Patterns and determinants of plant‐derived lignin phenols in coastal wetlands: Implications for organic C accumulation

Functional Ecology, Год журнала: 2023, Номер 37(4), С. 1067 - 1081

Опубликована: Фев. 6, 2023

Abstract As a major plant‐derived soil organic carbon (SOC) component, lignin phenols are unique biomarkers that reflect biogeochemical characteristics under different vegetation compositions and climatic zones in coastal wetlands. However, the latitudinal patterns of to SOC their link with stability controlling mechanisms remain poorly understood. A total 156 samples from 39 sites along 5000 km transect, were taken explore effects biological environmental controls on phenols. Lignin had contents ranging 1.91 83.3 mg g −1 OC, positive correlation was detected grass‐dominated salt marsh, but weakly negative mangrove. Positive correlations between or content C/V S/V (the cinnamyl‐ syringyl‐to‐vanillyl) ratios found, while overall (Ad/Al) V S acid‐to‐aldehyde vanillyl syringyl units) detected, respectively, which confirmed validity these biomarker degradation parameters. Our findings revealed plant C inputs monomer directly influenced capacity soils. stabilization mainly controlled by properties (i.e. pH, EC sand/clay). Mean annual temperature (MAT) both increasing decomposition indirectly changing biogeochemistry microbial substrate availability). Coastal wetlands characterized high primary productivity burial rate, yet not as much we thought compared residues C. Precise identification quantification origin, decomposition, determinants help us understand contribution sequestration its response climate changes. Read free Plain Language Summary for this article Journal blog.

Язык: Английский

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Experiment on Sediment Ammonia Nitrogen Release of Chaohu Lake in Varying Hydrodynamic Disturbance

Sustainability, Год журнала: 2023, Номер 15(2), С. 1581 - 1581

Опубликована: Янв. 13, 2023

Shallow water has low depth, and hydrodynamic conditions may change with the effect of wind waves, resulting in sediment suspension pollutant release. To investigate influence incipient motion on ammonia nitrogen (NH3-N) release shallow lakes under disturbance, we monitored concentration overlying sediments Chaohu Lake static, weak, strong disturbance analyzed rate based these concentrations. In static condition, particles surface moved individually (individual movement), was 9.59 mg/m2/day. When weak a small proportion started to move (small increased 34.21 further strengthened, most (general 77.04 Distribution showed that varied western area followed by eastern area, central had lowest rate. The daily ranged from 8742.3 kg 61,008.59 kg. this experiment, combined movement release, which provides new reference for study management other lakes.

Язык: Английский

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Turbulence burst events in the bottom boundary layer of a tidal river

Physics of Fluids, Год журнала: 2025, Номер 37(1)

Опубликована: Янв. 1, 2025

Understanding flow turbulence dynamics in tidal river systems is critical for nutrient transport, sediment dynamics, and ecosystem health nature. This study investigates the characteristics of turbulent burst events within bottom boundary layer a river, utilizing on site observational data applying variational mode decomposition (VMD) local intermittency detection (LIM). The results reveal that VMD–LIM method effective examining multi-scale processes. Key findings indicate positive correlation between eddy structures velocity, with fully developed frequent observed during strong currents, contrasting weak current periods. Distinct event types emerge across different frequencies, categorized as “turtle type” (lower intensity, longer duration) at low frequencies “rabbit [higher shorter duration, order O(100) Hz] high [on O(101) Hz]. Energy transfer predominantly occurs adjacent intrinsic functions (IMFs), more transfers highlighting active energy cascade process rivers compared to estuarine environments. emphasizes need further exploration effects varying scales Reynolds stress dynamics. By elucidating relationship conditions, we aim provide valuable insight predicting impacts aquatic environments, furtherly improving models transport enhancing ecological ecosystems.

Язык: Английский

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Wave-current interaction on turbulence mixing and sediment resuspension in muddy tidal flats

Estuarine Coastal and Shelf Science, Год журнала: 2025, Номер unknown, С. 109141 - 109141

Опубликована: Янв. 1, 2025

Язык: Английский

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The near-bottom turbulence induced resuspension of seabed material in deep sea

Deep Sea Research Part I Oceanographic Research Papers, Год журнала: 2025, Номер unknown, С. 104491 - 104491

Опубликована: Март 1, 2025

Язык: Английский

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Probabilistic Characterization of Sweep and Ejection Events in Turbulent Flows and Its Implications on Sediment Transport

Water Resources Research, Год журнала: 2022, Номер 58(5)

