Article
Environmental Sciences
Alessandra Marzadri, Giuseppe Amatulli, Daniele Tonina, Alberto Bellin, Longzhu Q. Shen, George H. Allen, Peter A. Raymond
Summary: This study quantifies reach scale N2O emissions and identifies that small streams are the primary sources, contributing 50% of global riverine N2O emissions, while large rivers only contribute 26%. The research highlights the importance of considering small streams in local to global management and mitigation strategies for reducing N2O emissions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Geosciences, Multidisciplinary
Ed L. Pope, Maarten S. Heijnen, Peter J. Talling, Ricardo Silva Jacinto, Arnaud Gaillot, Megan L. Baker, Sophie Hage, Martin Hasenhundl, Catharina J. Heerema, Claire McGhee, Sean C. Ruffell, Stephen M. Simmons, Matthieu J. B. Cartigny, Michael A. Clare, Bernard Dennielou, Daniel R. Parsons, Christine Peirce, Morelia Urlaub
Summary: This study demonstrated the significant impact of flank collapses on submarine canyons, affecting morphology, sediment, and organic carbon fluxes.
Article
Multidisciplinary Sciences
Lourens J. J. Meijer, Tim van Emmerik, Ruud van der Ent, Christian Schmidt, Laurent Lebreton
Summary: Research shows that plastic waste in the marine environment mainly comes from rivers, with a model approach predicting the probability of plastic waste entering the ocean and identifying regions likely to emit plastic into the ocean. It is estimated that over 1000 rivers globally contribute to 80% of plastic waste emissions, with small urban rivers being the most polluting.
Article
Environmental Sciences
Barak Herut, Tamar Guy-Haim, Ahuva Almogi-Labin, Helmut W. Fischer, Daniela Ransby, Amir Sandler, Timor Katz, Simona Avnaim-Katav
Summary: Human activities have greatly reduced the transport of sediment and water to marine systems in the last two centuries. The construction of the Aswan High Dam has completely retained sediment in the Nile River. This river fragmentation has important implications for the Eastern Mediterranean ecosystem, leading to oligotrophication and hindering the retention of blue carbon.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Edgardo M. Latrubesse, Fernando M. D'Horta, Camila C. Ribas, Florian Wittmann, Jansen Zuanon, Edward Park, Thomas Dunne, Eugenio Y. Arima, Paul A. Baker
Summary: This article highlights the potentially large impacts of multiple new dams in the Amazon basin on specific biological groups, emphasizing the need for better understanding. Dams can disrupt river systems and decrease ecological connectivity among aquatic organisms and those dependent on seasonally flooded environments. The Dam Environmental Vulnerability Index (DEVI) is used to compare the hydrophysical impacts of proposed dams with biological diversity, showing a consistent relationship between DEVI values and species richness in the Amazon basin.
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS
(2021)
Article
Environmental Sciences
Fengxue Wu, Jingfu Wang, Shihao Jiang, Huaxian Zeng, Qixin Wu, Quan Chen, Jingan Chen
Summary: In this study, the interception of cascade dams on microplastics in the Wujiang River in China was investigated. The results showed that microplastics had higher abundance in the midstream, while lower pollution levels were observed in the upstream and downstream reaches. Plastic bags and polypropylene were the main plastic materials found. The abundance of microplastics was positively correlated with local GDP and negatively correlated with reservoir basin area. These findings contribute to our understanding of the migration of microplastics between terrestrial and marine ecosystems.
