Biodegradability of natural dissolved organic matter collected from a UK moorland stream

Stutter, Marc; Richards, Samia; Dawson, Julian James Charles

doi:10.1016/j.watres.2012.11.035

Cited by 53 publications

(45 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Novel molecules are synthesized by soil microbes, and some of these metabolites enter the DOM reservoir in groundwater of systems (Chapelle et al 2009(Chapelle et al , 2011. In comparison, substantially higher percentages of BDOC were measured in surface water (29 ± 1 %; this study), which is consistent when compared to average literature values for streams (11-27 %), lakes (14 %), rivers (19 %), and seawater (19 %) (Qualls and Haines 1992;Søndergaard and Middelboe 1995;Volk et al 1997;Stutter et al 2013). The percentages of BDOC reported in coastal estuaries were quite variable (8-29 %) but mostly higher than those in groundwater (Moran and Hodson 1999;Raymond and Bauer 2000;Lønborg and Søndergaard 2009).…”

Section: Dom Bioavailability In Groundwatersupporting

confidence: 88%

Origins and bioavailability of dissolved organic matter in groundwater

et al. 2014

View full text Add to dashboard Cite

Dissolved organic matter (DOM) in groundwater influences water quality and fuels microbial metabolism, but its origins, bioavailability and chemical composition are poorly understood. The origins and concentrations of dissolved organic carbon (DOC) and bioavailable DOM were monitored during a long-term (2-year) study of groundwater in a fractured-rock aquifer in the Carolina slate belt. Surface precipitation was significantly correlated with groundwater concentrations of DOC, bioavailable DOM and chromophoric DOM, indicating strong hydrological connections between surface and ground waters. The physicochemical and biological processes shaping the concentrations and compositions of DOM during its passage through the soil column to the saturated zone are conceptualized in the regional chromatography model. The model provides a framework for linking hydrology with the processes affecting the transformation, remineralization and microbial production of DOM during passage through the soil column. Lignin-derived phenols were relatively depleted in groundwater DOM indicating substantial removal in the unsaturated zone, and optical properties of chromophoric DOM indicated lower molecular weight DOM in groundwater relative to surface water. The prevalence of glycine, caminobutyric acid, and D-enantiomers of amino acids indicated the DOM was highly diagenetically altered. Bioassay experiments were used to establish DOCnormalized yields of amino acids as molecular indicators of DOM bioavailability in groundwater. A relatively small fraction (8 ± 4 %) of DOC in groundwater was bioavailable. The relatively high yields of specific D-enantiomers of amino acids indicated a substantial fraction (15-34 %) of groundwater DOC was of bacterial origin.

show abstract

Section: Dom Bioavailability In Groundwatersupporting

confidence: 88%

Origins and bioavailability of dissolved organic matter in groundwater

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Despite this, we did not find evidence for widespread consistent and rapid in-stream and estuarine processing of fluvial C. C losses were confined to a few biogeochemical 'hot spots' in the lower reaches of the catchment and sporadic elsewhere, yet where they occurred the losses were on occasion very high, up to 44 % for DOC loss downstream of confluences and approximately 30 % DOC loss during estuarinefreshwater mixing. These results provide evidence that peat-derived fluvial C may be highly reactive, and that rapid physico-chemical processes may at times cause losses that are significantly larger than reported at longer timescales for microbial consumption (Dawson et al 2012;Hulatt et al 2014;Stutter et al 2013) or photochemical degradation (Mann et al 2012;Worrall and Moody 2014). The strong negative correlation between reach-scale declines in DOC/POC and Mg and Si suggest that on most occasions apparent fluvial C losses are due to mixing with unmeasured sub-surface inputs of mineral-rich and POCor DOC-poor waters, rather than in-stream processing.…”

Section: Discussionmentioning

confidence: 71%

“…For catchments with varying proportions of peat cover in northern Finland, potential DOC biodegradation rates in laboratory incubations (nutrients were added to prevent nutrient limitation) ranged from 4.1 to 17.9 % (Hulatt et al 2014) and averaged 8.89 % (Asmala et al 2014a) during incubations lasting 55 and 39 days, respectively. In a batch experiment Stutter et al (2013) found that similar to other northern rivers, a maximum 19 % of DOM isolated from a Scottish moorland stream was biodegradable during 41-days incubation, and that the proportion of DOM decomposed could be predicted by DOM quality and 15 N content. Overall, these studies suggest that given time (on the order of days) and sufficient nutrients, biodegradation potentially removes up to 20 % of DOC from the water column in northern rivers.…”

