Article
Soil Science
Nadine Loick, Elizabeth Dixon, G. Peter Matthews, Christoph Mueller, Veronica S. Ciganda, Maria Lopez-Aizpun, Miguel A. Repullo, Laura M. Cardenas
Summary: This study quantifies the production and consumption pathways of N2O in soil using labelled substrate-N, showing the impact of different water filled pore space on N-transformation processes and emissions. The research highlights the importance of heterotrophic nitrification and denitrification in the N2O emissions, demonstrating the complex relationship between water filled pore space and nitrogen transformations.
Article
Soil Science
Lei Song, Shuli Niu
Summary: Nitrification and denitrification, driven by microbes, play important roles in regulating soil nitrogen availability and nitrogen oxide (N2O) emissions. This study found that enhanced nitrogen deposition generally stimulates both nitrification and denitrification rates, particularly with longer durations of nitrogen addition. The abundances of functional genes AOB amoA and narG were crucial for these responses. These findings challenge the traditional understanding that long-term nitrogen deposition diminishes the positive response of N2O emissions by dampening microbial activity.
SOIL BIOLOGY & BIOCHEMISTRY
(2022)
Review
Environmental Sciences
Babita Aryal, Roshni Gurung, Aline F. Camargo, Gislaine Fongaro, Helen Treichel, Bandita Mainali, Michael J. Angove, Huu Hao Ngo, Wenshan Guo, Shukra Raj Puadel
Summary: The acceleration of the nitrogen cycle and nitrous oxide (N2O) emissions at an unprecedented rate has serious implications for the global ecosystem and climate change. The paper reviews how anthropogenic activities have disrupted the nitrogen cycle and estimates the future N2O-N emissions. The study emphasizes the importance of holistic mitigation strategies, policy reforms, and public awareness to tackle N2O emissions and their consequences.
ENVIRONMENTAL POLLUTION
(2022)
Review
Oceanography
Yutaka W. Watanabe, Yuto Nakano, Jun Nishioka, Masanori Ito
Summary: The study quantitatively investigated the processes affecting the flux of oceanic nitrogen gas in the Sea of Okhotsk and North Pacific Ocean, highlighting denitrification, air injection, and rapid cooling as significant factors influencing the flux of nitrogen gas in the region.
PROGRESS IN OCEANOGRAPHY
(2021)
Article
Green & Sustainable Science & Technology
Junnan Ding, Bin Li, Minglong Sun, Xin Li
Summary: This study aimed to explore the effects of three different cropping patterns on the abundance of nitrogen-cycling genes in saline-alkali soils. The results showed that rotation and mixture promoted soil nutrients and significantly influenced N-cycling functional genes. Rotation reduced the abundance of nifH, AOA, narG, and nosZ, while increasing the abundance of AOB. Mixture decreased the abundance of AOA, narG, and nosZ, while increasing the abundance of AOB and nxrB. Rotation and mixture not only reduced soil salinity but also improved soil fertility and nitrogen cycling.
Article
Agronomy
Ziyi Feng, Yongxiang Yu, Huaiying Yao, Chaorong Ge
Summary: This study found that the presence of ZnO nanoparticles can increase N2O emissions in soil, especially when coupled with C and N substrate amendments. The action of ZnO NPs promotes nitrification and denitrification processes, further impacting the functional genes associated with N2O emissions.
Article
Engineering, Environmental
Yuanyuan Miao, Liang Zhang, Deshuang Yu, Jianhua Zhang, Wenke Zhang, Guocheng Ma, Xinchao Zhao, Yongzhen Peng
Summary: Intermittent aeration is an effective strategy for biological wastewater treatment, allowing for advanced nitrogen removal and reduced energy consumption. It is suitable for partial nitrification and denitrification processes.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Environmental Sciences
Tanya Valkova, Vanessa Parravicini, Ernis Saracevic, Joseph Tauber, Karl Svardal, Jorg Krampe
Summary: N2O emissions in activated sludge tanks are mainly influenced by the activity of nitrifying bacteria and the efficiency of heterotrophic denitrification. Low-loaded plants achieving high nitrogen removal exhibit lower N2O emission intensity. The regression analysis shows a negative linear correlation between the N2O emission factor and the total nitrogen removal degree of the plants.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Environmental Sciences
Xinyi Yang, Pengpeng Duan, Guitong Li, Xiaorong Zhao, Qimei Lin, Kun Zhu
Summary: In this study, the application modes of organic fertilizer and chemical nitrogen fertilizer in soil were investigated, with the finding that spatial heterogeneous granulation of these fertilizers may increase the risk of nitrous oxide emissions, while a higher proportion of maize residues could potentially mitigate such increased emissions.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Engineering, Environmental
Shunan Zhang, Junli Chen, Feng Liu, Shuangtong Lv, Jinshui Wu
Summary: Free ammonia and free nitrous acid can inhibit the nitrogen removal ability of strain WT14, especially in alkaline conditions where strain WT14 exhibits higher tolerance and removal rates.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Agricultural Engineering
Yumeng Xie, Xiangli Tian, Yu He, Shuanglin Dong, Kun Zhao
Summary: Recently, functional microorganisms capable of eliminating nitrogenous waste have been used in mariculture systems. Strain DN3, a potential candidate for treating mariculture wastewater, showed a high efficiency in removing ammonia, nitrate, and nitrite at various concentrations and conditions. The nitrogen assimilation pathway and bacterial nitrification pathway were investigated, and the results provide important insight into the nitrogen metabolism of Halomonas sp. and support the use of strain DN3 for treating mariculture wastewater.
