Article
Environmental Sciences
Adam S. Wymore, Penny J. Johnes, Susana Bernal, E. N. Jack Brookshire, Hannah M. Fazekas, Ashley M. Helton, Alba Argerich, Rebecca T. Barnes, Ashley A. Coble, Walter K. Dodds, Shahan Haq, Sherri L. Johnson, Jeremy B. Jones, Sujay S. Kaushal, Pirkko Kortelainen, Carla Lopez-Lloreda, Bianca M. Rodriguez-Cardona, Robert G. M. Spencer, Pamela L. Sullivan, Christopher A. Yates, William H. McDowell
Summary: A comprehensive assessment of nitrogen species in stream water reveals shifts in dissolved nitrogen pool composition from highly heterogeneous to primarily inorganic nitrogen under nutrient enrichment from human disturbances. With increasing total dissolved nitrogen concentrations, inorganic nitrogen dominates the pool while dissolved organic nitrogen decreases. These changes in stoichiometry may have significant implications for global biogeochemical cycles of carbon and nitrogen in freshwater ecosystems.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Environmental Sciences
Kazumi Terada
Summary: This study investigated the impact of tidal changes on water quality and nutrient fluxes in a mangrove estuary in Japan. The results showed that there were differences in nutrient concentrations and fluxes between different years, and that the water and TN fluxes were influenced by rainfall.
MARINE ENVIRONMENTAL RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Arial J. Shogren, Jay P. Zarnetske, Benjamin W. Abbott, Samuel Bratsman, Brian Brown, Michael P. Carey, Randy Fulweber, Heather E. Greaves, Emma Haines, Frances Iannucci, Joshua C. Koch, Alexander Medvedeff, Jonathan A. O'Donnell, Leika Patch, Brett A. Poulin, Tanner J. Williamson, William B. Bowden
Summary: Repeated sampling of river chemistry in permafrost-affected Arctic watersheds provides comprehensive data and ecohydrological metrics to assess the location, scale, and persistence of carbon and nutrient contributions to watershed exports. The data allow estimation of novel ecohydrological metrics that describe the dominant location, scale, and overall persistence of ecosystem processes in continuous permafrost.
EARTH SYSTEM SCIENCE DATA
(2022)
Article
Environmental Sciences
Daniel Graeber, Youngdoung Tenzin, Marc Stutter, Gabriele Weigelhofer, Tom Shatwell, Wolf von Tuempling, Jorg Tittel, Alexander Wachholz, Dietrich Borchardt
Summary: We investigated the macronutrient-access hypothesis, which suggests that the balance between stoichiometric macronutrient demand and accessible macronutrients controls nutrient assimilation by aquatic heterotrophs. In a proof-of-concept experiment, we found that the ratios of bDOC:reactive N and bDOC:reactive P exerted a strong, predictable stoichiometric control on nutrient uptake. The study provides insights into the ecological stoichiometry and biogeochemistry of nutrient uptake in freshwater ecosystems, but further experiments are needed to validate the hypothesis.
Article
Engineering, Civil
Sarah H. Ledford, Shellby Miller, Luke Pangle, Elizabeth B. Sudduth
Summary: The rebound of beaver populations in North America has provided new insights into the effects of their alteration of stream channels on hydrology and biogeochemical cycling. However, their impact on urban areas has not been extensively studied. This research investigates the impact of urban beaver ponds on water quality, showing that they have the potential to improve water quality in urban streams and enhance ecological function in riparian zones.
JOURNAL OF HYDROLOGY
(2023)
Article
Engineering, Environmental
Kewei Liao, Sijia Ma, Caifeng Liu, Haidong Hu, Jinfeng Wang, Bing Wu, Hongqiang Ren
Summary: This study investigated the effects of low dissolved oxygen (DO) levels on dissolved organic nitrogen (DON) and N-nitrosodimethylamine (NDMA) precursor concentrations in biological nutrient removal (BNR) effluents. Surprisingly, lower DO levels were found to result in significantly higher levels of effluent DON and NDMA precursors. Ultrahigh-resolution mass spectrometry analysis revealed that molecules produced by microbes at low-DO levels may play critical roles in NDMA formation. Path analysis suggested that NDMA formation potential had strong associations with microbe-DON network stability.
Article
Environmental Sciences
Boqiang Li, Fei Yang, Baiyang Chen, Juan Li, Lijuan Zhu, Wen-Tao Li
Summary: Dissolved organic nitrogen (DON) plays a key role in various processes, but detecting it at trace levels is difficult due to high method detection limits (MDL). To solve this issue, researchers isolated DON from dissolved inorganic nitrogen (DIN) and used vacuum ultraviolet (VUV) and hydrogen peroxide to convert DON into nitrate for analysis. This method has improved analytical precision and lower MDL compared to conventional methods.
