Article
Geochemistry & Geophysics
Alexander A. Lopes, Vinicius B. Pereira, Leonardo Amora-Nogueira, Humberto Marotta, Luciane S. Moreira, Renato C. Cordeiro, Gabriela Vanini, Debora A. Azevedo
Summary: Different types of water in the Amazon rivers and flooded areas have a significant influence on the composition of sedimentary organic matter (SOM). Through geochemical assessment of floodplain lakes, it was found that black and clear water lakes are mainly influenced by terrigenous organic matter, while white water lakes are dominated by aquatic organisms. Water types also affect the production and degradation processes of organic matter.
ORGANIC GEOCHEMISTRY
(2021)
Article
Ecology
Joao Henrique Fernandes Amaral, John Michael Melack, Pedro Maia Barbosa, Alberto V. Borges, Daniele Kasper, Alicia Cortes Cortes, Wencai Zhou, Sally MacIntyre, Bruce Rider Forsberg
Summary: This study investigated the variations in CO2 concentration and related factors in a representative Amazon floodplain lake, finding that aquatic plant mats, water clarity, water level changes, and chlorophyll-a concentrations were key factors affecting CO2 concentration. CO2 concentrations in the lake were influenced by changes in inundation extent and exchange with vegetated habitats, and lateral exchanges of CO2 between vegetated habitats and open water were observed. The findings highlight the importance of flooded forests and aquatic herbaceous plants as sources of CO2 to open waters in tropical lakes and floodplains.
Article
Environmental Sciences
John M. Melack, Daniele Kasper, Joao H. F. Amaral, Pedro M. Barbosa, Bruce R. Forsberg
Summary: Limnological aspects of Amazon floodplain lakes are examined in the context of aquatic conservation, with a focus on understanding current variations and threats to ecological health. Studies have shown that the lakes are naturally variable and face direct threats from mining activities, mercury contamination, methylation, and deforestation. The cumulative responses to changes in catchments and inundation have major implications for the ecology of floodplain lakes, requiring expanded research and community-based management for conservation efforts.
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS
(2021)
Article
Geography, Physical
Derek K. Gibson, Broxton W. Bird, Harvie J. Pollard, Cameron A. Nealy, Robert C. Barr, Jaime Escobar
Summary: The study investigated flood frequencies on the lower Ohio River during the late Holocene, finding that the Medieval Climate Anomaly and Little Ice Age impacted flood frequencies in the region, while land clearing in the early 19th century decoupled flood frequencies from this relationship.
QUATERNARY SCIENCE REVIEWS
(2022)
Article
Environmental Sciences
Ayan S. Fleischmann, Fabrice Papa, Stephen K. Hamilton, Alice Fassoni-Andrade, Sly Wongchuig, Jhan-Carlo Espinoza, Rodrigo C. D. Paiva, John M. Melack, Etienne Fluet-Chouinard, Leandro Castello, Rafael M. Almeida, Marie-Paule Bonnet, Luna G. Alves, Daniel Moreira, Dai Yamazaki, Menaka Revel, Walter Collischonn
Summary: Extensive floodplains in the Amazon basin have important impacts on ecosystem services and global water and carbon cycles. Recent changes in the hydroclimatic regime have caused record-breaking high water levels on the Amazon River, but the implications for floodplain inundation across the basin are still unknown.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Editorial Material
Biochemistry & Molecular Biology
Ken W. Krauss
Summary: An expedition to the upper estuarine reaches of the Amazon River has found an intriguing overlap between tropical mangrove wetlands and riverine floodplain forests. This newly discovered type of forested wetland assemblage may serve as a uniquely process-rich carbon hotspot.
Article
Engineering, Environmental
Pei Lei, Jin Zhang, Jinjie Zhu, Qiaoguo Tan, Raymond W. M. Kwong, Ke Pan, Tao Jiang, Mohammad Naderi, Huan Zhong
Summary: This study reveals the impact of algal organic matter on microbial Hg methylators and MeHg production, showing that bioavailable components of AOM can increase the abundance and activity of methanogens, leading to enhanced levels of dissolved MeHg.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Biodiversity Conservation
Joao Vitor Campos-Silva, Carlos A. Peres, Joao Henrique Fernandes Amaral, Hugo Sarmento, Bruce Forsberg, Carlos Roberto Fonseca
Summary: Our study investigates the importance of bottom-up versus top-down drivers of phytoplankton biomass in tropical floodplain lakes. The results show that community-based fisheries management, controlling apex predators, is a strong predictor of phytoplankton biomass in dry seasons, while top-down forces play a significant role in primary productivity in tropical lakes. Management practices should consider both bottom-up and top-down factors to ensure biodiversity protection and sustainable fisheries yields.
