macreadie-netdrawdown-2022.pdf (6.87 MB)
Net Drawdown of Greenhouse Gases (CO2, CH4 and N2O) by a Temperate Australian Seagrass Meadow
journal contribution
posted on 2022-01-01, 00:00 authored by Q R Ollivier, D T Maher, C Pitfield, Peter MacreadiePeter MacreadieSeagrasses have some of the highest rates of carbon burial on the planet and have therefore been highlighted as ecosystems for nature-based climate change mitigation. However, information is still needed on the net radiative forcing benefit of seagrasses inclusive of their associated greenhouse gas (GHG) emissions. Here, we report simultaneous estimates of seagrass-associated carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) air–water emissions. Applying in situ sampling within a south-east Australian seagrass ecosystem, this study finds atmospheric GHG emissions from waters above seagrasses to range from − 480 ± 15.96 to − 16.2 ± 8.32 mg CO2-equivalents m2 d−1 (net uptake), with large temporal and spatial variability. Using a combination of gas specific mass balance equations, dissolved stable carbon isotope values (δ13C) and in situ time-series data, CO2-e flux is estimated at − 21.74 mg m2 d−1. We find that the net release of CH4 (0.44 µmol m2 h−1) and net uptake of N2O (− 0.06 µmol m2 h−1) effectively negated each other at 16.12 and − 16.13 mg CO2-e m2 d−1, respectively. The results of this study indicate that temperate Australian seagrasses may function as net sinks of atmospheric CO2-e. These results contribute towards filling key emission accounting gaps both in the Australian region, and through the simultaneous measurement of the three key greenhouse gas species.
History
Journal
Estuaries and CoastsPublisher DOI
Link to full text
ISSN
1559-2723eISSN
1559-2731Publication classification
C1 Refereed article in a scholarly journalUsage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC