Research article 04 Jan 2013
Research article | 04 Jan 2013
Organic carbon and nitrogen export from a tropical dam-impacted floodplain system
R. Zurbrügg et al.
Related authors
No articles found.
Owen A. Sherwood, Samuel H. Davin, Nadine Lehmann, Carolyn Buchwald, Evan N. Edinger, Moritz F. Lehmann, and Markus Kienast
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-45, https://doi.org/10.5194/bg-2021-45, 2021
Preprint under review for BG
Short summary
Short summary
Pacific Water flowing eastward through the Canadian Arctic plays an important role in redistributing nutrients to the Northwest Atlantic Ocean. Using samples collected from northern Baffin Bay to the southern Labrador Shelf, we show that stable isotopic ratios in seawater nitrate reflect the fraction of Pacific to Atlantic Water. These results provide a new framework for interpreting patterns of nitrogen isotopic variability recorded in modern and archival organic materials in the region.
Sigrid van Grinsven, Kirsten Oswald, Bernhard Wehrli, Corinne Jegge, Jakob Zopfi, Moritz F. Lehmann, and Carsten J. Schubert
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-3, https://doi.org/10.5194/bg-2021-3, 2021
Revised manuscript accepted for BG
Yunhua Chang, Yan-Lin Zhang, Sawaeng Kawichai, Qian Wang, Martin Van Damme, Lieven Clarisse, Tippawan Prapamontol, and Moritz F. Lehmann
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1061, https://doi.org/10.5194/acp-2020-1061, 2021
Revised manuscript accepted for ACP
Short summary
Short summary
In this study, we integrated satellite constraints on atmospheric NH3 levels and fire intensity, discrete NH3 concentration measurement, and N isotopic analysis of NH3 in order to assess the regional-scale contribution of biomass burning to ambient atmospheric NH3 in the heartland of Southeast Asia. The combined approach provides a valuable cross-validation framework for source apportioning of NH3 in the lower atmosphere and will thus help to ameliorate predictions of biomass burning emissions.
Anna-Neva Visser, Scott D. Wankel, Pascal A. Niklaus, James M. Byrne, Andreas A. Kappler, and Moritz F. Lehmann
Biogeosciences, 17, 4355–4374, https://doi.org/10.5194/bg-17-4355-2020, https://doi.org/10.5194/bg-17-4355-2020, 2020
Short summary
Short summary
This study focuses on the chemical reaction between Fe(II) and nitrite, which has been reported to produce high levels of the greenhouse gas N2O. We investigated the extent to which dead biomass and Fe(II) minerals might enhance this reaction. Here, nitrite reduction was highest when both additives were present but less pronounced if only Fe(II) minerals were added. Both reaction systems show distinct differences, rather low N2O levels, and indicated the abiotic production of N2.
Adeline N. Y. Cojean, Jakob Zopfi, Alan Gerster, Claudia Frey, Fabio Lepori, and Moritz F. Lehmann
Biogeosciences, 16, 4705–4718, https://doi.org/10.5194/bg-16-4705-2019, https://doi.org/10.5194/bg-16-4705-2019, 2019
Short summary
Short summary
Our results demonstrate the importance of oxygen in regulating the fate of nitrogen (N) in the sediments of Lake Lugano south basin, Switzerland. Hence, our study suggests that, by changing oxygen concentration in bottom waters, the seasonal water column turnover may significantly regulate the partitioning between N removal and N recycling in surface sediments, and it is likely that a similar pattern can be expected in a wide range of environments.
Yunhua Chang, Yan-Lin Zhang, Jiarong Li, Chongguo Tian, Linlin Song, Xiaoyao Zhai, Wenqi Zhang, Tong Huang, Yu-Chi Lin, Chao Zhu, Yunting Fang, Moritz F. Lehmann, and Jianmin Chen
Atmos. Chem. Phys., 19, 12221–12234, https://doi.org/10.5194/acp-19-12221-2019, https://doi.org/10.5194/acp-19-12221-2019, 2019
Short summary
Short summary
The present work underscores the value of cloud water dissolved inorganic nitrogen isotopes as carriers of quantitative information on regional NOx and NH3 emissions. It sheds light on the origin and production pathways of nitrogenous species in clouds and emphasizes the importance of biomass-burning-derived nitrogenous species as cloud condensation nuclei in China’s troposphere. Moreover, it highlights the rapid evolution of NOx emissions in China.
Haoyi Yao, Wei-Li Hong, Giuliana Panieri, Simone Sauer, Marta E. Torres, Moritz F. Lehmann, Friederike Gründger, and Helge Niemann
Biogeosciences, 16, 2221–2232, https://doi.org/10.5194/bg-16-2221-2019, https://doi.org/10.5194/bg-16-2221-2019, 2019
Short summary
Short summary
How methane is transported in the sediment is important for the microbial community living on methane. Here we report an observation of a mini-fracture that facilitates the advective gas transport of methane in the sediment, compared to the diffusive fluid transport without a fracture. We found contrasting bio-geochemical signals in these different transport modes. This finding can help to fill the gap in the fracture network system in modulating methane dynamics in surface sediments.
Martin Ley, Moritz F. Lehmann, Pascal A. Niklaus, and Jörg Luster
Biogeosciences, 15, 7043–7057, https://doi.org/10.5194/bg-15-7043-2018, https://doi.org/10.5194/bg-15-7043-2018, 2018
Short summary
Short summary
Our laboratory study shows how microhabitat formation linked to soil aggregates, litter accumulation and plant soil interactions affects conditions under which
hot momentsof enhanced N2O emissions from floodplain soils during the drying phase after saturation occur. Larger aggregate size led to higher integrated flux rates when soil was unamended or mixed with leaf litter, whereas planting with willow significantly reduced emissions. Also, emission time patterns differed among the treatments.
Yunhua Chang, Yanlin Zhang, Chongguo Tian, Shichun Zhang, Xiaoyan Ma, Fang Cao, Xiaoyan Liu, Wenqi Zhang, Thomas Kuhn, and Moritz F. Lehmann
Atmos. Chem. Phys., 18, 11647–11661, https://doi.org/10.5194/acp-18-11647-2018, https://doi.org/10.5194/acp-18-11647-2018, 2018
Short summary
Short summary
We demonstrate that it is imperative that future studies, making use of isotope mixing models to gain conclusive constraints on the source partitioning of atmospheric NOx, consider this N isotope fractionation. Future assessments of NOx emissions in China (and elsewhere) should involve simultaneous δ15N and δ18O measurements of atmospheric nitrate and NOx at high spatiotemporal resolution, allowing former N-isotope-based NOx source partitioning estimates to be reevaluated more quantitatively.
Lea Steinle, Johanna Maltby, Tina Treude, Annette Kock, Hermann W. Bange, Nadine Engbersen, Jakob Zopfi, Moritz F. Lehmann, and Helge Niemann
Biogeosciences, 14, 1631–1645, https://doi.org/10.5194/bg-14-1631-2017, https://doi.org/10.5194/bg-14-1631-2017, 2017
Short summary
Short summary
Large amounts of methane are produced in anoxic, coastal sediments, from which it can seep into the overlying water column. Aerobic oxidation of methane (MOx) mediated by methanotrophic bacteria is an important sink for methane before its evasion to the atmosphere. In a 2-year seasonal study, we investigated the spatio-temporal variability of MOx in a seasonally hypoxic coastal inlet using radiotracer-based methods. In experiments, we assessed the effect of variable oxygen concentrations on MOx.
S. D. Wankel, C. Buchwald, W. Ziebis, C. B. Wenk, and M. F. Lehmann
Biogeosciences, 12, 7483–7502, https://doi.org/10.5194/bg-12-7483-2015, https://doi.org/10.5194/bg-12-7483-2015, 2015
Short summary
Short summary
In the sediments underlying the global oligotrophic ocean, low levels of microbial activity persist, despite low input of organic matter from surface ocean productivity. Using measured nitrogen and oxygen isotopes of porewater nitrate we estimate the magnitude and extent of microbial nitrogen cycling. We find evidence for the overlap of both denitrification as well as autotrophic pathways such as nitrification and nitrogen fixation, pointing to a relatively large role for subsurface autotrophy.