JOURNAL OF APPLIED ECOLOGY
(2021)
Article
Geography, Physical
Laurentiu Tutuianu, Alfred Vespremeanu-Stroe, Luminita Preoteasa, Sabin Rotaru, Andreea Dima, Daniela Dimofte
Summary: This study focuses on the formation and transformations of wetlands and lakes in the lower reach of the Danube over the past 8000 years. The floodplain landscape underwent two main stages of changes, which were divided by a significant shift in sea levels. The analysis revealed that in the later stage, after sea-level rise decelerated, wetlands and lakes expanded, forming fine-grained sediments and peat deposits.
QUATERNARY INTERNATIONAL
(2021)
Article
Environmental Sciences
Xintong Jiang, Dong Liu, Junli Li, Hongtao Duan
Summary: Dissolved organic matter (DOM) plays a vital role in the global lake carbon cycle. This study focused on the changes in DOM components in different lake types based on in situ data from ten lakes in northwestern China. The results showed that human activities and salinity were the main contributors to the variations in DOM concentration and composition in the western arid lakes. The study also proposed a feasible flowchart for remotely estimating DOM in saline lakes using satellite data.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Civil
Alice Cesar Fassoni-Andrade, Rodrigo Cauduro Dias de Paiva, Sly Wongchuig, Claudio Barbosa, Fabien Durand, Thiago Sanna Freire Silva
Summary: This study used a 2D hydraulic model to analyze the hydrodynamics of the central Amazon River floodplain and found that the flows in the floodplain during floods are very intense, with a significant amount of inflow and outflow. The water extent in the floodplain remains relatively stable during floods, but the volume stored in the floodplain shows significant interannual variability.
JOURNAL OF HYDROLOGY
(2023)
Article
Geography, Physical
Yuji Ishii, Toru Tamura, Bunnarin Ben
Summary: This study reconstructs the Holocene sedimentary evolution of the Mekong River floodplain in Cambodia, showing rapid deposition in response to sea-level rise before 6.5 ka and localized levee accretion after 6.5 ka. This evolution is comparable to other large river systems in regions with weakening summer monsoons in the middle to late Holocene.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Geography, Physical
Bradley G. Johnson, Jacqueline A. Smith, Jared Maxwell Beeton
Summary: Terraces are formed by changes in sediment supply and hydrology and provide a valuable record of environmental change. This study examined terraces in the upper Rio Grande drainage to understand their formation and dynamics. The findings suggest that the terraces formed during glaciation and have experienced changes in fluvial processes since then.
Article
Biodiversity Conservation
Ziliang Li, Weijie Xu, Luyao Kang, Yakov Kuzyakov, Leiyi Chen, Mei He, Futing Liu, Dianye Zhang, Wei Zhou, Xuning Liu, Yuanhe Yang
Summary: The mineralization of dissolved organic matter (DOM) in thermokarst lakes plays an important role in the permafrost carbon cycle, but its complex interactions are not well understood. This study used large-scale lake sampling and laboratory incubations to investigate the patterns and drivers of DOM biodegradation. The results showed that labile carbon (C) and phosphorus (P) inputs stimulated DOM biodegradation, with the combined labile C and nutrient additions inducing stronger microbial mineralization. The intensity of aquatic priming was driven by DOM quality, while the P effect decreased with DOM recalcitrance.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Ecology
Flavia K. Siqueira-Souza, Lawrence E. Hurd, Kedma C. Yamamoto, Maria Gercilia M. Soares, Gregory J. Cooper, James R. Kahn, Carlos E. C. Freitas
Summary: The Amazon River Basin has a high diversity of fish species, with both white water and black water systems showing similar species richness but different species composition patterns. The study suggests that regional fish diversity cannot be accurately represented by sampling only one lake or one drainage system, but should include multiple lakes from both systems.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2021)
Article
Limnology
Juliana Nogueira, Heitor Evangelista, Lhoussaine Bouchaou, Luciane Moreira, Abdelfettah Sifeddine, Ahmed ElMouden, Fouad Msanda, Sandrine Caquineau, Francisco Javier Briceno-Zuluaga, Marcus Vinicius Licinio, Magloire Mandeng-Yogo, Mercedes Mendez-Millan, Renato C. Cordeiro, Bastiaan Knoppers, Manuel Moreira-Ramirez, Renato Martins