Article
Environmental Sciences
Young-Jae Jeong, Bo-Seong Seo, Nuri Baek, Jin-Hyeob Kwak, Sang-Mo Lee, Hyun-Jin Park, Woo-Jung Choi
Summary: This study proposed methods for determining the δN-15 of multiple nitrogen species. The methods included traditional distillation, direct evaporation, and isotope mass balance equation. The accuracy and precision of the methods were evaluated through a series of experiments, and the influences of different conditions on the analysis results were assessed.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Engineering, Environmental
Karim-Alexandre Essaied, Lucy Victoria Brown, Urs von Gunten
Summary: The composition of oxidant-reactive dissolved organic nitrogen (DON) is still not well characterized, but may form a variety of disinfection by-products containing nitrogen-oxygen bonds. Through oxidation and batch experiments, it was found that some amino acids have a high tendency to form nitrate (NO3), while other compounds have lower capabilities to form nitrate and chloramines.
Article
Ecology
Yang Yang, Stephen C. Hart, Emma P. McCorkle, Erin M. Stacy, Morgan E. Barnes, Carolyn T. Hunsaker, Dale W. Johnson, Asmeret Asefaw Berhe
Summary: Researchers analyzed water samples from eight low-order and mixed-conifer watersheds in the Sierra Nevada, California over five years to understand the temporal variation of water chemistry, finding that stream concentrations of DOC and dissolved N in Mediterranean headwater basins are highly variable over time due to climatic variabilities and management practices.
Article
Agronomy
Shaobo Wang, Puyu Feng, William D. Batchelor, Kelin Hu, Ji Li
Summary: Organic farming is considered sustainable for greenhouse vegetable production, but excessive use of organic manure can lead to high DON leaching. This study compared DIN and DON leaching under different farming systems, showing that organic systems had lower DIN leaching but higher DON leaching compared to conventional and integrated systems. Management strategies should be optimized to minimize DON leaching in organic farming.
Article
Environmental Sciences
Arne Verstraeten, Nicolas Bruffaerts, Fabiana Cristofolini, Elena Vanguelova, Johan Neirynck, Gerrit Genouw, Bruno De Vos, Peter Waldner, Anne Thimonier, Anita Nussbaumer, Mathias Neumann, Sue Benham, Pasi Rautio, Liisa Ukonmaanaho, Paeivi Merilae, Antti-Jussi Lindroos, Annika Saarto, Jukka Reiniharju, Nicholas Clarke, Volkmar Timmermann, Manuel Nicolas, Maria Schmitt, Katrin Meusburger, Anna Kowalska, Idalia Kasprzyk, Katarzyna Kluska, Lukasz Grewling, Malgorzata Malkiewicz, Lars Vesterdal, Morten Ingerslev, Miklos Manninger, Donat Magyar, Hugues Titeux, Gunilla Pihl Karlsson, Regula Gehrig, Sandy Adriaenssens, Agneta Ekebom, Asloeg Dahl, Marco Ferretti, Elena Gottardini
Summary: The effects of tree pollen on precipitation chemistry are not fully understood, which may lead to misinterpretations of element deposition in European forests. The study found that tree pollen has an impact on the element fluxes in forest throughfall, but the extent of the impact varies among different tree species.
Article
Engineering, Environmental
Min-Seob Kim, Bo Ra Lim, Pilyong Jeon, Seoyeon Hong, Darae Jeon, Si Yeong Park, Sunhwa Hong, Eun Jin Yoo, Hyoung Seop Kim, Sunkyoung Shin, Jeong Ki Yoon
Summary: This study successfully traced the sources of dissolved organic matter (DOM) in urban and rural river watersheds using multi-stable isotopes and spectroscopic indices. It found that soil and agricultural effluents were important anthropogenic sources of DOM, and their contributions varied with seasons. Molecular analysis also revealed the presence of pesticides and pharmaceuticals used in agriculture and livestock as significant components of DOM.