C. V. Freymond, C. B. Wenk, C. H. Frame, and M. F. Lehmann
Biogeosciences, 10, 8373–8383, https://doi.org/10.5194/bg-10-8373-2013, https://doi.org/10.5194/bg-10-8373-2013, 2013
M. Alkhatib, P. A. del Giorgio, Y. Gelinas, and M. F. Lehmann
Biogeosciences, 10, 7609–7622, https://doi.org/10.5194/bg-10-7609-2013, https://doi.org/10.5194/bg-10-7609-2013, 2013
Related subject area
Biogeochemistry: Rivers & Streams
Rapid soil organic carbon decomposition in river systems: effects of the aquatic microbial community and hydrodynamical disturbance
Increased carbon capture by a silicate-treated forested watershed affected by acid deposition
Spatial-temporal variations in riverine carbon strongly influenced by local hydrological events in an alpine headwater stream
Complex interactions of in-stream DOM and nutrient spiralling unravelled by Bayesian regression analysis
Thermokarst amplifies fluvial inorganic carbon cycling and export across watershed scales on the Peel Plateau, Canada
Temporary and net sinks of atmospheric CO2 due to chemical weathering in subtropical catchment with mixing carbonate and silicate lithology
From canals to the coast: dissolved organic matter and trace metal composition in rivers draining degraded tropical peatlands in Indonesia
Distribution and flux of dissolved iron in the peatland-draining rivers and estuaries of Sarawak, Malaysian Borneo
Comparisons of dissolved organic matter and its optical characteristics in small low and high Arctic catchments
High-frequency measurements explain quantity and quality of dissolved organic carbon mobilization in a headwater catchment
Dissolved inorganic nitrogen in a tropical estuary in Malaysia: transport and transformation
Behaviour of Dissolved Phosphorus with the associated nutrients in relation to phytoplankton biomass of the Rajang River-South China Sea continuum
Synchrony in catchment stream colour levels is driven by both local and regional climate
The post-monsoon carbon biogeochemistry of the Hooghly–Sundarbans estuarine system under different levels of anthropogenic impacts
Riverine particulate C and N generated at the permafrost thaw front: case study of western Siberian rivers across a 1700 km latitudinal transect
Geochemistry of the dissolved loads during high-flow season of rivers in the southeastern coastal region of China: anthropogenic impact on chemical weathering and carbon sequestration
CO2 partial pressure and CO2 emission along the lower Red River (Vietnam)
Stable isotopes of nitrate reveal different nitrogen processing mechanisms in streams across a land use gradient during wet and dry periods
Riverine carbon export in the arid to semiarid Wuding River catchment on the Chinese Loess Plateau
Use of argon to measure gas exchange in turbulent mountain streams
Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems – concepts, emerging trends, and research challenges
Shifts in stream hydrochemistry in responses to typhoon and non-typhoon precipitation
QUAL-NET, a high temporal-resolution eutrophication model for large hydrographic networks
Diel fluctuations of viscosity-driven riparian inflow affect streamflow DOC concentration
A comprehensive biogeochemical record and annual flux estimates for the Sabaki River (Kenya)
Hydro-ecological controls on dissolved carbon dynamics in groundwater and export to streams in a temperate pine forest
Regional-scale lateral carbon transport and CO2 evasion in temperate stream catchments
Carbon and nutrient export regimes from headwater catchments to downstream reaches
Influence of infrastructure on water quality and greenhouse gas dynamics in urban streams
Hydromorphological restoration stimulates river ecosystem metabolism
Quantifying nutrient fluxes with a new hyporheic passive flux meter (HPFM)
Sources, cycling and export of nitrogen on the Greenland Ice Sheet
Variability in runoff fluxes of dissolved and particulate carbon and nitrogen from two watersheds of different tree species during intense storm events
Shift in the chemical composition of dissolved organic matter in the Congo River network
Technical note: Assessing gas equilibration systems for continuous pCO2 measurements in inland waters
Source and flux of POC in a karstic area in the Changjiang River watershed: impacts of reservoirs and extreme drought
Sediment trap efficiency of paddy fields at the watershed scale in a mountainous catchment in northwest Vietnam
Along-stream transport and transformation of dissolved organic matter in a large tropical river
Global riverine N and P transport to ocean increased during the 20th century despite increased retention along the aquatic continuum
Optical properties and bioavailability of dissolved organic matter along a flow-path continuum from soil pore waters to the Kolyma River mainstem, East Siberia
Trace element transport in western Siberian rivers across a permafrost gradient
Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan
Stream biogeochemical and suspended sediment responses to permafrost degradation in stream banks in Taylor Valley, Antarctica
Runoff- and erosion-driven transport of cattle slurry: linking molecular tracers to hydrological processes
Dissolved organic carbon lability and stable isotope shifts during microbial decomposition in a tropical river system
Map-based prediction of organic carbon in headwater streams improved by downstream observations from the river outlet
Model-aided quantification of dissolved carbon and nitrogen release after windthrow disturbance in an Austrian karst system
Nitrogen export from a boreal stream network following forest harvesting: seasonal nitrate removal and conservative export of organic forms
Salinization alters fluxes of bioreactive elements from stream ecosystems across land use
Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems
Man Zhao, Liesbet Jacobs, Steven Bouillon, and Gerard Govers
Biogeosciences, 18, 1511–1523, https://doi.org/10.5194/bg-18-1511-2021, https://doi.org/10.5194/bg-18-1511-2021, 2021
Short summary
Short summary
We investigate the relative importance of two individual factors (hydrodynamical disturbance and aquatic microbial community) that possibly control SOC decomposition rates in river systems. We found aquatic microbial organisms led to rapid SOC decomposition, while effect of mechanical disturbance is relative minor. We propose a simple conceptual model: hydrodynamic disturbance is only important when soil aggregates are strong enough to withstand the disruptive forces imposed by water immersions.
Lyla L. Taylor, Charles T. Driscoll, Peter M. Groffman, Greg H. Rau, Joel D. Blum, and David J. Beerling
Biogeosciences, 18, 169–188, https://doi.org/10.5194/bg-18-169-2021, https://doi.org/10.5194/bg-18-169-2021, 2021
Short summary
Short summary
Enhanced rock weathering (ERW) is a carbon dioxide removal (CDR) strategy involving soil amendments with silicate rock dust. Over 15 years, a small silicate application led to net CDR of 8.5–11.5 t CO2/ha in an acid-rain-impacted New Hampshire forest. We accounted for the total carbon cost of treatment and compared effects with an adjacent, untreated forest. Our results suggest ERW can improve the greenhouse gas balance of similar forests in addition to mitigating acid rain effects.
Xin Wang, Ting Liu, Liang Wang, Zongguang Liu, Erxiong Zhu, Simin Wang, Yue Cai, Shanshan Zhu, and Xiaojuan Feng
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-472, https://doi.org/10.5194/bg-2020-472, 2020
Revised manuscript accepted for BG
Short summary
Short summary
We show a comprehensive monitoring dataset on the discharge and carbon dynamics in an alpine headwater stream (Shaliu River) on Qinghai-Tibetan Plateau, where riverine carbon increased downstream in pre-monsoon season due to increasing contribution of organic matter derived from seasonal permafrost thawing while fluctuated in the monsoon season induced by sporadic precipitation. These results indicate a high sensitivity of riverine carbon in alpine headwater streams to local hydrological events.
Matthias Pucher, Peter Flödl, Daniel Graeber, Klaus Felsenstein, Thomas Hein, and Gabriele Weigelhofer
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-372, https://doi.org/10.5194/bg-2020-372, 2020
Revised manuscript accepted for BG
Short summary
Short summary
Dissolved organic matter is an important carbon source in aquatic ecosystems, yet the uptake processes are not totally understood. We found evidence for the release of degradation products, efficiency loss with higher concentrations, stimulating effects and influences from the benthic zone. To conduct this analysis, we included interactions in the equations of the nutrient spiralling concept and solve it by a Bayesian non-linear fitting algorithm.
Scott Zolkos, Suzanne E. Tank, Robert G. Striegl, Steven V. Kokelj, Justin Kokoszka, Cristian Estop-Aragonés, and David Olefeldt
Biogeosciences, 17, 5163–5182, https://doi.org/10.5194/bg-17-5163-2020, https://doi.org/10.5194/bg-17-5163-2020, 2020
Short summary
Short summary
High-latitude warming thaws permafrost, exposing minerals to weathering and fluvial transport. We studied the effects of abrupt thaw and associated weathering on carbon cycling in western Canada. Permafrost collapse affected < 1 % of the landscape yet enabled carbonate weathering associated with CO2 degassing in headwaters and increased bicarbonate export across watershed scales. Weathering may become a driver of carbon cycling in ice- and mineral-rich permafrost terrain across the Arctic.
Yingjie Cao, Yingxue Xuan, Changyuan Tang, Shuai Guan, and Yisheng Peng
Biogeosciences, 17, 3875–3890, https://doi.org/10.5194/bg-17-3875-2020, https://doi.org/10.5194/bg-17-3875-2020, 2020
Short summary
Short summary
About half of the global CO2 sequestration due to chemical weathering occurs in warm and high-runoff regions. To evaluate the temporary and net sinks of atmospheric CO2 due to chemical weathering, we selected a typical subtropical catchment as our study area and did fieldwork to sample surface water along the main channel and major tributaries in 1 hydrological year. The result of mass balance calculation showed that human activities dramatically decreased the CO2 net sink.