Summary: Coastal wetlands are highly sensitive to changes occurring at the coastline. This study focused on evaluating the impacts of recent climate changes at Khnifiss Lagoon in southern Morocco using remote sensing techniques and environmental reconstructions. The research highlighted changes in tidal channel morphology and an increase in organic carbon accumulation as responses to climate change, showing the sensitivity of the lagoon to large-scale processes.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Heitor Evangelista, Claudio de M. Valeriano, Gabriel Paravidini, Sergio J. Goncalves Junior, Eduardo D. Sodre, Carla C. A. Neto, Elaine A. Santos, Newton de M. Neto, Caroline Peixoto, Marcus V. V. J. Licinio, Joselito N. Ribeiro, Araceli Flores, Madson G. Pereira, Catia F. Barbosa, Joao R. C. de Barcellos, Bruno V. X. de Oliveira, Flavia Guebert, Fabio Negrao, Marcelino J. dos Anjos, Ramon Silva Santos, Jose Carlos Seoane, Renato Campello Cordeiro, Monica Heilbron
Summary: The Abrolhos bank is home to a rich coral reef system in the Southwestern Atlantic, but is facing challenges from marine heat waves and anthropogenic interventions. The collapse of the Fundao mining tailings dam in 2015 led to a significant influx of slurry into the Doce River, impacting sedimentation in the Abrolhos bank.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Geography, Physical
G. S. Martins, R. C. Cordeiro, B. Turcq, P. A. Meyers, M. Mendez-Millan, L. S. Moreira, D. Fontes, R. A. Rodrigues, A. Sifeddine, H. Behling, I. D. Bouloubassi
Summary: The molecular distributions and isotopic ratios of n-alkanes in sediments from Saci Lake in southeastern Amazonia provide important paleoclimate information. The results suggest dry conditions during the late Pleistocene and mid-Holocene, with a shift towards more humid conditions during the Holocene. The increase in plant biomass is shown to affect the isotopic signal.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geography, Physical
Juliano H. F. Soares, Luciane S. Moreira, Bruno Turcq, Patricia Moreira-Turcq, Abdel Sifeddine, Nayara Dornellas, Heitor Evangelista, Juliana Nogueira, Keila Aniceto, Gabriel S. Martins, Milena S. Kury, Nilva Brandini, Julia M. Contrera, Renato C. Cordeiro
Summary: In this study, sediment cores from nine lakes in the Brazilian Amazon Basin were analyzed to investigate the changes in lake production during the Holocene. Results showed that chlorophyll derivatives concentrations increased with precipitation rate, indicating a relationship between lake production and precipitation levels.
Article
Multidisciplinary Sciences
Leonardo Amora-Nogueira, Christian J. Sanders, Alex Enrich-Prast, Luciana Silva Monteiro Sanders, Rodrigo Coutinho Abuchacra, Patricia F. Moreira-Turcq, Renato Campello Cordeiro, Vincent Gauci, Luciane Silva Moreira, Fausto Machado-Silva, Renata Libonati, Thairiny Fonseca, Cristiane Nunes Francisco, Humberto Marotta
Summary: This study explores the importance of humid tropical forest lake sediments as a global sink for carbon, highlighting their implications for climate change and the key factors of temperature and forest conservation in maintaining massive organic carbon pools in tropical lacustrine sediments.
NATURE COMMUNICATIONS
(2022)
Article
Ecology
Claudia Veliz Rosas, Patricia Moreira-Turcq, Gerard Cochonneau, William Santini, Jean Loup Guyot
Summary: In the Amazon floodplains, hydrological variability plays a crucial role in shaping habitat and breeding areas. This study used satellite data and in-situ measurements to examine the relationship between water level variations and the start of oviposition. The results showed synchronous hydrological behavior between major and inner rivers, with oviposition correlating with water level in the main river stem. The study also found that the onset of the dry season influenced the timing of oviposition.
Article
Geography, Physical
David Noncent, Abdelfettah Sifeddine, Evens Emmanuel, Marie-Helene Cormier, Francisco J. Briceno-Zuluaga, Mercedes Mendez-Millan, Bruno Turcq, Sandrine Caquineau, Jorge Valdes, Juan Pablo Bernal, John W. King, Irina Djouraev, Fethiye Cetin, Heather Sloan
Summary: This study reconstructs the hydro-climatic variations in Haiti over the past 1000 years using mineralogical and geochemical composition of lake sediment core. The results show changes in sedimentological processes linked to environmental and climatic variations. The findings highlight the influence of anthropogenic activities on the current warm period and the impact of regional climate shifts on the hydro-climatic changes in Haiti.
