y = 0,3733e0,7893x, r = 0,903*** egyenlettel írható le.A DON esetében csak az 1. mintavételnél találtunk szignifikáns mészhatást, a tenyészidő további részében statisztikailag igazolhatóan nem növekedtek a DON-koncentrációk a mészadagokkal.Vizsgálataink arra utalnak, hogy a DOC és a DON biodegradációja eltérő sebességű az adott kísérlet körülményei között.A talaj vízoldható szerves-C-tartalma a 15 hetes tenyészidő alatt szignifikánsan nem változott, míg a DON-koncentráció szignifikáns csökkenést mutatott.A mészkőpor alkalmazásakor magasabb DOC-, ill. DON-koncentrációkat mértünk, mint a dolomitkezeléseknél, de ez statisztikailag nem volt igazolható.

scholarly journals Long Term Trends and Dynamics of Dissolved Organic Carbon (DOC) in a Subtropical Reservoir Basin

Water ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 545 ◽  
Author(s):  
Ming Chow ◽  
Chao-Chen Lai ◽  
Hsiang-Yi Kuo ◽  
Chih-Hsien Lin ◽  
Tzong-Yueh Chen ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Long Term Trends ◽  
Reservoir Basin
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