Laure Gandois, Alison M. Hoyt, Stéphane Mounier, Gaël Le Roux, Charles F. Harvey, Adrien Claustres, Mohammed Nuriman, and Gusti Anshari
Biogeosciences, 17, 1897–1909, https://doi.org/10.5194/bg-17-1897-2020, https://doi.org/10.5194/bg-17-1897-2020, 2020
Short summary
Short summary
Worldwide, peatlands are important sources of dissolved organic matter (DOM) and trace metals (TMs) to surface waters, and these fluxes may increase with peatland degradation. In Southeast Asia, tropical peatlands are being rapidly deforested and drained. This work aims to address the fate of organic carbon and its role as a trace metal carrier in drained peatlands of Indonesia.
Xiaohui Zhang, Moritz Müller, Shan Jiang, Ying Wu, Xunchi Zhu, Aazani Mujahid, Zhuoyi Zhu, Mohd Fakharuddin Muhamad, Edwin Sien Aun Sia, Faddrine Holt Ajon Jang, and Jing Zhang
Biogeosciences, 17, 1805–1819, https://doi.org/10.5194/bg-17-1805-2020, https://doi.org/10.5194/bg-17-1805-2020, 2020
Short summary
Short summary
This study offered detailed information on dFe concentrations, distribution and the magnitude of yield in the Rajang River, the largest river in Malaysia. Three blackwater rivers, draining from peatlands, were also included in our study. Compared with the Rajang River, the dFe concentrations and yield from three blackwater rivers were much higher. The precipitation and agricultural activities, such as palm oil plantations, may markedly increase the concentration dFe in these tropical rivers.
Caroline Coch, Bennet Juhls, Scott F. Lamoureux, Melissa J. Lafrenière, Michael Fritz, Birgit Heim, and Hugues Lantuit
Biogeosciences, 16, 4535–4553, https://doi.org/10.5194/bg-16-4535-2019, https://doi.org/10.5194/bg-16-4535-2019, 2019
Short summary
Short summary
Climate change affects Arctic ecosystems. This includes thawing of permafrost (ground below 0 °C) and an increase in rainfall. Both have substantial impacts on the chemical composition of river water. We compared the composition of small rivers in the low and high Arctic with the large Arctic rivers. In comparison, dissolved organic matter in the small rivers is more susceptible to degradation; thus, it could potentially increase carbon dioxide emissions. Rainfall events have a similar effect.
Benedikt J. Werner, Andreas Musolff, Oliver J. Lechtenfeld, Gerrit H. de Rooij, Marieke R. Oosterwoud, and Jan H. Fleckenstein
Biogeosciences, 16, 4497–4516, https://doi.org/10.5194/bg-16-4497-2019, https://doi.org/10.5194/bg-16-4497-2019, 2019
Short summary
Short summary
Increased dissolved organic carbon (DOC) concentration in streams can pose a threat to downstream water resources. Analyzing data from an in-stream probe we found that hydroclimatic and hydrological drivers can describe up to 72 % of the observed DOC concentration and composition variability. Variability was found to be highest during discharge events with warm and dry preconditions. The findings suggest an impact of climate change on DOC exports and thus also on downstream water quality.
Shan Jiang, Moritz Müller, Jie Jin, Ying Wu, Kun Zhu, Guosen Zhang, Aazani Mujahid, Tim Rixen, Mohd Fakharuddin Muhamad, Edwin Sien Aun Sia, Faddrine Holt Ajon Jang, and Jing Zhang
Biogeosciences, 16, 2821–2836, https://doi.org/10.5194/bg-16-2821-2019, https://doi.org/10.5194/bg-16-2821-2019, 2019
Short summary
Short summary
Three cruises were conducted in the Rajang River estuary, Malaysia. The results revealed that the decomposition of terrestrial organic matter and the subsequent soil leaching were the main sources of dissolved inorganic nitrogen (DIN) in the fresh river water. Porewater exchange and ammonification enhanced DIN concentrations in the estuary water, while intensities of DIN addition varied between seasons. The riverine DIN flux could reach 101.5 ton(N) / d, supporting the coastal primary producers.
Edwin Sien Aun Sia, Jing Zhang, Shan Jiang, Zhuoyi Zhu, Gonzalo Carrasco, Faddrine Holt Jang, Aazani Mujahid, and Moritz Müller
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-219, https://doi.org/10.5194/bg-2019-219, 2019
Revised manuscript not accepted
Short summary
Short summary
Nutrient loads carried by large rivers and discharged into the continental shelf and coastal waters are vital to support primary production. Our knowledge of tropical river systems is fragmented with very few seasonal studies available for Southeast Asia (SEA). We present data from three sampling campaigns on the longest river in Malaysia, the Rajang river. Our results show the generalization of SEA as a nutrient hotspot might not hold true for all regions and requires further investigation.
Brian C. Doyle, Elvira de Eyto, Mary Dillane, Russell Poole, Valerie McCarthy, Elizabeth Ryder, and Eleanor Jennings
Biogeosciences, 16, 1053–1071, https://doi.org/10.5194/bg-16-1053-2019, https://doi.org/10.5194/bg-16-1053-2019, 2019
Short summary
Short summary
This study explores the drivers of variation in the water colour of rivers, and hence organic carbon export, in a blanket peatland catchment. We used 6 years of weekly river water colour data (2011 to 2016) from three proximate river sub-catchments in western Ireland. in tandem with a range of topographical, hydrological and climate data, to discover the principle environmental drivers controlling changes in colour concentration in the rivers.
Manab Kumar Dutta, Sanjeev Kumar, Rupa Mukherjee, Prasun Sanyal, and Sandip Kumar Mukhopadhyay
Biogeosciences, 16, 289–307, https://doi.org/10.5194/bg-16-289-2019, https://doi.org/10.5194/bg-16-289-2019, 2019
Short summary
Short summary
The study focused on understanding C biogeochemistry of two adjacently located estuaries undergoing different levels of anthropogenic stresses. Different parameters related to C cycling were measured in an anthropogenically influenced and a mangrove-dominated estuary. Although the entire estuarine system acted as a source of carbon dioxide to the regional atmosphere, emission approximately 17 times higher was noticed from the anthropogenically affected estuary compared to mangrove-dominated one.
Ivan V. Krickov, Artem G. Lim, Rinat M. Manasypov, Sergey V. Loiko, Liudmila S. Shirokova, Sergey N. Kirpotin, Jan Karlsson, and Oleg S. Pokrovsky
Biogeosciences, 15, 6867–6884, https://doi.org/10.5194/bg-15-6867-2018, https://doi.org/10.5194/bg-15-6867-2018, 2018
Short summary
Short summary
We tested the effect of climate, permafrost and physio-geographical landscape parameters on particulate C, N and P concentrations in small- and medium- sized rivers in the Western Siberian Lowland (WSL). We discovered a maximum of particulate C and N concentrations at the beginning of the permafrost appearance. A northward shift of permafrost boundaries may increase the particulate C and N export by WSL rivers to the Arctic Ocean by a factor of 2.
Wenjing Liu, Zhifang Xu, Huiguo Sun, Tong Zhao, Chao Shi, and Taoze Liu
Biogeosciences, 15, 4955–4971, https://doi.org/10.5194/bg-15-4955-2018, https://doi.org/10.5194/bg-15-4955-2018, 2018
Short summary
Short summary
The southeastern coastal region is the top acid-rain-impacted area in China. It is worth evaluating the acid deposition impacts on chemical weathering and CO2 consumption there. River water geochemistry evidenced an overestimation of CO2 sequestration if H2SO4/HNO3 involvement was ignored, which accounted for 33.6 % of the total flux by silicate weathering in this area. This study quantitatively highlights the anthropogenic acid effects on chemical weathering and associated CO2 consumption.
Thi Phuong Quynh Le, Cyril Marchand, Cuong Tu Ho, Nhu Da Le, Thi Thuy Duong, XiXi Lu, Phuong Kieu Doan, Trung Kien Nguyen, Thi Mai Huong Nguyen, and Duy An Vu
Biogeosciences, 15, 4799–4814, https://doi.org/10.5194/bg-15-4799-2018, https://doi.org/10.5194/bg-15-4799-2018, 2018
Short summary
Short summary
The Red River is a typical south-east Asian river, strongly affected by climate and human activity. This study showed the spatial and seasonal variability of CO2 emissions at the water–air interface of the lower part of this river due to natural conditions (meteo-hydrological-geomorphological characteristics) and human activities (dam impoundment, population, land use). The Red River water was supersaturated with CO2, providing a mean water–air CO2 flux of 530 ± 17 mmol m−2 d−1.