Article
Environmental Sciences
Zhou Liang, Robert T. Letscher, Angela N. Knapp
Summary: Surface ocean bulk and semi-labile dissolved organic matter (DOM) stoichiometry vary across ocean regions with global means of 387:26:1 and 179:20:1, respectively. Surface ocean DOC:DOP and DON:DOP concentration ratios are more variable than DOC:DON concentration ratios. Surface ocean gradients in P-depleted DOM stoichiometries in the Pacific and Atlantic basins reflect variable nutrient stress.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Multidisciplinary Sciences
Alexandra A. Phillips, Margot E. White, Michael Seidel, Fenfang Wu, Frank F. Pavia, Preston C. Kemeny, Audrey C. Ma, Lihini I. Aluwihare, Thorsten Dittmar, Alex L. Sessions
Summary: Marine dissolved organic matter (DOM) is a major reservoir that connects global carbon, nitrogen, and phosphorus cycles, and it is also the largest water column reservoir of organic sulfur. By analyzing the isotope ratios of different sources of dissolved organic sulfur (DOS), researchers found that DOS in the ocean mainly comes from phytoplankton-derived biomolecules rather than from sulfidic sediments. This study suggests that organic sulfur plays an important role in marine biogeochemistry beyond sulfate.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Geography, Physical
Jean E. Holloway, Scott F. Lamoureux, Scott N. Montross, Melissa J. Lafreniere
PERMAFROST AND PERIGLACIAL PROCESSES
(2016)
Article
Environmental Sciences
David M. Grewer, Melissa J. Lafreniere, Scott F. Lamoureux, Myrna J. Simpson
Article
Water Resources
Daniel Lamhonwah, Melissa J. Lafreniere, Scott F. Lamoureux, Brent B. Wolfe
HYDROLOGICAL PROCESSES
(2017)
Article
Environmental Sciences
M. A. Gillman, S. F. Lamoureux, M. J. Lafreniere
WATER RESOURCES RESEARCH
(2017)
Article
Engineering, Environmental
Jun-Jian Wang, Melissa J. Lafreniere, Scott F. Lamoureux, Andre J. Simpson, Yves Gelinas, Myrna J. Simpson
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2018)
Article
Biodiversity Conservation
Casper T. Christiansen, Melissa J. Lafreniere, Gregory H. R. Henry, Paul Grogan
GLOBAL CHANGE BIOLOGY
(2018)
Article
Geochemistry & Geophysics
David M. Grewer, Melissa J. Lafreniere, Scott F. Lamoureux, Myrna J. Simpson
ORGANIC GEOCHEMISTRY
(2018)
Article
Multidisciplinary Sciences
K. E. Roberts, S. F. Lamoureux, T. K. Kyser, D. C. G. Muir, M. J. Lafreniere, D. Iqaluk, A. J. Pienkowski, A. Normandeau
SCIENTIFIC REPORTS
(2017)
Article
Engineering, Environmental
Ana Cabrerizo, Derek C. G. Muir, Amila O. De Silva, Xiaowa Wang, Scott F. Lamoureux, Melissa J. Lafreniere
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2018)
Article
Multidisciplinary Sciences
C. R. Beel, S. F. Lamoureux, J. F. Orwin, M. A. Pope, M. J. Lafreniere, N. A. Scott
SCIENTIFIC REPORTS
(2020)
Article
Multidisciplinary Sciences
J. Fouche, C. T. Christiansen, M. J. Lafreniere, P. Grogan, S. F. Lamoureux
NATURE COMMUNICATIONS
(2020)
Article
Multidisciplinary Sciences
C. R. Beel, J. K. Heslop, J. F. Orwin, M. A. Pope, A. J. Schevers, J. K. Y. Hung, M. J. Lafreniere, S. F. Lamoureux
Summary: Climate warming is causing Arctic annual fluvial energy budgets to shift from snowmelt-dominated to snowmelt- and rainfall-dominated hydrological regimes, enhancing late summer and fall terrestrial-aquatic connectivity and higher material fluxes. Increased late summer rainfall enhances terrestrial-aquatic connectivity, but permafrost disturbances can reduce some organic carbon export.
NATURE COMMUNICATIONS
(2021)
Article
Environmental Sciences
J. K. Heslop, J. K. Y. Hung, H. Tong, M. J. Simpson, F. M. Chapman, N. Roulet, M. J. Lafreniere, S. F. Lamoureux
Summary: This study found that there are different geochemical and DOM compositions in ponds in undisturbed areas compared to disturbed areas in the High Arctic. Ponds in disturbed areas had lower DOC concentrations and higher proportions of autochthonous DOM, while ponds in undisturbed areas had characteristics suggesting allochthonous origin from modern vegetation.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Ecology
Caroline Coch, Bennet Juhls, Scott F. Lamoureux, Melissa J. Lafreniere, Michael Fritz, Birgit Heim, Hugues Lantuit
Article
Environmental Sciences
Cara N. Inglese, Casper T. Christiansen, Daniel Lamhonwah, Kristy Moniz, Scott N. Montross, Scott Lamoureux, Melissa Lafreniere, Paul Grogan, Virginia K. Walker
ARCTIC ANTARCTIC AND ALPINE RESEARCH
(2017)