Dissolved Organic Matter

Bolan, Nanthi; Adriano, D. C.; Kunhikrishnan, Anitha; James, T.K.; McDowell, R. W.; Senesi, N.

doi:10.1016/b978-0-12-385531-2.00001-3

Cited by 449 publications

(105 citation statements)

References 416 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This has been shown for forest floors (Michalzik and Matzner, 1999;Gödde et al, 1996) as well as for wetland soils (Koehler et al, 2011;Clair et al, 2002). The mobilization of DOC from soil organic matter is partly driven by microbial (enzymatic) processes and partly by physicochemical processes (Bolan et al, 2011), both being temperature dependent. Hence, the steeper slope of the hysteretic loops and the more pronounced hysteresis in the summer/fall than in the winter/spring period seems largely due to a temperature effect on DOC mobilization.…”

Section: Temporal Dynamics Of Doc In Runoffmentioning

confidence: 78%

“…DOC plays an important role in the C cycle, in the acid-base chemistry of soils and surface waters, it influences nutrient cycling, and affects the mobility and availability of metals and contaminants (Bolan et al, 2011;Kalbitz et al, 2000). Although numerous studies on DOC in soils and catchments have been published in the last decade, sources and sinks of DOC in soils and the transition of DOC from terrestrial to the aquatic ecosystems are still poorly understood in their quantitative response to driving factors, like climatic conditions, flow paths, vegetation and soil conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Concentrations and fluxes of dissolved organic carbon in runoff from a forested catchment: insights from high frequency measurements

et al. 2013

View full text Add to dashboard Cite

Concentrations of dissolved organic carbon (DOC) in runoff from catchments are often subject to substantial short-term variations. The aim of this study was to identify the compartmental sources of DOC in a forested catchment and the causes for short-term variations in runoff. Furthermore, we investigated the implication of short-term variations for the calculation of annual runoff fluxes. High frequency measurements (30 min intervals) of DOC in runoff, of discharge and groundwater table were conducted for one year in the 4.2 km2 forested Lehstenbach catchment, Germany. Riparian wetland soils represent about 30% of the catchment area. The quality of DOC was investigated by three dimensional fluorescence excitation-emission matrices in samples taken from runoff, deep groundwater and shallow groundwater from the riparian wetland soils. The concentrations of DOC in runoff were highly variable at an hourly to daily time scale, ranging from 2.6 mg L−1 to 34 mg L−1 with an annual average of 9.2 mg L−1. The concentrations were positively related to discharge, with a counter clockwise hysteresis. Relations of DOC to discharge were steeper and the degree of hysteresis larger in the summer/fall than in the winter/spring period. Dynamics of groundwater table, discharge, DOC concentrations and DOC quality parameters indicated that DOC in runoff originated mainly from the riparian wetland soils, both under low and high flow conditions. The annual export of DOC from the catchment was 84 kg C ha−1 yr−1 when calculated from the high frequency measurements. If the annual export was calculated by simulated samplings of >2 days intervals substantial deviations resulted. Predicted changes in precipitation and discharge patterns as well as generally increasing temperatures likely will cause raising DOC exports from this catchment

show abstract

Section: Temporal Dynamics Of Doc In Runoffmentioning

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Concentrations and fluxes of dissolved organic carbon in runoff from a forested catchment: insights from high frequency measurements

et al. 2013

View full text Add to dashboard Cite

show abstract

“…DOC in soils is primarily the result of the enzymatic decomposition of litter and SOC, and it also originates from root exudates and from microbial residues that are not explicitly modeled. Simultaneously, microbial consumption of DOC is the main process of DOC removal from soil (Bolan et al, 2011). Since both are biological processes, it explains the high model sensitivity to these biological parameters.…”

Section: Doc Dynamics At the Site Levelmentioning

confidence: 99%

ORCHIDEE-SOM: modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe

et al. 2018

View full text Add to dashboard Cite

Abstract. Current land surface models (LSMs) typically represent soils in a very simplistic way, assuming soil organic carbon (SOC) as a bulk, and thus impeding a correct representation of deep soil carbon dynamics. Moreover, LSMs generally neglect the production and export of dissolved organic carbon (DOC) from soils to rivers, leading to overestimations of the potential carbon sequestration on land. This common oversimplified processing of SOC in LSMs is partly responsible for the large uncertainty in the predictions of the soil carbon response to climate change. In this study, we present a new soil carbon module called ORCHIDEE-SOM, embedded within the land surface model ORCHIDEE, which is able to reproduce the DOC and SOC dynamics in a vertically discretized soil to 2 m. The model includes processes of biological production and consumption of SOC and DOC, DOC adsorption on and desorption from soil minerals, diffusion of SOC and DOC, and DOC transport with water through and out of the soils to rivers. We evaluated ORCHIDEE-SOM against observations of DOC concentrations and SOC stocks from four European sites with different vegetation covers: a coniferous forest, a deciduous forest, a grassland, and a cropland. The model was able to reproduce the SOC stocks along their vertical profiles at the four sites and the DOC concentrations within the range of measurements, with the exception of the DOC concentrations in the upper soil horizon at the coniferous forest. However, the Published by Copernicus Publications on behalf of the European Geosciences Union. 938M. Camino-Serrano et al.: ORCHIDEE-SOM model was not able to fully capture the temporal dynamics of DOC concentrations. Further model improvements should focus on a plant-and depth-dependent parameterization of the new input model parameters, such as the turnover times of DOC and the microbial carbon use efficiency. We suggest that this new soil module, when parameterized for global simulations, will improve the representation of the global carbon cycle in LSMs, thus helping to constrain the predictions of the future SOC response to global warming.

show abstract

“…Dissolved organic matter (DOM) serves as a C and energy source for microorganisms and is an essential component of the global C and N cycles (Van Hees et al, 2005;Kalbitz and Kaiser, 2008;Bolan et al, 2011). Leaching of vegetation canopies, litterfall and soil organic matter are the most important sources of DOM (Kalbitz et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Response of Dissolved Carbon and Nitrogen Concentrations to Moderate Nutrient Additions in a Tropical Montane Forest of South Ecuador

2016

View full text Add to dashboard Cite

In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM) by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth. In 2007, we established a nutrient manipulation experiment (NUMEX) to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha −1 a −1 of nitrogen (N), 10 kg ha −1 a −1 of phosphorus (P), 50 kg + 10 kg ha −1 a −1 of N, and P and 10 kg ha −1 a −1 of calcium (Ca) in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes. Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC) and dissolved organic nitrogen (DON) concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments. Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO 3 -N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N and P. The current increasing reactive N deposition will increase N export from the root zone, while it will only accelerate TOC and DON turnover if P availability is simultaneously increased. The Saharan dust-related Ca deposition has no impact on TOC and DON turnover.

show abstract

Dissolved Organic Matter

Cited by 449 publications

References 416 publications

Concentrations and fluxes of dissolved organic carbon in runoff from a forested catchment: insights from high frequency measurements

Concentrations and fluxes of dissolved organic carbon in runoff from a forested catchment: insights from high frequency measurements

ORCHIDEE-SOM: modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe

Response of Dissolved Carbon and Nitrogen Concentrations to Moderate Nutrient Additions in a Tropical Montane Forest of South Ecuador

Contact Info

Product

Resources

About