Wei Wen Wong, Jesse Pottage, Fiona Y. Warry, Paul Reich, Keryn L. Roberts, Michael R. Grace, and Perran L. M. Cook
Biogeosciences, 15, 3953–3965, https://doi.org/10.5194/bg-15-3953-2018, https://doi.org/10.5194/bg-15-3953-2018, 2018
Short summary
Short summary
Over-enrichment of nitrate can pose substantial risk to the quality of freshwater ecosystems. Hence, understanding the dynamics of nitrate is the key to better management of waterways. This study evaluates the relationship between the effects of land use and rainfall on the major sources and processing of nitrate within and between five streams in five catchments spanning an agricultural land use gradient. We found that rainfall exerted significant control over the fate of nitrate.
Lishan Ran, Mingyang Tian, Nufang Fang, Suiji Wang, Xixi Lu, Xiankun Yang, and Frankie Cho
Biogeosciences, 15, 3857–3871, https://doi.org/10.5194/bg-15-3857-2018, https://doi.org/10.5194/bg-15-3857-2018, 2018
Short summary
Short summary
We systematically assessed the transport and fate of riverine carbon in the moderate-sized Wuding catchment on the Chinese Loess Plateau by constructing a riverine carbon budget and further relating it to terrestrial ecosystem productivity. The riverine carbon export accounted for 16 % of the catchment's net ecosystem production (NEP). It seems that a significant fraction of terrestrial NEP in this catchment is laterally transported from the terrestrial biosphere to the drainage network.
Robert O. Hall Jr. and Hilary L. Madinger
Biogeosciences, 15, 3085–3092, https://doi.org/10.5194/bg-15-3085-2018, https://doi.org/10.5194/bg-15-3085-2018, 2018
Short summary
Short summary
Streams exchange oxygen with the atmosphere, but this rate is difficult to measure. We added argon to small mountain streams to estimate gas exchange. We compared these rates with sulfur hexafluoride, an intense greenhouse gas. Argon worked well to measure gas exchange, but had higher-than-predicted rates than sulfur hexafluoride. Argon exchange is more likely to represent that for oxygen because they share similar physical properties. We suggest argon to measure gas exchange in small streams.
Ji-Hyung Park, Omme K. Nayna, Most S. Begum, Eliyan Chea, Jens Hartmann, Richard G. Keil, Sanjeev Kumar, Xixi Lu, Lishan Ran, Jeffrey E. Richey, Vedula V. S. S. Sarma, Shafi M. Tareq, Do Thi Xuan, and Ruihong Yu
Biogeosciences, 15, 3049–3069, https://doi.org/10.5194/bg-15-3049-2018, https://doi.org/10.5194/bg-15-3049-2018, 2018
Short summary
Short summary
Human activities are drastically altering water and material flows in river systems across Asia. This review provides a conceptual framework for assessing the human impacts on Asian river C fluxes and an update on anthropogenic alterations of riverine C fluxes, focusing on the impacts of water pollution and river impoundments on CO2 outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia.
Chung-Te Chang, Jr-Chuan Huang, Lixin Wang, Yu-Ting Shih, and Teng-Chiu Lin
Biogeosciences, 15, 2379–2391, https://doi.org/10.5194/bg-15-2379-2018, https://doi.org/10.5194/bg-15-2379-2018, 2018
Short summary
Short summary
Our analysis of ion input–output budget illustrates that hydrochemical responses to typhoon storms are distinctly different from those of regular storms. In addition, even mild land use change may have large impacts on nutrient exports/losses. We propose that hydrological models should separate hydrochemical processes into regular and extreme conditions to better capture the whole spectrum of hydrochemical responses to a variety of climate conditions.
Camille Minaudo, Florence Curie, Yann Jullian, Nathalie Gassama, and Florentina Moatar
Biogeosciences, 15, 2251–2269, https://doi.org/10.5194/bg-15-2251-2018, https://doi.org/10.5194/bg-15-2251-2018, 2018
Short summary
Short summary
We developed the model QUALity-NETwork (QUAL-NET) to simulate water quality variations in large drainage networks. This model is accurate enough to represent processes occurring over short periods of time such as storm events and helps to fully understand water quality variations in stream networks in the context of climate change and varying human pressures. It was tested on the Loire River and provided good performances and a new understanding of the functioning of the river.
Michael P. Schwab, Julian Klaus, Laurent Pfister, and Markus Weiler
Biogeosciences, 15, 2177–2188, https://doi.org/10.5194/bg-15-2177-2018, https://doi.org/10.5194/bg-15-2177-2018, 2018
Short summary
Short summary
We studied the diel fluctuations of dissolved organic carbon (DOC) concentrations in a small stream in Luxembourg. We identified an increased proportion of DOC from terrestrial sources as responsible for the peaks in DOC in the afternoon. Warmer water temperatures in the riparian zone in the afternoon increased the amount of water flowing towards the stream. Consequently, an increased amount of DOC-rich water from the riparian zone was entering the stream.
Trent R. Marwick, Fredrick Tamooh, Bernard Ogwoka, Alberto V. Borges, François Darchambeau, and Steven Bouillon
Biogeosciences, 15, 1683–1700, https://doi.org/10.5194/bg-15-1683-2018, https://doi.org/10.5194/bg-15-1683-2018, 2018
Short summary
Short summary
A 2-year biogeochemical record provides annual sediment and element flux estimates for the non-dammed Sabaki River, Kenya, establishing a baseline for future research in light of impending construction of the first major upstream reservoir. Over 80 % of material fluxes occur across the wet season, with annual yields comparable to the adjacent, and dammed, Tana River. Observations at low-flow periods suggest large mammalian herbivores may be vectors of terrestrial subsidies to the water column.
Loris Deirmendjian, Denis Loustau, Laurent Augusto, Sébastien Lafont, Christophe Chipeaux, Dominique Poirier, and Gwenaël Abril
Biogeosciences, 15, 669–691, https://doi.org/10.5194/bg-15-669-2018, https://doi.org/10.5194/bg-15-669-2018, 2018
Short summary
Short summary
Carbon leaching to streams represents a very small (~ 2 %) fraction of forest net ecosystem exchange (NEE). Such weak export of carbon from forest ecosystems, at least in temperate regions, is at odds with recent studies that attempt to integrate the contribution of inland waters in the continent carbon budget. Understanding why local and global carbon mass balances strongly diverge on the proportion of land NEE exported to aquatic systems is a major challenge for research in this field.
Katrin Magin, Celia Somlai-Haase, Ralf B. Schäfer, and Andreas Lorke
Biogeosciences, 14, 5003–5014, https://doi.org/10.5194/bg-14-5003-2017, https://doi.org/10.5194/bg-14-5003-2017, 2017
Short summary
Short summary
We analyzed the relationship between terrestrial net primary production (NPP) and the rate at which carbon is exported from catchments in a temperate stream network. The carbon exported by streams and rivers corresponds to 2.7 % of the terrestrial NPP. CO2 evasion and downstream transport contribute about equally to this flux. A review of existing studies suggests that the catchment-specific carbon export varies in a relatively narrow range across different study regions and spatial scales.
Rémi Dupas, Andreas Musolff, James W. Jawitz, P. Suresh C. Rao, Christoph G. Jäger, Jan H. Fleckenstein, Michael Rode, and Dietrich Borchardt
Biogeosciences, 14, 4391–4407, https://doi.org/10.5194/bg-14-4391-2017, https://doi.org/10.5194/bg-14-4391-2017, 2017
Short summary
Short summary
Carbon and nutrient export regimes were analyzed from archetypal headwater catchments to
downstream reaches. In headwater catchments, land use and lithology determine
land-to-stream C, N and P transfer processes. The crucial role of riparian
zones in C, N and P coupling was investigated. In downstream reaches,
point-source contributions and in-stream processes alter C, N and P export
regimes.
Rose M. Smith, Sujay S. Kaushal, Jake J. Beaulieu, Michael J. Pennino, and Claire Welty
Biogeosciences, 14, 2831–2849, https://doi.org/10.5194/bg-14-2831-2017, https://doi.org/10.5194/bg-14-2831-2017, 2017
Short summary
Short summary
Urban streams receive excess nitrogen from numerous sources. We hypothesized that variations in carbon availability and subsurface infrastructure influence emissions of N2O and other greenhouse gases (CH4 and CO2) as excess N is utilized by microbes. We sampled eight streams draining four categories of stormwater and sanitary infrastructure. Dissolved nitrogen concentration was the strongest predictor of CO2 and N2O concentrations, while C : N ratio was the strongest predictor of CH4 in streams.
