Article
Environmental Sciences
Erik J. L. Larson, Luke D. Schiferl, Roisin Commane, J. William Munger, Anna T. Trugman, Takeshi Ise, Eugenie S. Euskirchen, Steve Wofsy, Paul M. Moorcroft
Summary: A significant amount of carbon is stored in the Arctic permafrost, and its fate is uncertain due to complex biophysical, ecological, and biogeochemical processes. Improved understanding of these processes is crucial for predicting the future of Arctic peatlands. This study analyzes a vertically-resolved model of peatland soil carbon and finds that increased precipitation and warming have led to declines in net ecosystem productivity since 2013.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Ecology
Diane C. Huebner, Agata Buchwal, M. Syndonia Bret-Harte
Summary: Thermokarst disturbance in permafrost landscapes is likely to increase with climate warming, resulting in changes to topography, vegetation, and biogeochemical cycling. This study on shrub-thermokarst relationships in Alaska's North Slope found that thermokarst activity had strong successional effects on shrub growth, with shrubs in retrogressive thaw slumps (RTSs) showing wider growth rings compared to undisturbed areas. Climate effects on shrub growth varied across species and sites, but overall, a higher June temperature and increased September precipitation were associated with wider growth rings. This research highlights the importance of understanding the impacts of thermokarst activity on tundra shrubs and the potential contribution of retrogressive thaw slumps to tundra greening.
Article
Geography, Physical
Ian G. Droppo, Peter di Cenzo, Renee McFadyen, Thomas Reid
Summary: Studies have shown that significant amounts of sediment are released into lakes and rivers even at the stabilization phase of retrogressive thaw slump scars (RTSSs), potentially impacting the ecological health of lakes. Eroded particles in RTS sediments are primarily individual clay particles smaller than 5 micrometers, indicating a potential significant ecological impact on lake ecosystems.
PERMAFROST AND PERIGLACIAL PROCESSES
(2022)
Article
Geosciences, Multidisciplinary
Mei Mu, Cuicui Mu, Hebin Liu, Haiteng Chi, Yongji Zhu, Jianguo Shang, Chengyan Fan, Xiaodong Wu, Guofei Zhang
Summary: A study conducted in the northern Qinghai-Tibetan Plateau found that permafrost collapse led to the loss of soil organic carbon and nitrogen, weakening carbon sinks. The study also revealed that soil temperature, moisture, and nutrient availability were the main controlling factors of carbon emissions during permafrost collapse.
Article
Environmental Sciences
Chenglong Jiao, Yizhao Wang, Yi Shan, Peifeng He, Junlin He
Summary: Thermokarst terrain, including retrogressive thaw slumps, is rapidly developing on the ice-rich permafrost of the Qinghai-Tibet Plateau in China. However, the impacts of freeze-thaw erosion caused by thermokarsts, especially in terms of sediment migration, have not been quantified due to limitations in hydro-thermal-mass transport laws. This study developed a coupled model to simulate the geotemperature regime and groundwater flow in a retrogressive thaw slump area, allowing for the quantification of permafrost thaw and mass wasting. The results showed significant seepage velocities in the superficial zone, an average thaw volume of 13.4 m(2), and a cumulative mass transport volume of 22 m(2). The relationship between freeze-thaw erosion and ground ice ablation can be described by an exponential equation. This work provides a reliable method for quantifying the effects of freeze-thaw erosion and assessing the eco-environmental impacts of retrogressive thaw slumps.
LAND DEGRADATION & DEVELOPMENT
(2023)
Article
Biochemistry & Molecular Biology
Linwei Wu, Felix Yang, Jiajie Feng, Xuanyu Tao, Qi Qi, Cong Wang, Edward A. G. Schuur, Rosvel Bracho, Yi Huang, James R. Cole, James M. Tiedje, Jizhong Zhou
Summary: Microorganisms in subsurface soils showed reduced metabolic capacities in response to warming, likely due to increased thaw depth and altered microbial community compositions and functional structures. Bacterial and fungal abundances decreased significantly in the deep organic layer with warming, while fungal community composition and microbial functional structure were impacted. Environmental factors such as water saturation, soil moisture, and soil thaw duration played a role in shaping microbial communities in the subsurface soil layers.
Article
Geosciences, Multidisciplinary
S. A. Pedron, R. G. Jespersen, X. Xu, Y. Khazindar, J. M. Welker, C. I. Czimczik
Summary: Snow is crucial to the Arctic's energy budget, biogeochemistry, ecology, and people. While climate change shortens the snow cover period, snow mass has been increasing in many Arctic regions. Deeper snow thaws permafrost and releases ancient organic matter, contributing to greenhouse gas emissions. However, more snow also leads to warmer soil temperatures and increased carbon loss, impacting Arctic ecosystems and accelerating permafrost carbon release.