Article
Environmental Sciences
Anna Malago, Faycal Bouraoui
Summary: Nutrient emissions can have significant environmental impacts globally, with nitrogen surplus and phosphorus excess being major contributors to potential losses. Erosion and human wastewater also play important roles in nutrient pollution. Hotspots are identified in China and India, while localized high nitrogen rates are observed in Europe, Egypt, and North America.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Sagy Cohen, Jaia Syvitski, Thomas Ashely, Roderick Lammers, Balazs Fekete, Hong-Yi Li
Summary: Bedload is difficult to measure and model, and its dynamics in most fluvial systems worldwide remain unknown. This study presents a global scale bedload flux model that predicts the distribution of water discharge, suspended sediment, and bedload, and analyzes the sensitivity of bedload predictions to various factors. The results show that river discharge and slope are the key drivers of bedload trends.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
David M. Costello, Scott D. Tiegs, Luz Boyero, Cristina Canhoto, Krista A. Capps, Michael Danger, Paul C. Frost, Mark O. Gessner, Natalie A. Griffiths, Halvor M. Halvorson, Kevin A. Kuehn, Amy M. Marcarelli, Todd Royer, Devan M. Mathie, Ricardo J. Albarino, Clay P. Arango, Jukka Aroviita, Colden Baxter, Brent J. Bellinger, Andreas Bruder, Francis J. Burdon, Marcos Callisto, Antonio Camacho, Fanny Colas, Julien Cornut, Veronica Crespo-Perez, Wyatt F. Cross, Alison M. Derry, Michael M. Douglas, Arturo Elosegi, Elvira Eyto, Veronica Ferreira, Carmen Ferriol, Tadeusz Fleituch, Jennifer J. Follstad Shah, Andre Frainer, Erica A. Garcia, Liliana Garcia, Pavel E. Garcia, Darren P. Giling, R. Karina Gonzales-Pomar, Manuel A. S. Graca, Hans-Peter Grossart, Francois Guerold, Luiz U. Hepp, Scott N. Higgins, Takuo Hishi, Carlos Iniguez-Armijos, Tomoya Iwata, Andrea E. Kirkwood, Aaron A. Koning, Sarian Kosten, Hjalmar Laudon, Peter R. Leavitt, Aurea L. Lemes da Silva, Shawn J. Leroux, Carri J. LeRoy, Peter J. Lisi, Frank O. Masese, Peter B. McIntyre, Brendan G. McKie, Adriana O. Medeiros, Marko Milisa, Yo Miyake, Robert J. Mooney, Timo Muotka, Jorge Nimptsch, Riku Paavola, Isabel Pardo, Ivan Y. Parnikoza, Christopher J. Patrick, Edwin T. H. M. Peeters, Jesus Pozo, Brian Reid, John S. Richardson, Jose Rincon, Geta Risnoveanu, Christopher T. Robinson, Anna C. Santamans, Gelas M. Simiyu, Agnija Skuja, Jerzy Smykla, Ryan A. Sponseller, Franco Teixeira-de Mello, Sirje Vilbaste, Veronica D. Villanueva, Jackson R. Webster, Stefan Woelfl, Marguerite A. Xenopoulos, Adam G. Yates, Catherine M. Yule, Yixin Zhang, Jacob A. Zwart
Summary: Microbes play a critical role in plant litter decomposition and the fate of carbon in rivers and riparian zones. The process of nutrient immobilization, whereby microbes acquire nitrogen and phosphorus from the environment during the decomposition of low-nutrient plant litter, is influenced by nutrient loading and changing climate. However, environmental controls on immobilization are poorly understood due to the complex interplay between environmental factors and plant litter chemistry.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Michaela L. de Melo, Cristian R. Teodoru, Paul A. del Giorgio
Summary: This study conducted a large-scale survey of 23 major rivers in northern Quebec, finding significant variations in the concentrations of different carbon species, with methane showing the greatest variability. The study also found that the concentration of dissolved organic carbon decreased with an increase in water surface coverage, suggesting that it may primarily originate from water-land interfaces. Furthermore, for heavily dammed rivers, carbon emissions to the atmosphere approached the carbon export component. These findings are crucial for accurately quantifying carbon cycling in boreal rivers, understanding the sources and sinks of carbon, and predicting their responses to anthropogenic pressures and dynamic climate conditions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Multidisciplinary Sciences
Lucas J. Ustick, Alyse A. Larkin, Catherine A. Garcia, Nathan S. Garcia, Melissa L. Brock, Jenna A. Lee, Nicola A. Wiseman, J. Keith Moore, Adam C. Martiny
Summary: Nutrient supply affects phytoplankton activity, but understanding of global nutrient limitation and co-limitation is limited. Prochlorococcus adapt to local environments through gene gains and losses, with genomic changes indicating adaptation to nutrient stress. Regional transitions in stress type and severity, as well as widespread co-stress, were found, with correlations between Prochlorococcus stress genes, bottle experiments, and Earth system model predictions. The biogeography of multinutrient stress is linked through controls on nitrogen fixation, providing a detailed description of nutrient stress in the global ocean based on omics data.