Benjamin Kupilas, Daniel Hering, Armin W. Lorenz, Christoph Knuth, and Björn Gücker
Biogeosciences, 14, 1989–2002, https://doi.org/10.5194/bg-14-1989-2017, https://doi.org/10.5194/bg-14-1989-2017, 2017
Short summary
Short summary
Modern ecosystem restoration should consider a wide range of environmental characteristics, including functional ones, such as rates and patterns of ecosystem metabolism. We show that hydromorphological river restoration enhanced habitat availability and abundance of macrophytes, promoting river primary productivity and respiration. Incorporating ecosystem functioning into monitoring programs enables a more holistic assessment of river health and a better understanding of restoration effects.
Julia Vanessa Kunz, Michael D. Annable, Jaehyun Cho, Wolf von Tümpling, Kirk Hatfield, Suresh Rao, Dietrich Borchardt, and Michael Rode
Biogeosciences, 14, 631–649, https://doi.org/10.5194/bg-14-631-2017, https://doi.org/10.5194/bg-14-631-2017, 2017
Short summary
Short summary
The hyporheic zone, the subsurface region of streams, is a key compartment for in-stream nutrient retention. Knowledge on actual hyporheic processing rates is still limited due to methodological restrictions which are mainly related to the high local and temporal variability of subsurface flow patterns and nutrient transformation processes. We present a new device which allows quantitative assessment of hyporheic nutrient fluxes and demonstrate its advantages in an exemplary field testing.
Jemma Louise Wadham, Jonathan Hawkings, Jon Telling, Dave Chandler, Jon Alcock, Emily O'Donnell, Preeti Kaur, Elizabeth Bagshaw, Martyn Tranter, Andre Tedstone, and Peter Nienow
Biogeosciences, 13, 6339–6352, https://doi.org/10.5194/bg-13-6339-2016, https://doi.org/10.5194/bg-13-6339-2016, 2016
Short summary
Short summary
Fjord and continental shelf environments in the polar regions are host to some of the planet's most productive ecosystems and support economically important fisheries. A key limiting nutrient for many of these marine phytoplankton is nitrogen. Here we evaluate the potential for a melting Greenland Ice Sheet to supply nitrogen to Arctic coastal ecosystems. We show nitrogen fluxes of a similar order of magnitude to one large Arctic river but yields that are double those typical of Arctic rivers.
Mi-Hee Lee, Jean-Lionel Payeur-Poirier, Ji-Hyung Park, and Egbert Matzner
Biogeosciences, 13, 5421–5432, https://doi.org/10.5194/bg-13-5421-2016, https://doi.org/10.5194/bg-13-5421-2016, 2016
Short summary
Short summary
Heavy storm events may increase the organic matter fluxes from forested watersheds and deteriorate water quality. Our study in two forested watershed in Korea revealed, that a larger proportion of coniferous forests likely leads to less organic carbon and larger of inorganic nitrogen fluxes to the receiving surface water bodies. More severe monsoon storms in the future will increase the fluxes of dissolved organic matter.
Thibault Lambert, Steven Bouillon, François Darchambeau, Philippe Massicotte, and Alberto V. Borges
Biogeosciences, 13, 5405–5420, https://doi.org/10.5194/bg-13-5405-2016, https://doi.org/10.5194/bg-13-5405-2016, 2016
Short summary
Short summary
This paper aims to investigate the spatial variability in dissolved organic matter (DOM) in terms of both concentration and composition in the Congo River network. Stable carbon isotopes and absorption and fluorescent properties of DOM were used as proxies for DOM composition. This study shows that DOM degradation within the Congo Basin results in the transition from aromatic to aliphatic DOM as well as the role of landscape and water residence time on this transition.
Tae Kyung Yoon, Hyojin Jin, Neung-Hwan Oh, and Ji-Hyung Park
Biogeosciences, 13, 3915–3930, https://doi.org/10.5194/bg-13-3915-2016, https://doi.org/10.5194/bg-13-3915-2016, 2016
Short summary
Short summary
Spray- and marble-type equilibrators and a membrane-enclosed CO2 sensor were compared to assess their suitability for continuous pCO2 measurements in inland waters. The results suggest that the fast response of the equilibration systems facilitates capturing large spatial variations in pCO2 during short underway measurements. The membrane-enclosed sensor would be suitable for long-term continuous measurements if biofouling could be overcome by antifouling measures such as copper mesh coverings.
Hongbing Ji, Cai Li, Huaijian Ding, and Yang Gao
Biogeosciences, 13, 3687–3699, https://doi.org/10.5194/bg-13-3687-2016, https://doi.org/10.5194/bg-13-3687-2016, 2016
Short summary
Short summary
The mineral composition, C / N ratios as well as 13C and 15N, of POC was firstly analyzed in suspended and surface sediments in the Wujiang River after the Three Gorges Dam began impounding sediment in 2004. A comparison of POC yield was made between karstic rivers and non-karstic rivers to evaluate the influence of carbonate distribution on POC transport. Considering the cascade reservoir and climate in the Wujiang River, the impacts of reservoirs and extreme drought were estimated in this study.
Johanna I. F. Slaets, Petra Schmitter, Thomas Hilger, Tran Duc Vien, and Georg Cadisch
Biogeosciences, 13, 3267–3281, https://doi.org/10.5194/bg-13-3267-2016, https://doi.org/10.5194/bg-13-3267-2016, 2016
Short summary
Short summary
Maize production on steep slopes causes erosion. Where the eroded material ends up is not well understood. This study assessed transport of sediment in mountainous Vietnam, where maize is cultivated on slopes and rice is cultivated in valleys. Per year, 64 tons per hectare of sediments are brought into the rice fields and 28 tons of those are deposited there. The sediment fraction captured by the paddies is mostly sandy, while fertile silt and clay are exported. Upland erosion thus impacts rice production.
Thibault Lambert, Cristian R. Teodoru, Frank C. Nyoni, Steven Bouillon, François Darchambeau, Philippe Massicotte, and Alberto V. Borges
Biogeosciences, 13, 2727–2741, https://doi.org/10.5194/bg-13-2727-2016, https://doi.org/10.5194/bg-13-2727-2016, 2016
Short summary
Short summary
This manuscript presents a detailed analysis of transport and transformation of dissolved organic matter along the Zambezi River and its largest tributary. A particular focus is put on the effects of floodplains/wetlands and reservoirs as well as low-flow vs. high-flow conditions on the longitudinal patterns in DOM concentration and composition. It is the first study to present such a detailed analysis for a whole, large river system, and in particular for a tropical river other than the Amazon.
Arthur H. W. Beusen, Alexander F. Bouwman, Ludovicus P. H. Van Beek, José M. Mogollón, and Jack J. Middelburg
Biogeosciences, 13, 2441–2451, https://doi.org/10.5194/bg-13-2441-2016, https://doi.org/10.5194/bg-13-2441-2016, 2016
Short summary
Short summary
Intensifying anthropogenic activity over the 20th century including agriculture, water consumption, urbanization, and aquaculture has almost doubled the global nitrogen (N) and phosphorus (P) delivery to streams and steadily increased the N : P ratio in freshwater bodies. Concurrently, the cumulative number of reservoirs has driven a rise in freshwater nutrient retention and removal. Still, river nutrient transport to the ocean has also nearly doubled, potentially stressing coastal environments.
Karen E. Frey, William V. Sobczak, Paul J. Mann, and Robert M. Holmes
Biogeosciences, 13, 2279–2290, https://doi.org/10.5194/bg-13-2279-2016, https://doi.org/10.5194/bg-13-2279-2016, 2016
Short summary
Short summary
In this study, we provide new findings with regards to the spatial distribution of dissolved organic matter (DOM) concentration, bioavailability, and optical properties during mid-summer hydrologic conditions throughout the Kolyma River basin in northeast Siberia. This is particularly critical for this region, where the future fate of organic carbon currently frozen in permafrost soils (and whether it ultimately is released as CO2 and CH4) is tightly linked to the lability of this material.
Oleg S. Pokrovsky, Rinat M. Manasypov, Sergey V. Loiko, Ivan A. Krickov, Sergey G. Kopysov, Larisa G. Kolesnichenko, Sergey N. Vorobyev, and Sergey N. Kirpotin
Biogeosciences, 13, 1877–1900, https://doi.org/10.5194/bg-13-1877-2016, https://doi.org/10.5194/bg-13-1877-2016, 2016
Short summary
Short summary
Climate change in western Siberia and permafrost boundary migration will essentially affect the elements controlled by underground water feeding (DIC, alkaline earth elements (Ca, Sr), oxyanions (Mo, Sb, As) and U). The thickening of the active layer may increase the export of trivalent and tetravalent hydrolysates in the form of organo-ferric colloids.