Article
Ecology
Cristiane C. Thompson, Diogo Tschoeke, Felipe H. Coutinho, Luciana Leomil, Gizele D. Garcia, Koko Otsuki, Bruno J. Turcq, Luciane S. Moreira, Patricia F. M. Turcq, Renato C. Cordeiro, Nils E. Asp, Fabiano L. Thompson
Summary: This study investigated the microbial diversity of sediments in the Amazonian Airo Lake using metagenomics and biogeochemistry. Different depth layers of the sediment showed variation in microbial composition and provided insights into past microbial metabolism.
Article
Plant Sciences
M. Catrain, A-M Lezine, B. Turcq, T. Desjardins, M. Mandeng-Yogo, F. Cetin, G. Achoundong
Summary: This study examines the evolution of the Grassfields region in NW Cameroon over the past millennium by analyzing pollen content and organic matter from a 6-meter core recovered from a gallery forest near Lake Petpenoun. The core reveals two distinct periods: from 900 to 1420 CE, the coring site was submerged under lake water, indicating the expansion of the lake during the Medieval Climate Anomaly; from 1420 CE onward, the coring site gradually dried up during the Little Ice Age. A major event in 1420 CE led to changes in hydrological conditions and regional vegetation, as evidenced by the collapse of pollen production. (c) 2023 Elsevier B.V. All rights reserved.
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
(2023)
Article
Geosciences, Multidisciplinary
Marco Yseki, Bruno Turcq, Sandrine Caquineau, Renato Salvatteci, Jose Solis, C. Gregory Skilbeck, Federico Velazco, Dimitri Gutierrez
Summary: Reconstructing precipitation and wind dynamics from the geological record provides insight into the potential effects of climate change in Peru. This study focuses on the last deglaciation period and investigates the changes in terrigenous transport and sources in the central-southern Peruvian margin. The results suggest that river discharge and surface wind intensity were influenced by the Atlantic Meridional Overturning Circulation and the Walker circulation during the last deglaciation.
CLIMATE OF THE PAST
(2022)
Article
Agronomy
Liberio Junio da Silva, Deborah Pinheiro Dick, Djennifer Neckel, Gabriel Nuto Nobrega, Renato de Aragao R. Rodrigues, Reinaldo Imbrozio Barbosa, Renato Campello Cordeiro
Summary: This study analyzed the chemical composition of soil organic matter (SOM) in the border and interior of six forest fragments in the Roraima savanna in the northern Brazilian Amazon. The results showed no pronounced difference in SOM quality between the border and interior, indicating stability in the study area.
Article
Geosciences, Multidisciplinary
David Dominguez-Santos, Daniel Valderrama, Ahmet Utku Yazgan
Summary: This document presents a study comparing the spectra of large-magnitude seismic records in Chile between 2012 and 2022 with the design spectra of NCh433 and D. S 61. The aim is to determine if Chile's seismic-resistant regulations are updated to the existing reality and propose new design spectra that better represent the seismic activity in Chile during the last decade.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Prabhu Palanisamy, Vivek Sivakumar, Priya Velusamy, Logesh Natarajan
Summary: Shoreline changes in the southern coast of Rio de Janeiro, Brazil, were analyzed from 1986 to 2018. The study found that both natural and human factors significantly impact shoreline changes. The findings provided important insights into predicting future shoreline positions and identifying vulnerable regions. Additionally, human activities were found to influence shoreline change models, emphasizing the need for effective management strategies to protect ecosystems and communities.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Irina Salgado Bernal, Periyasamy Sivalingam, Armando Martinez Sardina, Michel Manduca Artiles, Maria E. Carballo Valdes, John Pote
Summary: This study investigated the presence of 15 toxic metals in surface sediment in a tropical river ecosystem in Cuba. The results showed that the sediments had higher concentrations of four metals compared to Cuban norms. Various contamination indices were calculated, and correlations analysis revealed the main sources of contamination. The study provides important information for the management of the river and emphasizes the need for metal pollution control and monitoring.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Camila Morgan, Eduardo Morgado, Miguel-Angel Parada, Raimundo Brahm, Francisca Mallea-Lillo
Summary: Lanin volcano is a composite volcano in the Andes, which has erupted lava flows with different compositions. The volcano's magma reservoir contains a crystal mush, and the pre-eruptive conditions include temperature, pressure, and oxygen fugacity. Fractional crystallisation has led to the evolution of the magma with different compositions.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2024)
Article
Geosciences, Multidisciplinary
Benjamin Idini, Sergio Ruiz, Jean-Paul Ampuero, Felipe Leyton, Efrain Rivera
Summary: This study investigates the role of wedge integrity on the frequency content of strong ground motion produced by subduction earthquakes in Northern Chile. The results show that the frequency characteristics of seismic waves vary with hypocentral distance, indicating lateral variations in anelastic attenuation due to the heterogeneous tectonic structure.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2024)