Article
Meteorology & Atmospheric Sciences
Johannes Mayer, Michael Mayer, Leopold Haimberger, Chunlei Liu
Summary: This study uses reanalysis and observationally constrained fluxes to infer net surface energy fluxes and evaluate their accuracy. The results show that the inferred fluxes agree well with the observed heat uptake, while other flux products display large biases. It also provides indirect estimates of oceanic heat transport and compares inferred fluxes with buoy-based fluxes, revealing certain biases at different scales.
JOURNAL OF CLIMATE
(2022)
Article
Soil Science
Emma Hauser, Jon Chorover, Charles W. Cook, Daniel Markewitz, Craig Rasmussen, Daniel D. Richter, Sharon A. Billings
Summary: Nearly 50 years ago, Walker and Syers proposed the hypothesis that the sources of most terrestrial nutrients shift from mineral to organic matter as soils weather over millennia. By combining this soil development framework with vegetation dynamics, we investigated how it offers insights into ecosystem functioning. Our findings suggest that the dominant sources of tree phosphorus may shift from organic matter to minerals as roots expand during forest growth and encounter deeper soils. This highlights the importance of the interaction between dominant phosphorus form and root system growth for ecosystem phosphorus nutrition and soil development.
Article
Oceanography
Li Zhang, Yumin Yang, Weihong He, Jie Xu, Ruihuan Li
Summary: The Zhujiang River Estuary is experiencing eutrophication due to anthropogenic activities. Nutrient dynamics and fluxes to the Lingdingyang water through four outlets were investigated. Riverine fluxes of dissolved inorganic nitrogen (DIN) and dissolved silicate (DSi) varied seasonally, with the highest in spring and the lowest in winter. Riverine flux of phosphate showed little seasonal variability. Most riverine nutrients entered Lingdingyang water through Humen Outlet. Estuarine export fluxes of DIN were higher than riverine flux in May, potentially due to local sewage, while they were lower in August. Export fluxes of phosphate were higher than riverine flux in May and August. Large amounts of DSi were buried in the estuary in May and August. Despite excess DIN input, eutrophication effect was not severe due to light limitation.
ACTA OCEANOLOGICA SINICA
(2022)
Article
Limnology
Toshimi Nakajima, Ryo Sugimoto, Takahiro Kusunoki, Katsuhide Yokoyama, Makoto Taniguchi
Summary: The study found that oceanic water is the main source of nutrients for coastal ecosystems along the Sanriku Bay, but land-derived nutrients can also accelerate coastal primary production during certain seasons.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Geosciences, Multidisciplinary
C. B. Brinkerhoff, P. A. Raymond, T. Maavara, Y. Ishitsuka, K. S. Aho, C. J. Gleason
Summary: Lakes are key components of the inland water system and play a significant role in the degassing of soil CO2. The ability of lakes to evade CO2 is influenced by factors such as size and residence time, which in turn affect downstream CO2 transport.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Michelle E. Newcomer, Nicholas J. Bouskill, Haruko Wainwright, Taylor Maavara, Bhavna Arora, Erica R. Siirila-Woodburn, Dipankar Dwivedi, Kenneth H. Williams, Carl Steefel, Susan S. Hubbard
Summary: The patterns of watershed nitrogen retention and loss are influenced by various factors including atmospheric deposition, vegetation trends, and stream trends. The study identified two patterns of watershed nitrogen retention and loss, a hysteresis pattern and a one-way transition to a new state. Regions with increasing atmospheric deposition and vegetation health patterns have higher nitrogen retention capacity and experience declines in stream nitrogen exports.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Multidisciplinary Sciences
Taylor Maavara, Erica R. Siirila-Woodburn, Fadji Maina, Reed M. Maxwell, James E. Sample, K. Dana Chadwick, Rosemary Carroll, Michelle E. Newcomer, Wenming Dong, Kenneth H. Williams, Carl Steefel, Nicholas J. Bouskill
Summary: There is a growing understanding of the role of bedrock weathering as a nitrogen source in various environmental systems, especially in mountainous regions. However, the relative contributions of rock-derived nitrogen to nitrogen supply in mountainous watersheds are not well understood. The study developed a suite of models to quantify the sources, transformations, and sinks of geogenic and atmospheric nitrogen in a mountain watershed.