Jr-Chuan Huang, Tsung-Yu Lee, Teng-Chiu Lin, Thomas Hein, Li-Chin Lee, Yu-Ting Shih, Shuh-Ji Kao, Fuh-Kwo Shiah, and Neng-Huei Lin
Biogeosciences, 13, 1787–1800, https://doi.org/10.5194/bg-13-1787-2016, https://doi.org/10.5194/bg-13-1787-2016, 2016
Short summary
Short summary
The mean riverine DIN export of 49 watersheds in Taiwan is ∼ 3800 kg N km−2 yr−1, 18 times the global average. The mean riverine DIN export ratio is 0.30–0.51, which is much higher than the average of 0.20–0.25 of large rivers around the world, indicating excessive N input relative to ecosystem retention capacity. The DIN export ratio is positively related to agriculture input, and levels of human disturbance and watersheds with high DIN export ratios are likely at advanced stages of N excess.
Michael N. Gooseff, David Van Horn, Zachary Sudman, Diane M. McKnight, Kathleene A. Welch, and William B. Lyons
Biogeosciences, 13, 1723–1732, https://doi.org/10.5194/bg-13-1723-2016, https://doi.org/10.5194/bg-13-1723-2016, 2016
Short summary
Short summary
The landscape of the McMurdo Dry Valleys, Antarctica has been considered quite stable. In 2012, we discovered extensive permafrost degradation along several km of Crescent Stream. Here we document the responses to water quality, specifically changes to dissolved major ion and suspended sediment characteristics. Stream nitrate concentrations were greater than observed in the stream over the previous ~ 20 years, suggesting potentially significant impacts for stream and downstream lake ecosystems.
C. E. M. Lloyd, K. Michaelides, D. R. Chadwick, J. A. J. Dungait, and R. P. Evershed
Biogeosciences, 13, 551–566, https://doi.org/10.5194/bg-13-551-2016, https://doi.org/10.5194/bg-13-551-2016, 2016
Short summary
Short summary
Our interdisciplinary research brings together methodologies from hydrology, soil science and biogeochemistry to address key questions about the transport of cattle slurry in the environment. The paper provides a novel approach to trace dissolved and particulate components of cattle slurry through an experimental hillslope system. This work provides one of the first examples of using biomarkers to assess the effects of slope gradient and rainfall intensity on the movement of slurry derived-OM.
N. Geeraert, F. O. Omengo, G. Govers, and S. Bouillon
Biogeosciences, 13, 517–525, https://doi.org/10.5194/bg-13-517-2016, https://doi.org/10.5194/bg-13-517-2016, 2016
Short summary
Short summary
Rivers transport a large amount of carbon as dissolved organic carbon (DOC). Our incubation experiments on water of the Tana River, Kenya, showed that microbial decomposition of 10–60 % of the initial DOC occurred within the first 24–48 h. Simultaneously, there was a decrease in isotopic composition, indicating that DOC derived from C4 vegetation is preferentially decomposed. This has implications for the assessment of vegetation in a catchment based on isotope signatures of riverine carbon.
J. Temnerud, C. von Brömssen, J. Fölster, I. Buffam, J.-O. Andersson, L. Nyberg, and K. Bishop
Biogeosciences, 13, 399–413, https://doi.org/10.5194/bg-13-399-2016, https://doi.org/10.5194/bg-13-399-2016, 2016
Short summary
Short summary
In this study we test whether river outlet chemistry can be used as an additional source of information to improve the prediction of the total organic carbon (TOC) of headwaters, relative to models based on map information alone. Including river outlet TOC as a predictor in the models gave 5-15 % lower prediction errors than using map information alone. Thus, data on water chemistry measured at river outlets offer information which can complement GIS-based modelling of headwaters chemistry.
A. Hartmann, J. Kobler, M. Kralik, T. Dirnböck, F. Humer, and M. Weiler
Biogeosciences, 13, 159–174, https://doi.org/10.5194/bg-13-159-2016, https://doi.org/10.5194/bg-13-159-2016, 2016
Short summary
Short summary
We consider the time period before and after a wind disturbance in an Austrian karst system. Using a process-based flow and solute transport simulation model we estimate impacts on DIN and DOC. We show that DIN increases for several years, while DOC remains within its pre-disturbance variability. Simulated transit times indicate that impact passes through the hydrological system within some months but with a small fraction exceeding transit times of even a year.
J. Schelker, R. Sponseller, E. Ring, L. Högbom, S. Löfgren, and H. Laudon
Biogeosciences, 13, 1–12, https://doi.org/10.5194/bg-13-1-2016, https://doi.org/10.5194/bg-13-1-2016, 2016
Short summary
Short summary
The scientific question that is addressed in this study is how forest disturbance affects organic and inorganic nitrogen export from a boreal landscape. The key findings are that the mobilization of inorganic nitrogen from the terrestrial environment to streams increased strongly as a response to harvesting, but the stream network removed a major fraction of this load before it reached the outlet, while organic nitrogen was not removed and transported downstream.
S. Duan and S. S. Kaushal
Biogeosciences, 12, 7331–7347, https://doi.org/10.5194/bg-12-7331-2015, https://doi.org/10.5194/bg-12-7331-2015, 2015
Short summary
Short summary
There has been increased salinization of fresh water over decades during the urban evolution of watersheds. This study finds that salinization consistently increased sediment releases of labile organic carbon and total dissolved Kjeldahl nitrogen and sediment transformations of nitrate, and the salinization effects increased with percentage watershed urbanization. These findings are will be critical for forecasting changes in carbon and nutrient exports due to salt use in urban watersheds.
J. E. Vonk, S. E. Tank, W. B. Bowden, I. Laurion, W. F. Vincent, P. Alekseychik, M. Amyot, M. F. Billet, J. Canário, R. M. Cory, B. N. Deshpande, M. Helbig, M. Jammet, J. Karlsson, J. Larouche, G. MacMillan, M. Rautio, K. M. Walter Anthony, and K. P. Wickland
Biogeosciences, 12, 7129–7167, https://doi.org/10.5194/bg-12-7129-2015, https://doi.org/10.5194/bg-12-7129-2015, 2015
Short summary
Short summary
In this review, we give an overview of the current state of knowledge regarding how permafrost thaw affects aquatic systems. We describe the general impacts of thaw on aquatic ecosystems, pathways of organic matter and contaminant release and degradation, resulting emissions and burial, and effects on ecosystem structure and functioning. We conclude with an overview of potential climate effects and recommendations for future research.
Cited articles
Aalto, R., Maurice-Bourgoin, L., Dunne, T., Montgomery, D. R., Nittrouer, C. A., and Guyot, J. L.: Episodic sediment accumulation on Amazonian flood plains influenced by El Niño/Southern Oscillation, Nature, 425, 493–497, https://doi.org/10.1038/nature02002, 2003.
Alin, S. R., Aalto, R., Goni, M. A., Richey, J. E., and Dietrich, W. E.: Biogeochemical characterization of carbon sources in the strickland and fly rivers, Papua New Guinea, J. Geophys. Res.-Earth Surface, 113, F01s05, https://doi.org/10.1029/2006jf000625, 2008.
Alvarez-Cobelas, M., Angeler, D. G., Sanchez-Carrillo, S., and Almendros, G.: A worldwide view of organic carbon export from catchments, Biogeochemistry, 107, 275–293, https://doi.org/10.1007/s10533-010-9553-z, 2012.
Aufdenkampe, A. K., Mayorga, E., Hedges, J. I., Llerena, C., Quay, P. D., Gudeman, J., Krusche, A. V., and Richey, J. E.: Organic matter in the Peruvian headwaters of the Amazon: Compositional evolution from the Andes to the lowland Amazon mainstem, Org. Geochem., 38, 337–364, https://doi.org/10.1016/j.orggeochem.2006.06.003, 2007.
Battin, T. J., Luyssaert, S., Kaplan, L. A., Aufdenkampe, A. K., Richter, A., and Tranvik, L. J.: The boundless carbon cycle, Nature Geosci., 2, 598–600, https://doi.org/10.1038/ngeo618, 2009.
Berman, T. and Bronk, D. A.: Dissolved organic nitrogen: a dynamic participant in aquatic ecosystems, Aquat. Microb. Ecol., 31, 279–305, 2003.
Bernardes, M. C., Martinelli, L. A., Krusche, A. V., Gudeman, J., Moreira, M., Victoria, R. L., Ometto, J., Ballester, M. V. R., Aufdenkampe, A. K., Richey, J. E., and Hedges, J. I.: Riverine organic matter composition as a function of land use changes, Southwest Amazon, Ecol. Appl., 14, S263–S279, 2004.
Bouillon, S., Dehairs, F., Schiettecatte, L. S., and Borges, A. V.: Biogeochemistry of the Tana estuary and delta (northern Kenya), Limnol. Oceanogr., 52, 46–59, 2007.