Section: Introductionmentioning

confidence: 73%

Sporadic hotspots for physico-chemical retention of aquatic organic carbon: from peatland headwater source to sea

et al. 2015

View full text Add to dashboard Cite

Few studies have quantified the role of instream processes on net dissolved and particulate organic carbon (DOC and POC, respectively) export from peatland catchments, and those that have offer conflicting evidence. In this study, we evaluated evidence for active organic matter processing under field conditions, via a coordinated campaign across four UK catchments with peatland headwaters, targeted on potential 'hotspots' and 'hot moments' of physico-chemical carbon cycling. We hypothesised that specific hotspots and hot moments would occur where waters enriched with DOC and POC sourced from headwaters are exposed to: (1) mixing with freshwaters of different pH, conductivity and metal concentrations; and (2) mixing with seawater during autumn when DOC concentrations were at their highest. We observed instances of POC removal in headwaters, and potential for rapid conversion between dissolved and particulate carbon forms and for net removal of peat-derived carbon at confluences further downstream (where observed, on the order of 52-75 % for POC, and 5-44 % for DOC). Estuary transect surveys indicated that up to 30 % of fluvial DOC can be removed under high flow conditions. However, in the majority of cases concentrations remained within the range that would be expected based on conservative transport. These findings indicate that rapid (e.g. solubility-related) processes within the river system may be important but sporadic, thus are unlikely to provide major removal pathways for peat-derived organic carbon.

show abstract

“…This behavior can be verified by comparing treatments: T1 (irrigated without nitrogen), with T6 (not irrigated with 140kg ha -1 of N) that did not differ statistically, probably due to the increased rate of mineralization of soil organic matter in T1, which supplied the demand of N of the plant, resulting in an increase in productivity. Soil moisture has important effects on the mineralization of organic N, since it directly determines the availability of water for the activity and survival of microorganisms, thereby increasing the levels of mineralized nitrogen (COOK &ORCHARD, 2008 andSTUTTER et al, 2013). …”

Section: ---------------------------------(%)------------------------mentioning

confidence: 99%

Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization

Uribe

Gava²,

Saad

et al. 2013

Eng. Agríc.

View full text Add to dashboard Cite

ABSTRACT:The aim of this study was to compare the use of water and nitrogen on ratoon sugarcane during irrigated and rain-fed conditions, and to assess the production potential of stalks and sugar with different rates of N-fertilizer on the subsurface drip-irrigated management. The experimental design was a randomized block with four replications for each experiment and treatments: (T1) irrigated, 0kg N ha -1 ; (T2) irrigated, 70kg N ha -1 ; (T3) irrigated, 140kg N ha -1 ; (T4) irrigated, 210kg N ha -1 ; (T5) not irrigated, 0kg N ha -1 , and (T6) not irrigated, 140kg N ha -1 . Biometric, technological, dry matter and yield variables were analyzed among the treatments. The irrigation system together with the application of N-fertilizer at 140kg ha -1 presented significant differences in dry matter accumulation of shoots, and for the production of stalks and sugar, respectively 94, 105 and 106%, higher when compared to the not irrigated, without N-fertilizer (T5). There was a positive and synergistic effect of irrigation with N-fertilizer on the productivity of stalks and sugar. Ratoon sugarcane irrigated with subsurface dripping had the highest yield (22Mg ha -1 of sugar) with the dosage of 140kg ha -1 N.

show abstract

Biodegradability of natural dissolved organic matter collected from a UK moorland stream

Cited by 53 publications

References 45 publications

Origins and bioavailability of dissolved organic matter in groundwater

Origins and bioavailability of dissolved organic matter in groundwater

Sporadic hotspots for physico-chemical retention of aquatic organic carbon: from peatland headwater source to sea

Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization

Contact Info

Product

Resources

About