BIORESOURCE TECHNOLOGY
(2023)
Article
Biology
Sachia J. Traving, Colleen T. E. Kellogg, Tetjana Ross, Ryan McLaughlin, Brandon Kieft, Grace Y. Ho, Angelica Pena, Martin Krzywinski, Marie Robert, Steven J. Hallam
Summary: Recent studies have shown that marine heat waves can lead to shifts in prokaryotic community structures, with taxa considered free-living and chemoautotrophic prevailing under these unusual conditions. This shift may have implications for ocean productivity and organic carbon conversion and export.
COMMUNICATIONS BIOLOGY
(2021)
Article
Limnology
Connor H. H. Shea, Paul K. K. Wojtal, Hilary G. G. Close, Amy E. E. Maas, Karen Stamieszkin, Joseph S. S. Cope, Deborah K. K. Steinberg, Natalie Wallsgrove, Brian N. N. Popp
Summary: A study using nitrogen stable isotope analysis of amino acids reveals the trophic structure of mesopelagic zooplankton and provides insights into carbon and nitrogen sources in the subarctic northeast Pacific Ocean. Results show that small particles are the main basal resources for the food web, but surface organic matter from migrating zooplankton may also contribute. The length of the food web decreases significantly with depth, suggesting the importance of protistan microzooplankton in the mesopelagic zone.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Limnology
Karen Stamieszkin, Deborah K. Steinberg, Amy E. Maas
Summary: This study directly measured the fecal pellet carbon (FPC) production rates of mesozooplankton, finding that the production rate was 2.8 times higher at night compared to during the day, with the smallest size class contributing the most. In the subarctic Northeast Pacific Ocean, the pelagic tunicate Salpa aspera had the highest individual FPC production rate, while the large copepod Neocalanus cristatus dominated the 2.0-5.0 mm fraction but had a low FPC production rate.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Agriculture, Multidisciplinary
Samantha Earl-Goulet, William D. Talbot, Keith C. Cameron, Hong J. Di
Summary: The addition of plantain to pasture had no significant effect on N2O emissions from cattle urine patches. Soil type also had no significant effect on N2O emissions. However, urine application timing had a significant effect, with the highest emissions occurring in February.
NEW ZEALAND JOURNAL OF AGRICULTURAL RESEARCH
(2023)
Article
Environmental Sciences
Graham K. MacDonald, Julie Talbot, Tim R. Moore, Julien Arsenault, Sibeal McCourt, Aidan Goertzen, Max Emile Kessler-Nadeau, Kevin Manaugh, Roxane Maranger, Brian E. Robinson
ENVIRONMENTAL RESEARCH LETTERS
(2020)
Article
Biology
Nicolas F. St-Gelais, Jean-Francois Lapierre, Robert Siron, Roxane Maranger
Article
Limnology
Richard LaBrie, Simon Belanger, Ronald Benner, Roxane Maranger
Summary: This study utilizes empirical data and SpAD modeling to investigate the relationships among DOM compounds, metabolic processes, and prokaryotic diversity. Different SpAD taxonomic groups were found to be associated with specific organic compounds and metabolic rates. The study proposes a framework to bridge the gap between prokaryotic diversity, microbial ecology, and biogeochemistry across scales.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Ecology
Won-Kyung Lee, S. Kim Juniper, Maeva Perez, Se-Jong Ju, Se-Joo Kim
Summary: Research reveals differences in gill symbiont compositions among co-occurring vent invertebrate hosts, with distinct operational taxonomic units (OTUs) present and a greater total number of OTUs observed in crustacean hosts compared to mollusks. Phylogenetic relationship trees of gill symbionts suggest that gamma-proteobacterial symbionts coevolve with hosts to enhance host specificity, while campylobacterial Sulfurovum species are opportunistic associates found across various hosts and habitats.
ECOLOGY AND EVOLUTION
(2021)
Article
Genetics & Heredity
Maeva Perez, Bernard Angers, C. Robert Young, S. Kim Juniper
Summary: CRISPR can be used as a genetic marker to study the genetic structure of uncultured bacterial populations, which is important for conservation policies related to deep-sea microbial species. The research showed that CRISPR can reveal the impact of environmental conditions on symbiont diversity.