Article
Engineering, Environmental
Wenting Zhou, Tian Ma, Xiufeng Yin, Xiaodong Wu, Quanlian Li, Dipesh Rupakheti, Xin Xiong, Qianggong Zhang, Cuicui Mu, Benjamin de Foy, Maheswar Rupakheti, Shichang Kang, Dahe Qin
Summary: Thaw slumps in permafrost regions can lead to significant carbon loss, but the contribution of microbial and plant-derived carbon in this process is not well understood. In a permafrost thaw slump in the Tibetan Plateau, the study provides direct evidence that microbial necromass carbon is a major component of the lost carbon. Microbial necromass carbon accounted for approximately 54% of the soil organic carbon loss in the thaw slump.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Environmental
Guanqin Wang, Leiyi Chen, Dianye Zhang, Shuqi Qin, Yunfeng Peng, Guibiao Yang, Jun Wang, Jianchun Yu, Bin Wei, Yang Liu, Qinlu Li, Luyao Kang, Yuanyuan Wang, Yuanhe Yang
Summary: This study investigates the effects of permafrost thaw on soil respiration and its components (autotrophic and heterotrophic) in the Tibetan Plateau. The results show that autotrophic respiration increases with thawing time, while heterotrophic respiration exhibits a hump-shaped pattern along the thaw sequence. The study also identifies factors such as plant traits, soil substrate quality, and microbial diversity that drive the changes in respiration components. These findings highlight the importance of considering permafrost carbon-climate feedback in Earth system models.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Geography, Physical
Alexander I. Kizyakov, Sebastian Wetterich, Frank Guenther, Thomas Opel, Loeka L. Jongejans, Jeremy Courtin, Hanno Meyer, Andrei G. Shepelev, Igor I. Syromyatnikov, Alexander N. Fedorov, Mikhail V. Zimin, Guido Grosse
Summary: Thaw slumps are clear indicators of permafrost degradation, and the Batagay megaslump is the largest known thaw slump on Earth. Research has shown that the morphology of thaw slumps is closely related to the structure and properties of permafrost.
Article
Geosciences, Multidisciplinary
Madison M. Douglas, Kieran B. J. Dunne, Michael P. Lamb
Summary: Climatic warming and permafrost thaw are expected to increase Arctic riverbank erosion, but current theory overpredicts the erosion rates. We developed a simple model that predicts more modest rates due to sediment-entrainment limitation and riverbank armoring by slump blocks. This study suggests that erosion rates may be less sensitive to warming than previously predicted.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Review
Geochemistry & Geophysics
Kun Zhao, Giovanni Coco, Zheng Gong, Stephen E. Darby, Stefano Lanzoni, Fan Xu, Kaili Zhang, Ian Townend
Summary: Bank retreat plays a fundamental role in fluvial and estuarine dynamics, affecting channel evolution, sediment supply, and habitat diversity. This review examines mechanisms, observations, and modeling of bank retreat in rivers and tidal channels. It finds that external forces have similar effects on bank stability and failure mode in both river and tidal environments. The review discusses existing data and modeling approaches, highlighting the need to consider hydraulic and geotechnical controls. It proposes a new hierarchy of modeling styles and emphasizes the importance of understanding multifactor-driven bank retreat at different temporal scales.
REVIEWS OF GEOPHYSICS
(2022)
Article
Environmental Sciences
Jing Tao, Qing Zhu, William J. Riley, Rebecca B. Neumann
Summary: Arctic warming has led to increased vegetation growth and soil respiration, with the most severe impacts during the cold season. An improved Earth system model is able to better capture the CO2 emissions over Arctic tundra. The rate of warm-season net CO2 uptake is increasing faster than that of cold-season emissions, potentially turning the Alaskan Arctic tundra into a net CO2 sink by 2100.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Ecology
Gesa Meyer, Elyn R. Humphreys, Joe R. Melton, Alex J. Cannon, Peter M. Lafleur
Summary: Climate change in the Arctic is causing shifts in vegetation communities and carbon fluxes, highlighting the importance of considering shrub plant functional types in models to accurately simulate energy and CO2 interactions. The revised model captures the impact of shrubs on energy and CO2 fluxes in Arctic tundra ecosystems, but still shows overestimation in certain areas.
Article
Environmental Sciences
Ana Khan, Becky A. Ball
Summary: The polar regions respond differently to climate change in terms of temperature and moisture. Soil microbes in polar deserts are co-limited by temperature and moisture, while the response in tundra ecosystems depends on the geographic location. Carbon and nitrogen cycles in polar regions are more sensitive to climate change, while phosphorus availability is not affected.
