Assessing methane emissions and soil carbon stocks in the Camargue coastal wetlands: Management implications for climate change regulation
Author
Masqué, Pere
Lafratta, Anna
Lavery, Paul
Hilaire, Samuel
Thomas, Cyrille
Boisnard, Arnaud
Martínez-Espinosa, Columba
Grillas, Patrick
Publication date
2024-08-03ISSN
0048-9697
Abstract
Coastal wetlands are crucial in climate change regulation due to their capacity to act as either sinks or sources of carbon, resulting from the balance between greenhouse gas (GHG) emissions, mainly methane (CH4), and soil carbon sequestration. Despite the paramount role of wetlands in climate regulation few studies investigate both aspects. The Camargue is one of the largest wetlands in Europe, yet the ways in which environmental and anthropic factors drive carbon dynamics remain poorly studied. We examined GHG emissions and soil organic carbon (SOC) stocks and accumulation rates in twelve representative wetlands, including two rice fields, to gain insights into the carbon dynamics and how it is influenced by hydrology and salinity. Mean CH4 rates ranged between – 87.0 and 131.0 mg m−2 h−1and the main drivers were water conductivity and redox, water table depth and soil temperature. High emission rates were restricted to freshwater conditions during summer flooding periods whereas they were low in wetlands subjected to summer drought and water conductivity higher than 10 mS cm−1. Nitrous oxide emissions were low, ranging from – 0.5 to 0.9 mg N2O m−2 h−1. The SOC stocks in the upper meter ranged from 17 to 90 Mg OC ha−1. Our research highlights the critical role of low-saline wetlands in carbon budgeting which potentially are large sources of CH4 but also contain the largest SOC stocks in the Camargue. Natural hydroperiods, involving summer drought, can maintain them as carbon sinks, but altered hydrology can transform them into sources. Artificial freshwater supply during summer leads to substantial CH4 emissions, offsetting their SOC accumulation rates. In conclusion, we advocate for readjusting the altered hydrology in marshes and for the search of management compromises to ensure the compatibility of economic and leisure activities with the preservation of the inherent climate-regulating capacity of coastal wetlands.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
574 - General ecology and biodiversity
Pages
12
Publisher
Elsevier
Is part of
Science of the Total Environment
Citation
Martínez-Eixarch, Maite, Pere Masqué, Anna Lafratta, Paul Lavery, Samuel Hilaire, Lluís Jornet, Cyrille Thomas, et al. 2024. “Assessing Methane Emissions and Soil Carbon Stocks in the Camargue Coastal Wetlands: Management Implications for Climate Change Regulation.” The Science of the Total Environment 950: 175224. https://doi.org/10.1016/j.scitotenv.2024.175224.
Program
Aigües Marines i Continentals
Cultius Extensius Sostenibles
This item appears in the following Collection(s)
- ARTICLES CIENTÍFICS [2850]
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc/4.0/