Article
Geosciences, Multidisciplinary
Maodian Liu, Qianru Zhang, Taylor Maavara, Shaoda Liu, Xuejun Wang, Peter A. Raymond
Summary: Rivers transport a significant amount of mercury annually to coastal oceans, three times more than atmospheric deposition. High flow events play a significant role in mercury export, with coastal oceans receiving the majority of external mercury input. Rivers are identified as the largest source of mercury to coastal oceans worldwide.
Article
Environmental Sciences
Taylor Maavara, Laura Logozzo, Aron Stubbins, Kelly Aho, Craig Brinkerhoff, Jacob Hosen, Peter Raymond
Summary: The study focuses on the photomineralization of dissolved organic carbon (DOC) in temperate rivers, specifically in the Connecticut River Watershed (CRW). Results show that photomineralization is a minor sink for DOC in temperate rivers, with varied rates across different flow conditions and seasons, but overall negligible compared to DOC fluxes.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2021)
Article
Geosciences, Multidisciplinary
R. Xu, H. Tian, N. Pan, R. L. Thompson, J. G. Canadell, E. A. Davidson, C. Nevison, W. Winiwarter, H. Shi, S. Pan, J. Chang, P. Ciais, S. R. S. Dangal, A. Ito, R. B. Jackson, F. Joos, R. Lauerwald, S. Lienert, T. Maavara, D. B. Millet, P. A. Raymond, P. Regnier, F. N. Tubiello, N. Vuichard, K. C. Wells, C. Wilson, J. Yang, Y. Yao, S. Zaehle, F. Zhou
Summary: We synthesized 17 bottom-up and 5 top-down estimates of N2O emissions over North America, finding a slight increase in emissions due to U.S. agriculture. Anthropogenic emissions were twice as large as natural fluxes, with the U.S. contributing the most. Agricultural emissions in the U.S. closely matched EPA inventory results, while Canada and Mexico had higher agricultural emissions than their national inventories.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Md Abdus Sabur, Christopher T. Parsons, Taylor Maavara, Philippe Van Cappellen
Summary: Adsorption experiments with goethite showed that maximum silicate adsorption occurred under alkaline conditions while the competitive effect of silicate on phosphate adsorption was more pronounced under alkaline conditions and elevated molar Si:P ratios (>4). Dissolved silicate did not affect phosphate desorption, even at high Si:P ratios and alkaline pH, indicating kinetic factors prevented silicate from displacing phosphate from goethite binding sites.
