Reservoirs located in middle and high latitudes freeze for months in winter, where the accumulation characteristics of pollutants are changed by superimposed influence of salt exclusion from ice on the surface and pollution release from sediments at the bottom. Taking total nitrogen (TN) of Biliuhe reservoir in Northeast China as an example, we developed a model to simulate TN accumulation characteristics influenced by ice and sediments during the freezing period (NACISF), and quantified contributions of TN from ice and sediments. Model parameters of ice and sediments were determined by laboratory freeze-up simulation experiment and sediment release flux simulation experiment, and water quality data were obtained from field investigations. Results showed that the annual average amount of TN input during the ice-covered period from 2015 to 2020 was 220.77 t, the output was 400.11 t, and the accumulated amount was 589.52 t. TN excluded from ice and released from sediments contributed 8.12% and 7.17% of the total TN inputs in winter, respectively. Analysis showed that the TN excluded from ice was positively correlated with ice thickness and initial TN concentration. The maximum ice thickness of Biliuhe reservoir had a 13 year cyclic feature, and the proportion of TN excluded from ice to the total TN inputs in different periods ranged from 10.68% to 17.30% (mean 13.18%). Meanwhile, TN accumulated seasonally as summer > autumn > winter > spring. The TN exclusion effect in 2050 would be weakened when considering the combined effects of climate change and human activities, with a reduction of about 40.85% compared to the current. It is concluded that the NACISF model took into account the influences of both ice and sediments, which provided a detailed understanding of the accumulation characteristics of TN during freezing period, and had important reference significance for water quality management in winter.
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http://dx.doi.org/10.1016/j.envpol.2022.120025 | DOI Listing |
Nat Commun
January 2025
Centre for Marine Magnetism (CM2, Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
Under sustained global warming, Arctic climate is projected to become more responsive to changes in North Pacific meridional heat transport as a result of teleconnections between low and high latitudes, but the underlying mechanisms remain poorly understood. Here, we reconstruct subarctic humidity changes over the past 400 kyr to investigate the role of low-to-high latitude interactions in regulating Arctic hydroclimate. Our reconstruction is based on precipitation-driven sediment input variations in the Subarctic North Pacific (SANP), which reveal a strong precessional cycle in subarctic humidity under the relatively low eccentricity variations that dominated the past four glacial-interglacial cycles.
View Article and Find Full Text PDFNat Commun
January 2025
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Polar Terrestrial Environmental Systems, 14473, Potsdam, Germany.
A nearly ubiquitous negative relationship between taxonomic richness and mean range-size (average area of taxa) is observed across space. However, the complexity of the mechanism limits its applicability for conservation or range prediction. We explore whether the relationship holds over time, and whether plant speciation, environmental heterogeneity, or plant interactions are major factors of the relationship within northeast Siberia and Alaska.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Geology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland.
Massive injection of C depleted carbon to the ocean and atmosphere coincided with major environmental upheaval multiple times in the geological record. For several events, the source of carbon has been attributed to explosive venting of gas produced when magmatic sills intruded organic-rich sediment. The concept mostly derives from studies of a few ancient sedimentary basins with numerous hydrothermal vent complexes (HTVCs) where craters appear to have formed across large areas of the seafloor at the same time, but good examples remain rare in strata younger than the Early Eocene.
View Article and Find Full Text PDFEnviron Res
January 2025
College of Energy and Environment, Inner Mongolia University of Science and Technology,Baotou, 014010, PR China; Collaborative Innovation Center of Autonomous Region for Ecological Protection and Comprehensive Utilization in the Inner Mongolia Section of the Yellow River Basin, Baotou, 014010, PR China. Electronic address:
The coexistence of different microbial communities is fundamental to the sustainability of many ecosystems, yet our understanding of the relationships among microbial communities in plateau cold-region lakes affected by seasonal ice cover remains limited. This research involved investigating three lakes in the Inner Mongolia segment of the Yellow River basin during frozen and unfrozen periods in two habitats: water bodies and sediments. The research examined the composition and function of bacteria, archaea, and fungi across different times and habitats within the basin, their response to environmental variables in water and sediment, and inter-domain interactions between bacteria-archaea and bacteria-fungi were compared using interdomain ecological network (IDEN).
View Article and Find Full Text PDFPLoS One
January 2025
Departamento de Química, Laboratorio de Química Aplicada y Sustentable (LabQAS), Universidad del Bío-Bío, Concepción, Chile.
Ice-free areas are habitats for most of Antarctica's terrestrial biodiversity. Although fungal communities are an important element of these habitats, knowledge of their assemblages and ecological functions is still limited. Herein, we investigated the diversity, composition, and ecological functionality of fungal communities inhabiting sediments from ice-free areas across pristine and anthropogenically impacted sites in the Fildes Peninsula on King George Island, Antarctica.
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