Mangrove forests have one of the highest capacities of any ecosystem to sequester carbon. Mangroves in the Red Sea exist in a uniquely saline, high temperature, nutrient limited environment and the effects on carbon storage and greenhouse gas (GHG) emissions from arid mangrove soils is understudied. The flux of carbon dioxide (CO2) and methane (CH4) has the potential to enhance or reduce the carbon storage capacity of mangroves, which is an important nature-based solution for carbon drawdown to limit global warming. To determine the magnitude of CO2 and CH4 flux from mangrove soil in the Red Sea, soil cores were incubated on a monthly basis for over a year in light and dark conditions. Soil properties such as salinity, organic carbon, water content, bulk density, and stable isotopes, along with environmental variables such as inundation frequency and temperature were measured to resolve the drivers and variation of GHG flux over time. Additionally, 16S and 18S rRNA metabarcoding was conducted to determine the relative influence of prokaryotes and eukaryotes in the microbial mat within this mangrove ecosystem, and the microbial contribution to GHG flux. Oxygen microsensors were used for fine-scale resolution of the microbial mat, to determine photosynthetic rates and oxygen profiles. Fluxes were found to be highly variable, with the highest correlation between GHG flux and soil water content (p<0.05). Both prokaryotic and eukaryotic components of the microbial mat had a significant relationship with GHG flux, with mixed impacts depending on the taxa. These findings show that Red Sea mangroves, despite their lower carbon storage capacity, are a negligible source of GHG to the atmosphere unlike other regions where GHG emissions offset a greater proportion of carbon storage potential. Additionally, the importance of the microbial mat in this ecosystem is demonstrated, and an important consideration for future studies on mangroves and their potential as a nature-based solution against global warming.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/691417 |
| Date | 04 1900 |
| Creators | Breavington, Jessica |
| Contributors | Duarte, Carlos M., Biological and Environmental Science and Engineering (BESE) Division, Rosado, Alexandre S., Daffonchio, Daniele |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | 2024-05-03, At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis will become available to the public after the expiration of the embargo on 2024-05-03. |
| Relation | N/A |
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