MICROBIAL GENOMICS
(2021)
Article
Limnology
Stephanie Shousha, Roxane Maranger, Jean-Francois Lapierre
Summary: The study found that carbon concentrations were stable along the river continuum, while nitrogen and phosphorus rapidly increased downstream due to urban and agricultural land uses. The dominant form of nitrogen shifted from dissolved organic nitrogen in forested reaches to nitrate in downstream areas. The spatial and temporal variation in stoichiometry of the north temperate river was influenced by human impacts and seasonal trends in temperature and hydrology.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Article
Multidisciplinary Sciences
Richard LaBrie, Berangere Pequin, Nicolas Fortin St-Gelais, Igor Yashayaev, Jennifer Cherrier, Yves Gelinas, Francois Guillemette, David C. Podgorski, Robert G. M. Spencer, Luc Tremblay, Roxane Maranger
Summary: The microbial carbon pump (MCP) hypothesis suggests that the transformation of labile dissolved organic carbon (DOC) by prokaryotes contributes to the stability of the deep ocean DOC reservoir. This study provides empirical evidence of the MCP in natural waters, showing that carbon sequestration is more efficient in deeper waters. The higher diversity of prokaryotes from the rare biosphere holds a greater metabolic potential in creating stable dissolved organic compounds.
Article
Environmental Sciences
Stephanie Shousha, Roxane Maranger, Jean-Francois Lapierre
Summary: This study quantified the changes in dissolved organic matter (DOM) composition and nutrient forms along a river with different land use and seasonal patterns. The results showed significant spatial and temporal shifts in DOM composition associated with different nutrient forms. These changes indicated contrasting loading and processing potential depending on land use and seasonal patterns.
Article
Environmental Sciences
M. Botrel, C. Hudon, J. B. Heffernan, P. M. Biron, R. Maranger
Summary: Our study revealed the significant influence of climate conditions on nitrogen pollution removal in large rivers, as well as on the abundance of underwater vegetation. Water temperature and level were found to be critical factors in determining plant abundance, with optimal conditions stimulating the growth of plants and promoting the removal of nitrogen pollution through denitrification by bacteria.
WATER RESOURCES RESEARCH
(2022)
Editorial Material
Biochemistry & Molecular Biology
Kelsey Leonard, Pier Luigi Buttigieg, Maui Hudson, Kenneth Paul, Jay Pearlman, S. Kim Juniper
Summary: Indigenous knowledge is often overlooked, resulting in missed opportunities for positive change. A two-eyed seeing approach that combines Indigenous and western knowledge systems can empower coastal Indigenous Peoples and bring advancements in protecting the Ocean.
Article
Environmental Sciences
J. O. Goyette, M. Botrel, G. Billen, J. Garnier, R. Maranger
Summary: This study analyzed the nitrogen and phosphorus fluxes in 78 watersheds of the St. Lawrence Basin in eastern Canada from 1901 to 2011 and found that the shift from sustainable to unsustainable agricultural practices over the past century has led to environmental losses. The study suggests reducing nutrient flux and reconnecting crop and animal farming to mitigate these losses.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Biodiversity Conservation
Morgan Botrel, Roxane Maranger
Summary: Submerged aquatic vegetation (SAV) in lake littoral zones is vital for maintaining ecosystem services, but global trends and drivers of SAV quantities remain unclear. This study provides a comprehensive synthesis of SAV trends using long-term time series data, revealing the dominant drivers of change in different regions. It highlights the urgent need for research and management actions to address knowledge gaps and preserve SAV and its crucial role in lake ecosystems.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Limnology
Morgan Botrel, Christiane Hudon, Pascale M. Biron, Roxane Maranger
Summary: Measuring biomass of freshwater submerged aquatic vegetation (SAV) at large spatial scales is challenging. The combination of quadrat-scuba diver technique, fast rake sampling, and large-scale echosounding can provide more accurate estimates. The relationship between quadrat and rake biomass varies with substrate type and SAV growth form, while rake biomass can be accurately estimated from biovolume derived from echosounding. Sequential application of calibrations can yield accurate predictions, with echosounding being more accurate at larger scales. A step-by-step guideline is developed to decide when to use each technique.
LIMNOLOGY AND OCEANOGRAPHY-METHODS
(2023)
Article
Environmental Sciences
Stephanie Shousha, Roxane Maranger, Jean-Francois Lapierre
Summary: This study investigates the long-term trends in carbon (C), nitrogen (N), and phosphorus (P) exports in a river system in Quebec, Canada. The results show that N exports have increased over time, largely driven by changes in precipitation and net anthropogenic N inputs on land. On the other hand, P exports have tended to decrease, despite higher net anthropogenic P inputs. The study also reveals changes in ecosystem stoichiometry over the years, reflecting the differential elemental exports influenced by natural and anthropogenic drivers.
GLOBAL BIOGEOCHEMICAL CYCLES
(2023)
Article
Limnology
Brett D. Jameson, Peter Berg, Damian S. Grundle, Catherine J. Stevens, S. Kim Juniper
Summary: Continental margin sediments play a significant role in marine nitrogen cycling and N2O emissions. N2O efflux increases with decreased oxygen penetration depth in sediments, emphasizing the importance of further investigating drivers of N2O production in these environments.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2021)