Bouillon, S., Abril, G., Borges, A. V., Dehairs, F., Govers, G., Hughes, H. J.,Merckx, R., Meysman, F. J. R., Nyunja, J., Osburn, C., and Middelburg, J. J.: Distribution, origin and cycling of carbon in the Tana River (Kenya): a dry season basin-scale survey from headwaters to the delta, Biogeosciences, 6, 2475–2493, https://doi.org/10.5194/bg-6-2475-2009, 2009.
Bourbonnais, A., Lehmann, M. F., Waniek, J. J., and Schulz-Bull, D. E.: Nitrate isotope anomalies reflect N2 fixation in the Azores Front region (subtropical NE Atlantic), J. Geophys. Res.-Oceans, 114, https://doi.org/10.1029/2007jc004617, 2009.
Braman, R. S. and Hendrix, S. A.: Nanogram nitrite and nitrate determination in environmental and biological materials by vanadium(III) reduction with chemiluminescence detection, Anal. Chem., 61, 2715–2718, 1989.
Bronk, D. A., Lomas, M. W., Glibert, P. M., Schukert, K. J., and Sanderson, M. P.: Total dissolved nitrogen analysis: comparisons between the persulfate, UV and high temperature oxidation methods, Mar. Chem., 69, 163–178, 2000.
Casciotti, K. L., Sigman, D. M., Hastings, M. G., Böhlke, J. K., and Hilkert, A.: Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method, Anal. Chem., 74, 4905–4912, 2002.
Chen, F. J. and Jia, G. D.: Spatial and seasonal variations in $\delta ^{13}$C and δ15N of particulate organic matter in a dam-controlled subtropical river, River Res. Appl., 25, 1169–1176, https://doi.org/10.1002/rra.1225, 2009.
Chen, H. and Zheng, B. H.: Characterizing natural dissolved organic matter in a freshly submerged catchment (Three Gorges Dam, China) using UV absorption, fluorescence spectroscopy and PARAFAC, Water Sci. Technol., 65, 962–969, https://doi.org/10.2166/wst.2012.939, 2012.
Chen, W., Westerhoff, P., Leenheer, J. A., and Booksh, K.: Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter, Environ. Sci. Technol., 37, 5701–5710, https://doi.org/10.1021/es034354c, 2003.
Cleveland, C. C., Townsend, A. R., Schimel, D. S., Fisher, H., Howarth, R. W., Hedin, L. O., Perakis, S. S., Latty, E. F., Von Fischer, J. C., Elseroad, A., and Wasson, M. F.: Global patterns of terrestrial biological nitrogen (N2) fixation in natural ecosystems, Global Biogeochem. Cy., 13, 623–645, https://doi.org/10.1029/1999gb900014, 1999.
Coble, P. G.: Characterization of marine and terrestrial DOM in seawater using excitation emission matrix spectroscopy, Mar. Chem., 51, 325–346, 1996.
Cory, R. M., Miller, M. P., McKnight, D. M., Guerard, J. J., and Miller, P. L.: Effect of instrument-specific response on the analysis of fulvic acid fluorescence spectra, Limnol. Oceanogr.-Meth., 8, 67–78, 2010.
Cotner, J. B., Montoya, J. V., Roelke, D. L., and Winemiller, K. O.: Seasonally variable riverine production in the Venezuelan llanos, J. North Am. Benthol. Soc., 25, 171–184, https://doi.org/10.1899/0887-3593(2006)25[171:SVRPIT]2.0.CO;2, 2006.
Ellenbroek, G. A.: Ecology and productivity of an African wetland system. Geobotany 9, Dr. W. Junk, Dordrecht, 267 pp., 1987.
Ellis, E. E., Richey, J. E., Aufdenkampe, A. K., Krusche, A. V., Quay, P. D., Salimon, C., and da Cunha, H. B.: Factors controlling water-column respiration in rivers of the central and southwestern Amazon Basin, Limnol. Oceanogr., 57, 527–540, https://doi.org/10.4319/lo.2012.57.2.0527, 2012.
Galy, V. and Eglinton, T.: Protracted storage of biospheric carbon in the Ganges-Brahmaputra basin, Nature Geosci., 4, 843–847, https://doi.org/10.1038/ngeo1293, 2011.
Grasshoff, K., Kremling, K., and Ehrhardt, M.: Methods of Seawater Analysis, Third ed., Wiley-VCH, Weinheim, New York, Chichester Brisbane, Singapore, Tokyo, 632 pp., 1999.
Gu, B. and Alexander, V.: Estimation of N2 fixation based on differences in the natural-abundance of 15N among fresh-water N2-fixing and non-N2-fixing algae, Oecologia, 96, 43–48, 1993.
Hamilton, S. K. and Lewis, W. M.: Stable carbon and nitrogen isotopes in algae and detritus from the Orinoco River floodplain, Venezuela, Geochim. Cosmochim. Ac., 56, 4237–4246, 1992.
Harrison, J. A., Caraco, N., and Seitzinger, S. P.: Global patterns and sources of dissolved organic matter export to the coastal zone: Results from a spatially explicit, global model, Global Biogeochem. Cy., 19, Gb4s04 https://doi.org/10.1029/2005gb002480, 2005.
Hedges, J. I., Mayorga, E., Tsamakis, E., McClain, M. E., Aufdenkampe, A., Quay, P., Richey, J. E., Benner, R., Opsahl, S., Black, B., Pimentel, T., Quintanilla, J., and Maurice, L.: Organic matter in Bolivian tributaries of the Amazon River: A comparison to the lower mainstream, Limnol. Oceanogr., 45, 1449–1466, 2000.
Hoffmann, C. C., Kronvang, B., and Audet, J.: Evaluation of nutrient retention in four restored Danish riparian wetlands, Hydrobiologia, 674, 5–24, https://doi.org/10.1007/s10750-011-0734-0, 2011.
Hunsinger, G. B., Mitra, S., Findlay, S. E. G., and Fischer, D. T.: Wetland-driven shifts in suspended particulate organic matter composition of the Hudson River estuary, New York, Limnol. Oceanogr., 55, 1653–1667, 2010.
Ishii, S. K. L. and Boyer, T. H.: Behavior of reoccurring PARAFAC components in fluorescent dissolved organic matter in natural and engineered systems: A critical review, Environ. Sci. Technol., 46, 2006–2017, https://doi.org/10.1021/es2043504, 2012.
Johnson, M. S., Lehmann, J., Selva, E. C., Abdo, M., Riha, S., and Couto, E. G.: Organic carbon fluxes within and streamwater exports from headwater catchments in the southern Amazon, Hydrol. Process., 20, 2599–2614, https://doi.org/10.1002/hyp.6218, 2006.
Johnson, M. S., Couto, E. G., Abdo, M., and Lehmann, J.: Fluorescence index as an indicator of dissolved organic carbon quality in hydrologic flowpaths of forested tropical watersheds, Biogeochemistry, 105, 149–157, https://doi.org/10.1007/s10533-011-9595-x, 2011.
Kern, J. and Darwich, A.: The role of periphytic N2 fixation for stands of macrophytes in the whitewater floodplain (varzea), Amazoniana-Limnologia Et Oecologia Regionalis Systemae Fluminis Amazonas, 17, 361–375, 2003.
Knapp, A. N., Sigman, D. M., and Lipschultz, F.: N isotopic composition of dissolved organic nitrogen and nitrate at the Bermuda Atlantic time-series study site, Global Biogeochem. Cy., 19, GB1018, https://doi.org/10.1029/2004gb002320, 2005.
Kunz, M. J., Wüest, A., Wehrli, B., Landert, J., and Senn, D. B.: Impact of a large tropical reservoir on riverine transport of sediment, carbon, and nutrients to downstream wetlands, Water Resour. Res., 47, W12531, https://doi.org/10.1029/2011WR010996, 2011.
Lakowicz, J. R.: Principles of Fluorescence Spectroscopy, 3rd Edn., Springer, New York, 954 pp., 2006.
Martinelli, L. A., Victoria, R. L., Trivelin, P. C. O., Devol, A. H., and Richey, J. E.: N-15 natural abundance in plants of the Amazon River floodplain and potential atmospheric N2 fixation, Oecologia, 90, 591–596, 1992.
Mayorga, E., Aufdenkampe, A. K., Masiello, C. A., Krusche, A. V., Hedges, J. I., Quay, P. D., Richey, J. E., and Brown, T. A.: Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers, Nature, 436, 538–541, https://doi.org/10.1038/nature03880, 2005.
Mayorga, E., Seitzinger, S. P., Harrison, J. A., Dumont, E., Beusen, A. H. W., Bouwman, A. F., Fekete, B. M., Kroeze, C., and Van Drecht, G.: Global Nutrient Export from WaterSheds 2 (NEWS 2): Model development and implementation, Environ. Modell. Software, 25, 837–853, https://doi.org/10.1016/j.envsoft.2010.01.007, 2010.
