Video Experimental Relacionado

Updated: Feb 28, 2026

Monitoring Pedogenic Inorganic Carbon Accumulation Due to Weathering of Amended Silicate Minerals in Agricultural Soils.

Monitoring Pedogenic Inorganic Carbon Accumulation Due to Weathering of Amended Silicate Minerals in Agricultural Soils.

Published on: June 4, 2021

Secuestro de carbono en sedimentos restringido por la contaminación difusa agrícola: Evidencia de la materia orgánica

Kaiyue Ji¹, Wei Ouyang², Xinyi Liu¹

¹State Key Laboratory of Regional Environment and Sustainability, School of Environment, Beijing Normal University, Beijing 100875,China.

|February 25, 2026

Abstract:

Sediment dissolved organic matter (DOM) in river-lake transitional zones mediates nutrient, carbon, and contaminant cycling, yet the roles of anthropogenic and natural inputs in shaping vertical sediment composition and inferred carbon stabilization remain poorly understood. Here, we conducted a vertical profiling analysis of river-lake ecotone sediments in Poyang Lake by integrating physicochemical, spectroscopic, isotopic and modelling approaches within a dual-level end-member mixing analysis (EMMA) framework. The sediments were primarily composed of sand (44.7%) and silt (35.8%) and exhibited weak acidity, with phosphorus pollution (S_TP 0.57-2.97) exceeding nitrogen (S_TN 0.07-1.45), particularly in the inflowing rivers. Stable isotope-based EMMA applied to bulk sediment organic matter (SOM) revealed mixed source contributions dominated by fertilizer inputs, based on δ¹³C (-25.58‰ to -20.53‰) and δ¹⁵N (3.99‰ to 5.98‰) signatures. Subsequently, fluorescence-based EMMA identified livestock and poultry (57%), riparian vegetation (23%), and farmland leaching (9%) as the main contributors to sediment water-extractable organic matter (WEOM). LightGBM-SHAP analysis showed α₂₅₄ was strongly associated with optically inferred stability of WEOM, with distinct controls between surface and deep sediments. Overall, the dual-level EMMA analysis indicated that agricultural diffuse pollution enhanced the WEOM lability and constrained the sediment carbon sequestration potential in river-lake transitional zones. Interpretations derived from fluorescence-based EMMA for sediments may be affected by DOM transformation during sediment burial and by uncertainties associated with end-member representativeness. These findings underscore the necessity of integrated nutrient management and land-use practices to sustain carbon storage in large floodplain lake systems.

Palabras clave:

Contaminación difusa Materia orgánica disuelta Espectroscopía de fluorescencia Zona de transición río-lago Asignación de fuentes

Más Videos Relacionados

Measuring and Mapping Patterns of Soil Erosion and Deposition Related to Soil Carbonate Concentrations Under Agricultural Management

Measuring and Mapping Patterns of Soil Erosion and Deposition Related to Soil Carbonate Concentrations Under Agricultural Management

Published on: September 12, 2017

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

Measuring Carbon-based Contaminant Mineralization Using Combined CO2 Flux and Radiocarbon Analyses

Published on: October 21, 2016

Videos de Conceptos Relacionados

The Carbon Cycle

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.

Inorganic Nitrogen Assimilation

Inorganic Nitrogen Assimilation

Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...

Carbon-dioxide Fixation

Carbon-dioxide Fixation

Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...

Bioremediation

Bioremediation

Bioremediation is the use of prokaryotes, fungi, or plants to remove pollutants from the environment. This process has been used to remove harmful toxins in groundwater as a byproduct of agricultural run-off and also to clean up oil spills.

The Calvin Benson Cycle

The Calvin Benson Cycle

Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...