التفاصيل البيبلوغرافية
العنوان: |
Atmospheric CO2 exchanges measured by Eddy Covariance over a temperate salt marsh and influence of environmental controlling factors. |
المؤلفون: |
Mayen, Jérémy, Polsenaere, Pierre, Lamaud, Éric, Arnaud, Marie, Kostyrka, Pierre, Bonnefond, Jean-Marc, Geairon, Philippe, Gernigon, Julien, Chassagne, Romain, Lacoue-Labarthe, Thomas, Regaudie de Gioux, Aurore, Souchu, Philippe |
المصدر: |
Biogeosciences Discussions; 7/20/2023, p1-40, 40p |
مصطلحات موضوعية: |
SALT marshes, ATMOSPHERIC carbon dioxide, COASTS, SPRING, EDDIES, GROWING season, LOW temperatures |
مستخلص: |
Within the coastal zone, salt marshes are atmospheric CO2 sinks and represent an essential component of biological carbon (C) stored on Earth due to a strong primary production. Significant amounts of C are processed within these tidal systems which requires a better understanding of the temporal CO2 flux dynamics, the metabolic processes involved and the controlling factors. Within a temperate salt marsh (French Atlantic coast), continuous CO2 exchange measurements were performed by the atmospheric eddy covariance technique to assess the net ecosystem exchange (NEE) at diurnal, tidal and seasonal scales and the associated relevant biophysical drivers. During emersion, NEE fluxes were partitioned into net ecosystem production (NEP), gross primary production (GPP) and ecosystem respiration (Reco) to study marsh metabolic processes. Over the year 2020, the measured net C balance was -483 g C m-2 yr-1 while GPP and Reco absorbed and emitted 1019 and 533 g C m-2 yr-1, respectively. The highest CO2 uptake was recorded in spring during the growing season for halophyte plants in relationships with favourable environmental conditions for photosynthesis whereas in summer, higher temperatures and lower humidity rates increased ecosystem respiration. At the diurnal scale, the salt marsh was a CO2 sink during daytime, mainly driven by light, and a CO2 source during night-time, mainly driven by temperature, irrespective of emersion or immersion periods. However, daytime immersion strongly affected NEE at the daily scale by reducing marsh CO2 uptake up to 90%. During night-time immersion, CO2 emissions could be completely suppressed, even causing a change in metabolic status from source to sink under certain situations, especially in winter when Reco rates were lowest. At the annual scale, tidal rhythm did not significantly affect the net C balance of the studied salt marsh since similar annual values of measured NEE and estimated NEP were recorded. [ABSTRACT FROM AUTHOR] |
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قاعدة البيانات: |
Complementary Index |