SCIENCE OF THE TOTAL ENVIRONMENT
(2024)
Article
Geosciences, Multidisciplinary
Jan Olaf Melchert, Philipp Wischhoefer, Christian Knoblauch, Tim Eckhardt, Susanne Liebner, Janet Rethemeyer
Summary: The release of greenhouse gases from permafrost deposits in the circumarctic regions may accelerate global warming, and this feedback is controlled by the microbial degradability of the organic matter and the release of inorganic carbon. The study found that the CO2 released from thawed Yedoma is mainly from Pleistocene-age organic matter, with a smaller contribution from modern organic substrate and inorganic carbon. Younger organic substrates in the freshly thawed Yedoma were preferentially degraded, while the contribution of inorganic carbon increased during incubation. The results indicate the importance of considering both organic and inorganic carbon sources when estimating CO2 fluxes from thawed permafrost.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Microbiology
Julia Mitzscherling, Joana MacLean, Daniel Lipus, Alexander Bartholomaus, Kai Mangelsdorf, Andre Lipski, Vladimir Roddatis, Susanne Liebner, Dirk Wagner
Summary: Strain NGK35T is a novel species within the genus Paenalcaligenes, which was isolated from plastic-polluted landfill soil and exhibits specific characteristics in various environmental conditions. It shows potential applications due to its motility and unique biological reactions.
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY
(2022)
Article
Microbiology
Julia Mitzscherling, Joana MacLean, Daniel Lipus, Alexander Bartholomaeus, Kai Mangelsdorf, Andre Lipski, Vladimir Roddatis, Susanne Liebner, Dirk Wagner
Summary: A novel hexadecane-degrading, non-motile, Gram-positive bacterium named Nocardioides alcanivorans sp. nov., was isolated from plastic polluted soil. It showed distinctive phenotypic and molecular characteristics compared to its phylogenetic neighbors.
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY
(2022)
Article
Microbiology
Tom Berben, Franco Forlano Bo, Michiel H. in 't Zandt, Sizhong Yang, Susanne Liebner, Cornelia U. Welte
Summary: This study analyzed sediment core genomes from Polar Fox Lagoon in Siberia and found that Bathyarchaeota in the lake mainly degrade peptides and have incomplete degradation pathways for plant-derived polymers. Methanogenesis and hydrogen metabolism were also found to be insufficient, leaving a significant gap in our understanding of their metabolism.
ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY
(2022)
Article
Biodiversity Conservation
Jessica G. Ernakovich, Robyn A. Barbato, Virginia I. Rich, Christina Schadel, Rebecca E. Hewitt, Stacey J. Doherty, Emily D. Whalen, Benjamin W. Abbott, Jiri Barta, Christina Biasi, Chris L. Chabot, Jenni Hultman, Christian Knoblauch, Maggie C. Y. Lau Vetter, Mary-Cathrine Leewis, Susanne Liebner, Rachel Mackelprang, Tullis C. Onstott, Andreas Richter, Ursel M. E. Schutte, Henri M. P. Siljanen, Neslihan Tas, Ina Timling, Tatiana A. Vishnivetskaya, Mark P. Waldrop, Matthias Winkel
Summary: The physical and chemical changes that occur during permafrost thaw have a direct impact on microbial communities, which in turn affect biogeochemistry and climate feedbacks. The proposed Assembly Theory framework provides a way to understand the changes in microbial communities and their implications for community function and climate feedbacks.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Multidisciplinary Sciences
Jens Strauss, Christina Biasi, Tina Sanders, Benjamin W. Abbott, Thomas Schneider von Deimling, Carolina Voigt, Matthias Winkel, Maija E. Marushchak, Dan Kou, Matthias Fuchs, Marcus A. Horn, Loeka L. Jongejans, Susanne Liebner, Jan Nitzbon, Lutz Schirrmeister, Katey Walter Anthony, Yuanhe Yang, Sebastian Zubrzycki, Sebastian Laboor, Claire Treat, Guido Grosse
Summary: Nitrogen plays a crucial role in regulating various aspects of the permafrost climate feedback, but its estimates are highly uncertain. This study provides new estimates of nitrogen stocks in the Yedoma domain, showing an increase of 46% compared to previous estimates for the entire permafrost zone. The large nitrogen pool stored in permafrost could have significant regional and global consequences if partially mobilized by thawing.
NATURE COMMUNICATIONS
(2022)
Article
Biology
Ebuka Canisius Nwosu, Achim Brauer, Marie-Eve Monchamp, Sylvia Pinkerneil, Alexander Bartholomaeus, Martin Theuerkauf, Jens-Peter Schmidt, Kathleen R. Stoof-Leichsenring, Theresa Wietelmann, Jerome Kaiser, Dirk Wagner, Susanne Liebner
Summary: Analysis of sedimentary DNA in a German lake reveals a spike in cyanobacteria abundance during the Bronze Age and the past century due to human activities. This high-resolution molecular analysis provides evidence that humans have been impacting lake ecology for millennia. Managing aquatic systems today requires awareness of the long-term legacy of human influence.