McJannet, D., Wallace, J., Keen, R., Hawdon, A., and Kemei, J.: The filtering capacity of a tropical riverine wetland: II. Sediment and nutrient balances, Hydrol. Process., 26, 53–72, https://doi.org/10.1002/hyp.8111, 2012.
McKnight, D. M., Boyer, E. W., Westerhoff, P. K., Doran, P. T., Kulbe, T., and Andersen, D. T.: Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity, Limnol. Oceanogr., 46, 38–48, 2001.
Meier, P., Wang, H., Milzow, C., and Kinzelbach, W.: Remote sensing for hydrological modeling of seasonal wetlands – Concepts and applications, ESA Living Planet Symposium, 28 June–2 July 2010, Bergen, Norway, 2010,
Miller, M. P. and McKnight, D. M.: Comparison of seasonal changes in fluorescent dissolved organic matter among aquatic lake and stream sites in the Green Lakes Valley, J. Geophys. Res.-Biogeosci., 115, https://doi.org/10.1029/2009jg000985, 2010.
Mitsch, W. J. and Gosselink, J. G.: Wetlands, 4th Edn., John Wiley & Sons Inc., New Jersey, USA, 582 pp., 2007.
Mladenov, N., McKnight, D. M., Wolski, P., and Ramberg, L.: Effects of annual flooding on dissolved organic carbon dynamics within a pristine wetland, the Okavango Delta, Botswana, Wetlands, 25, 622–638, 2005.
Mumba, M., and Thompson, J. R.: Hydrological and ecological impacts of dams on the Kafue Flats floodplain system, southern Zambia, Phys. Chem. Earth, 30, 442–447, 2005.
Munyati, C.: Wetland change detection on the Kafue Flats, Zambia, by classification of a multitemporal remote sensing image dataset, Int. J. Remote Sens., 21, 1787–1806, 2000.
Noe, G. B. and Hupp, C. R.: Retention of riverine sediment and nutrient loads by coastal plain floodplains, Ecosystems, 12, 728–746, https://doi.org/10.1007/s10021-009-9253-5, 2009.
Olde Venterink, H., Wiegman, F., Van der Lee, G. E. M., and Vermaat, J. E.: Role of active floodplains for nutrient retention in the river Rhine, J. Environ. Qual., 32, 1430–1435, 2003.
Petrone, K. C., Fellman, J. B., Hood, E., Donn, M. J., and Grierson, P. F.: The origin and function of dissolved organic matter in agro-urban coastal streams, J. Geophys. Res.-Biogeosci., 116, 13, G01028, https://doi.org/10.1029/2010jg001537, 2011.
Raymond, P. A. and Bauer, J. E.: Riverine export of aged terrestrial organic matter to the North Atlantic Ocean, Nature, 409, 497–500, 2001.
Rejmankova, E., Komarkova, J., and Rejmanek, M.: δ15N as an indicator of N2-fixation by cyanobacterial mats in tropical marshes, Biogeochemistry, 67, 353–368, 2004.
Richey, J. E., Mertes, L. A. K., Dunne, T., Victoria, R. L., Forsberg, B. R., S., T. A. C. N., and E., O.: Sources and routing of the Amazon River flood wave, Global Biogeochem. Cy., 3, 191–204, 1989.
Richey, J. E., Hedges, J. I., Devol, A. H., Quay, P. D., Victoria, R., Martinelli, L., and Forsberg, B. R.: Biogeochemistry of carbon in the Amazon River, Limnol. Oceanogr., 35, 352–371, 1990.
Schlarbaum, T., Dähnke, K., and Emeis, K.: Dissolved and particulate reactive nitrogen in the Elbe River/NW Europe: a 2-yr N-isotope study, Biogeosciences, 8, 3519–3530, https://doi.org/10.5194/bg-8-3519-2011, 2011.
Schwendenmann, L., and Veldkamp, E.: The role of dissolved organic carbon, dissolved organic nitrogen, and dissolved inorganic nitrogen in a tropical wet forest ecosystem, Ecosystems, 8, 339–351, https://doi.org/10.1007/s10021-003-0088-1, 2005.
Sigman, D. M., Casciotti, K. L., Andreani, M., Barford, C., Galanter, M., and Böhlke, J. K.: A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater, Anal. Chem., 73, 4145–4153, 2001.
Solórzano, L. and Sharp, J. H.: Determination of total dissolved nitrogen in natural waters, Limnol. Oceanogr., 25, 751–754, 1980.
Spencer, R. G. M., Hernes, P. J., Ruf, R., Baker, A., Dyda, R. Y., Stubbins, A., and Six, J.: Temporal controls on dissolved organic matter and lignin biogeochemistry in a pristine tropical river, Democratic Republic of Congo, J. Geophys. Res.-Biogeosci., 115, G03013, https://doi.org/10.1029/2009jg001180, 2010.
Stedmon, C. A., Markager, S., and Bro, R.: Tracing dissolved organic matter in aquatic environments using a new approach to fluorescence spectroscopy, Mar. Chem., 82, 239–254, https://doi.org/10.1016/s0304-4203(03)00072-0, 2003.
Stedmon, C. A., and Markager, S.: Resolving the variability in dissolved organic matter fluorescence in a temperate estuary and its catchment using PARAFAC analysis, Limnol. Oceanogr., 50, 686–697, 2005.
Stedmon, C. A. and Bro, R.: Characterizing dissolved organic matter fluorescence with parallel factor analysis: a tutorial, Limnol. Oceanogr.-Meth., 6, 572–579, 2008.
Tamooh, F., Van den Meersche, K., Meysman, F., Marwick, T. R., Borges, A. V., Merckx, R., Dehairs, F., Schmidt, S., Nyunja, J., and Bouillon, S.: Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya, Biogeosciences, 9, 2905–2920, https://doi.org/10.5194/bg-9-2905-2012, 2012.
Tremblay, L. and Benner, R.: Organic matter diagenesis and bacterial contributions to detrital carbon and nitrogen in the Amazon River system, Limnol. Oceanogr., 54, 681–691, 2009.
Wamulume, J., Landert, J., Zurbrügg, R., Nyambe, I., Wehrli, B., and Senn, D. B.: Exploring the hydrology and biogeochemistry of the dam-impacted Kafue River and Kafue Flats (Zambia), Phys. Chem. Earth, 36, 775–788, https://doi.org/10.1016/j.pce.2011.07.049, 2011.
Waterloo, M. J., Oliveira, S. M., Drucker, D. P., Nobre, A. D., Cuartas, L. A., Hodnett, M. G., Langedijk, I., Jans, W. W. P., Tomasella, J., de Araujo, A. C., Pimentel, T. P., and Estrada, J. C. M.: Export of organic carbon in run-off from an Amazonian rainforest blackwater catchment, Hydrol. Process., 20, 2581–2597, https://doi.org/10.1002/hyp.6217, 2006.
Weishaar, J. L., Aiken, G. R., Bergamaschi, B. A., Fram, M. S., Fujii, R., and Mopper, K.: Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon, Environ. Sci. Technol., 37, 4702–4708, https://doi.org/10.1021/es030360x, 2003.
Wiegner, T. N., Tubal, R. L., and MacKenzie, R. A.: Bioavailability and export of dissolved organic matter from a tropical river during base- and stormflow conditions, Limnol. Oceanogr., 54, 1233–1242, https://doi.org/10.4319/lo.2009.54.4.1233, 2009.
Yamashita, Y., Maie, N., Briceno, H., and Jaffé, R.: Optical characterization of dissolved organic matter in tropical rivers of the Guayana Shield, Venezuela, J. Geophys. Res.-Biogeosci., 115, G00f10, https://doi.org/10.1029/2009jg000987, 2010a.
Yamashita, Y., Scinto, L. J., Maie, N., and Jaffé, R.: Dissolved organic matter characteristics across a subtropical wetland's landscape: Application of optical properties in the assessment of environmental dynamics, Ecosystems, 13, 1006–1019, https://doi.org/10.1007/s10021-010-9370-1, 2010b.
Ziegler, S. E. and Brisco, S. L.: Relationships between the isotopic composition of dissolved organic carbon and its bioavailability in contrasting Ozark streams, Hydrobiologia, 513, 153–169, https://doi.org/10.1023/B:hydr.0000018180.54292.47, 2004.
Zurbrügg, R., Wamulume, J., Kamanga, R., Wehrli, B., and Senn, D. B.: River-floodplain exchange and its effects on the fluvial oxygen regime in a large tropical river system (Kafue Flats, Zambia), J. Geophys. Res.-Biogeosci., 117, https://doi.org/10.1029/2011jg001853, 2012.
Altmetrics
Final-revised paper
Preprint