ACS EARTH AND SPACE CHEMISTRY
(2021)
Article
Environmental Sciences
Shaoda Liu, Taylor Maavara, Craig B. Brinkerhoff, Peter A. Raymond
Summary: The capacity of watersheds to eliminate or export reactive constituents has significant implications for aquatic ecosystem ecology and biogeochemistry. This study characterized the Damkohler number (Da) for dissolved organic carbon (DOC) uptake in global river networks. The results showed that watershed size is a primary controlling factor for river network DOC uptake, and tropical river networks have higher DOC uptake capacity compared to temperate and Arctic river networks. Additionally, river damming has a profound impact on DOC uptake, particularly in temperate watersheds.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Editorial Material
Environmental Sciences
Shaoda Liu, Taylor Maavara, Xiankun Yang, Lee E. Brown
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Limnology
Taylor Maavara, Craig Brinkerhoff, Jacob Hosen, Kelly Aho, Laura Logozzo, James Saiers, Aron Stubbins, Peter Raymond
Summary: River networks play an important role in transporting dissolved organic carbon (DOC) from land to the coastal ocean. The uptake of DOC in a river network is influenced by factors such as stream order, seasonal conditions, and flow. However, the dominance of biological or abiotic processes in DOC uptake and the partitioning of uptake between lakes and rivers are still unclear. In this study, a new model named CUPS-OF-DOC is presented to quantify DOC cycling in a river network, taking into account river-lake connectivity. The model is applied to the Connecticut River Watershed, revealing that the proportion of DOC uptake from photomineralization varies across different flow conditions and stream orders.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Review
Multidisciplinary Sciences
Tom J. Battin, Ronny Lauerwald, Emily S. Bernhardt, Enrico Bertuzzo, Lluis Gomez Gener, Robert O. Hall Jr, Erin R. Hotchkiss, Taylor Maavara, Tamlin M. Pavelsky, Lishan Ran, Peter Raymond, Judith A. Rosentreter, Pierre Regnier
Summary: River networks are the largest biogeochemical connection between land, ocean and atmosphere. Our understanding of the role of rivers in the global carbon cycle is limited, making it difficult to predict how global change will affect riverine carbon sequestration and greenhouse gas emissions. This review summarizes the current state of river ecosystem metabolism research and provides estimates of carbon flux from land to rivers. The study highlights the importance of a global river observing system in understanding river networks and their future evolution in the context of the global carbon budget.
Review
Environmental Sciences
Ronny Lauerwald, George H. Allen, Bridget R. Deemer, Shaoda Liu, Taylor Maavara, Peter Raymond, Lewis Alcott, David Bastviken, Adam Hastie, Meredith A. Holgerson, Matthew S. Johnson, Bernhard Lehner, Peirong Lin, Alessandra Marzadri, Lishan Ran, Hanqin Tian, Xiao Yang, Yuanzhi Yao, Pierre Regnier
Summary: This study reviews the progress made in estimating greenhouse gas (GHG) emissions from inland waters over the past decade, highlighting the remaining challenges and uncertainties. More empirical work is needed to reduce these uncertainties, particularly in understanding the contributions of specific areas and moments to overall GHG emissions.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Engineering, Civil
Wenqing Shi, Taylor Maavara, Qiuwen Chen, Jianyun Zhang, Jinren Ni, Daniele Tonina
Summary: This study investigated the greenhouse gas (GHG) emissions in a cascade hydropower system in the upper Mekong River, China. The results showed that GHG emissions were higher in cascade reservoirs compared to the upstream channel due to accumulated sediments. CO2 was the largest contributor to total CO2-eq, while N2O had a minimal contribution. The most upstream reservoir emitted the most CH4, possibly due to sediment accumulation.
JOURNAL OF HYDROLOGY
(2023)
Article
Environmental Sciences
Judith A. Rosentreter, Goulven G. Laruelle, Hermann W. Bange, Thomas S. Bianchi, Julius J. M. Busecke, Wei-Jun Cai, Bradley D. Eyre, Inke Forbrich, Eun Young Kwon, Taylor Maavara, Nils Moosdorf, Raymond G. Najjar, V. V. S. S. Sarma, Bryce Van Dam, Pierre Regnier
Summary: This article analyzes data from 738 observation sites and finds that coastal ecosystems have a certain absorption effect on greenhouse gases in the atmosphere, but methane and nitrous oxide emissions counteract the absorption of carbon dioxide. Southeast Asia, North America, and Africa are identified as hotspots for coastal greenhouse gas absorption.
NATURE CLIMATE CHANGE
(2023)
Article
Green & Sustainable Science & Technology
Tariq Aziz, Alain-Desire Nimubona, Philippe Van Cappellen
Summary: Economic valuations of ecosystem services often rely on transferring global unit values to the local context, but the reliability of this approach depends on the representativeness of the large-scale average unit values. This study compared local, regional, and global unit values to estimate the values of water filtration, nutrient cycling, and carbon sequestration in the Grand River watershed. The results showed that the global database provided significantly higher monetary values for ecosystem services compared to local and regional estimates. The research highlights the importance of critically assessing the origin of unit values and land cover resolution in ecosystem services valuation.