Опубликована: Март 29, 2022

Abstract Turbulent boundary layers are populated by a hierarchy of recurrent structures normally referred to as “coherent structures.” Among others, ejection and sweep events critical coherent responsible for sediment transport. This study focuses on gaining better understanding the spatial‐–temporal probabilistic characteristics events. The existence uniform momentum zones (UMZs) is demonstrated affect spatial distribution large‐scale motions (LSMs), tend present near UMZ edges where interfacial high shears exist. In this study, detection employed identify structures. conditional velocity decomposition then applied available direct numerical simulation (DNS) flow data after were determined. Based integrated criterion distinguishing events, one can determine such center point, wall‐normal length, streamwise length. Physical insights joint probability density functions length be established. attached detached features sweeps ejections classified characterized, respectively. Durations follow lognormal in study. occurrence ratio (LSMs) quantified from DNS data. implications results transport discussed. contributions with respect height intermittency geometrical properties presented.

Язык: Английский

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Modified stochastic diffusion particle tracking model driven by skew Brownian motion: Analysis of sediment particle motion in turbulent flow under the effects of ejection and sweep

Chaos An Interdisciplinary Journal of Nonlinear Science, Год журнала: 2024, Номер 34(3)

Опубликована: Март 1, 2024

Turbulent bursting events have been classified into outward interactions (Q1), ejections (Q2), inward (Q3), and sweeps (Q4) in various studies. Ejections (Q2) identified as significant contributors to time consumption, momentum flux, sediment flux. Additionally, research has shown that the distribution of these varies nonuniformly at different bed elevations. Despite extensive investigations nonuniform turbulent events, their impact on transport rarely explored. In this work, we developed a modified stochastic diffusion particle tracking model (SD-PTM) driven by skew Brownian motion (SBM) using Lagrangian approach scrutinize movement flows. The incorporates characteristics derived from direct numerical simulation dataset, allowing for comprehensive analysis dynamics. Moreover, proposed accounts spatial ejection sweep well direction during events. Numerical simulations were conducted trace trajectories streamwise vertical directions. involved calculating variance examine anomalous diffusion. model's performance was evaluated comparing it with flow velocity concentration profiles obtained measurements previous conclusion, our study suggests particles can be thoroughly investigated under extreme conditions SD-PTM SBM.

Язык: Английский

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Turbulence Intermittency Effects on the Initiation Threshold of Sediment Motion in Natural Waters

Water Resources Research, Год журнала: 2024, Номер 60(5)

Опубликована: Май 1, 2024

Abstract The initiation threshold of sediment motion, a key component in quantifying transport, has potential link to intermittent turbulence bursts. Here, we elaborated situ experiments on coastal sea bottom covered with cohesive sediments, obtain intermittency parameters. variable “waiting time” between bursts was utilized capture the occurrence events natural waters. A relationship waiting time and shear stress reveals different features flux series before after reaching threshold, which can be used determine motion. Multi‐site results demonstrate limitations traditional empirical formulae for fine‐grained where cohesiveness becomes more pronounced as grain size decreases deviation reach 600%. formula modified using size, calculations were good agreement observed values, will greatly assist transport geomorphology model predictions.

Язык: Английский

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Modeling memory-enhanced stochastic suspended sediment transport with fractional Brownian motion in time-persistent turbulent flow

Stochastic Environmental Research and Risk Assessment, Год журнала: 2024, Номер 38(11), С. 4555 - 4575

Опубликована: Окт. 15, 2024

Язык: Английский

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The spatio-temporal distribution and transport of suspended sediment in Laizhou Bay: Insights from hydrological and sedimentological investigations

Frontiers in Earth Science, Год журнала: 2022, Номер 10

Опубликована: Сен. 20, 2022

Suspended sediment transport and deposition are crucial physical processes controlling the geomorphological evolution of estuaries bays. Specially, under context worldwide coastal erosion, knowledge spatio-temporal distribution suspended concentration (SSC) its associated load have become increasingly important for bay management. However, our understanding mechanisms dynamics continues to be hampered by lack high-resolution observations. Here, we present a study factors over Laizhou Bay. For this, conducted continuous measurements SSC, salinity, temperature, flow velocity at nine stations throughout Bay one 25-h period during each spring moderate tides. Based on these data, residual current, gradient Richardson numbers, flux were calculated. Our results indicate that strong current field occurs near Yellow River mouth, corresponding zone with high SSC. The overall diffusion characteristics controlled tidal field. Furthermore, findings suggest different degrees stratification occur in water column, which inhibit effective vertical sediment; Higher temperature was main cause stronger column tide than tide. Finally, reveal type seabed is an factor SSC influencing resuspension flux. We conclude primary advection pumping, especially advection. research provides both foundational reference source-to-sink process from sea, as well guideline implications engineering construction channel dredging.

Язык: Английский

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