The influence of salt on dissolved organic matter from peat soils
| Autor: | Robert Strehse, Peter Leinweber, Heike Bohne, Yosef Amha |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Peat Soil organic matter Salt (chemistry) 04 agricultural and veterinary sciences 010501 environmental sciences 01 natural sciences Decomposition chemistry.chemical_compound chemistry Geochemistry and Petrology Environmental chemistry Dissolved organic carbon 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Lignin Organic matter Saltwater intrusion 0105 earth and related environmental sciences |
| Zdroj: | Organic Geochemistry. 125:270-276 |
| ISSN: | 0146-6380 |
| DOI: | 10.1016/j.orggeochem.2018.10.001 |
| Popis: | Understanding the influence of salt on the release and transformations of dissolved organic matter (DOM) is crucial for developing management strategies for coastal wetlands. We hypothesize that salt causes distinct changes in certain compound classes of DOM, distinguishable from the impact of other factors such as peat origin and decomposition degree. Therefore, the DOM composition was investigated in freshwater and saltwater extracts of nine peat samples of varying origin and decomposition degree. Samples were analyzed for carbon and nitrogen concentrations and pH values, and organic matter composition by temperature-resolved pyrolysis-field ionization mass spectrometry (Py-FIMS). The data revealed larger abundances of phenols/lignin monomers, peptides, carbohydrates, (mainly heterocyclic) N-compounds/nitriles and alkylaromatics in the saltwater extracts. The thermal release curves in Py-FIMS indicated a precipitation of fractions of alkylaromatics, N-compounds/nitriles and phenols/lignin monomers and a release of lipids, alkylaromatics and free fatty acids n-C16 to n-C34 in the saltwater extracts. Coagulation/precipitation, cation exchange and, for free fatty acids, the formation of micelles seem to be key mechanisms of the salt impact. Due to the stronger direct and indirect influences of saltwater on less decomposed peat an adapted management should be directed to preferentially protect rather pristine peatlands from saltwater intrusions that can be expected as a result of rising ocean levels under climate change. |
| Databáze: | OpenAIRE |
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