COMMUNICATIONS BIOLOGY
(2023)
Article
Biodiversity Conservation
Sizhong Yang, Sara E. Anthony, Maren Jenrich, Michiel H. in 't Zandt, Jens Strauss, Pier Paul Overduin, Guido Grosse, Michael Angelopoulos, Boris K. Biskaborn, Mikhail N. Grigoriev, Dirk Wagner, Christian Knoblauch, Andrea Jaeschke, Janet Rethemeyer, Jens Kallmeyer, Susanne Liebner
Summary: Thermokarst lagoons play an important role in the production and release of greenhouse gases. The infiltration of sulfate-rich marine water into thermokarst lagoons alters the geochemical characteristics and microbial methane-cycling community. Methane oxidation is higher in thermokarst lagoons, while methane-producing microorganisms are similar to lakes.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Ecology
Mark P. P. Waldrop, Christopher L. L. Chabot, Susanne Liebner, Stine Holm, Michael W. W. Snyder, Megan Dillon, Steven R. R. Dudgeon, Thomas A. A. Douglas, Mary-Cathrine Leewis, Katey M. M. Walter Anthony, Jack W. W. McFarland, Christopher D. D. Arp, Allen C. C. Bondurant, Neslihan Tas, Rachel Mackelprang
Summary: This study analyzed 133 permafrost metagenomes from North America, Europe, and Asia and found that permafrost microbial biodiversity and taxonomic distribution varied with pH, latitude, and soil depth. Energy metabolism and C-assimilation were among the strongest selective pressures shaping permafrost microbial communities, indicating the importance of energy acquisition and substrate availability. The spatial variation in metabolic potential could cause regional-to-global scale variation in C and nitrogen processing and greenhouse gas emissions as permafrost thaws due to climate change.
Article
Multidisciplinary Sciences
Guibiao Yang, Zhihu Zheng, Benjamin W. Abbott, David Olefeldt, Christian Knoblauch, Yutong Song, Luyao Kang, Shuqi Qin, Yunfeng Peng, Yuanhe Yang
Summary: This study provides insights into methane emissions from thermokarst lakes in high-altitude permafrost regions. The findings show that thermokarst lakes have high methane emissions during the ice-free period, with ebullition being the primary emission pathway. The study also highlights the importance of methanogenic genes in regulating methane fluxes.
NATURE COMMUNICATIONS
(2023)
Article
Environmental Sciences
Leonardo de A. Galera, Tim Eckhardt, Christian Beer, Eva-Maria Pfeiffer, Christian Knoblauch
Summary: Arctic warming leads to permafrost thaw and accelerates the decomposition of soil organic matter, resulting in the release of CO2 and CH4. This study quantified the ratios of CO2:CH4 from decomposition in wet and dry tundra soils using in situ measurements. The CO2:CH4 ratios decreased sharply in the water-saturated site, with a median of 12.2 over the vegetation period. Factors such as active layer depth and soil temperature played a significant role in controlling these ratios. The study provides insights into the dynamic nature of CO2:CH4 ratios and will help improve future simulations of greenhouse gas fluxes.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Review
Environmental Studies
Alexander I. Kizyakov, Alexander A. Ermolov, Alisa V. Baranskaya, Mikhail N. Grigoriev
Summary: The Laptev Sea coast is characterized by a unique high-latitude and dynamic landscape. The presence of low-temperature permafrost and high ice content results in various permafrost landforms and features. Coastal retreat is significantly influenced by thermal abrasion and thermal denudation. Geological structure and sea hydrodynamic conditions contribute to the diversity of this sea coast's types. A morphodynamic classification and segmentation of the Laptev Sea coast was conducted, considering the leading relief-forming processes in this coastal zone. The presented classification can be widely applied in the eastern Arctic seas of Eurasia, serving as a foundation for future scientific and applied research.
Article
Ecology
Cordula Nina Gutekunst, Susanne Liebner, Anna-Kathrina Jenner, Klaus-Holger Knorr, Viktoria Unger, Franziska Koebsch, Erwin Don Racasa, Sizhong Yang, Michael Ernst Boettcher, Manon Janssen, Jens Kallmeyer, Denise Otto, Iris Schmiedinger, Lucas Winski, Gerald Jurasinski
Summary: This study investigated the effects of brackish water inflow on microbial communities and methane production-consumption dynamics in a freshwater rewetted fen. The results showed that the brackish water inflow and preceding drought increased sulfate availability but did not hinder methane production or increase methane consumption. Methane oxidation may occur in the water column or organic litter on the ground.