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Updated: Jul 13, 2025
09:38
Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
Published on: January 7, 2019
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Quantifying Stochastic Processes in Shaping Dissolved Organic Matter Pool with High-Resolution Mass Spectrometry
Zhixiang She1,2,3, Jin Wang1,2,3, Shu Wang1,2,3
1School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, Anhui, China.
Environmental Science & Technology
|October 16, 2023
Summary
This study introduces a neutral theory for dissolved organic matter (DOM) dynamics, revealing that random processes significantly shape molecular composition in aquatic ecosystems. Understanding this stochasticity is key for accurate carbon cycling predictions.
Area of Science:
- Environmental Chemistry
- Aquatic Ecology
- Theoretical Ecology
Background:
- Natural dissolved organic matter (DOM) is a complex molecular mixture, crucial for carbon cycling.
- Current understanding of DOM molecular dynamics, particularly stochastic processes, is limited, hindering accurate carbon cycle predictions.
Purpose of the Study:
- To introduce a neutral theory based on ecological principles to explain DOM molecular generation, degradation, and migration.
- To develop and validate a neutral model for assessing DOM molecular probability distributions.
Main Methods:
- Formulated a neutral model predicting a beta-distribution for DOM molecular frequencies and abundances.
- Validated the model using high-resolution mass spectrometry (HRMS) data from diverse aquatic environments (lakes, rivers, seas).
- Applied an ecological null model to analyze deviations from neutral expectations in experimental settings (photodegradation, microbial activity).
Main Results:
- The neutral model fitting confirmed the prevalence of neutral molecular distribution in natural DOM pools.
- Quantified the significant role of stochasticity in DOM molecular dynamics across various waterbodies.
- Identified nonrandom molecular transformations in photochemical and microbial experiments, deviating from neutral predictions.
- Demonstrated that photodegradation decreases molecular stochasticity, while river surface conditions show intensified random distribution compared to porewater.
Conclusions:
- Stochastic processes are fundamental in shaping natural dissolved organic matter pools.
- The developed DOM molecular neutral model provides a theoretical framework for understanding DOM dynamics in aquatic and other ecosystems.
- This work highlights the importance of considering neutral theory for predicting carbon cycling.
- Deviations from neutral models in experiments reveal specific nonrandom transformation pathways in DOM.
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