Sub-tropical seagrass ecosystem metabolism measured by eddy covariance
Long, Matthew H.
McGlathery, Karen J.
Zieman, Joseph C.
MetadataShow full item record
The metabolism of seagrass ecosystems was examined at 4 sites in south Florida, USA, using the eddy covariance technique under in situ conditions. Three sites were located across a phosphorus-driven productivity gradient to examine the combined effects of dynamic variables (irradiance, flow velocity) and state variables (sediment phosphorus and organic content, seagrass biomass) on ecosystem metabolism and trophic status. Gross primary production and respiration rates varied significantly across Florida Bay in the summer of 2012 with the lowest rates (64 and –53 mmol O2 m–2 d–1, respectively) in low-phosphorus sediments in the northeast and the highest (287 and –212 mmol O2 m–2 d–1, respectively) in the southwest where sediment phosphorus, organic matter, and seagrass biomass are higher. Seagrass ecosystems offshore of the Florida Keys had similar large daily production and respiration rates (397 and –17 mmol O2 m–2 d–1, respectively) and were influenced by flow through the permeable offshore sediments. Across all sites, net ecosystem metabolism rates indicated that the seagrass ecosystems were autotrophic in the summertime. Substantial day-to-day variability in metabolic rates was found due to variations in irradiance and flow velocity. At all sites the relationship between photosynthesis and irradiance was linear and did not show any sign of saturation over the entire irradiance range (up to 1400 µmol photons m–2 s–1). This was likely due to the efficient use of light by the large photosynthetic surface area of the seagrass canopy, an effect which can only be examined by in situ measurements that integrate across all autotrophs in the seagrass ecosystem.
Author Posting. © Inter-Research, 2015. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 529 (2015): 75-90, doi:10.3354/meps11314.
Suggested CitationArticle: Long, Matthew H., Berg, Peter, McGlathery, Karen J., Zieman, Joseph C., "Sub-tropical seagrass ecosystem metabolism measured by eddy covariance", Marine Ecology Progress Series 529 (2015): 75-90, DOI:10.3354/meps11314, https://hdl.handle.net/1912/7374
Showing items related by title, author, creator and subject.
Seagrass metabolism across a productivity gradient using the eddy covariance, Eulerian control volume, and biomass addition techniques Long, Matthew H.; Berg, Peter; Falter, James L. (John Wiley & Sons, 2015-05-22)The net ecosystem metabolism of the seagrass Thalassia testudinum was studied across a nutrient and productivity gradient in Florida Bay, Florida, using the Eulerian control volume, eddy covariance, and biomass addition ...
McMahon, Kelton W.; Berumen, Michael L.; Thorrold, Simon R. (2012-06)Tropical marine ecosystems are under mounting anthropogenic pressure from overfishing and habitat destruction, leading to declines in their structure and function on a global scale. While maintaining connectivity among ...
Seagrass impact on sediment exchange between tidal flats and salt marsh, and the sediment budget of shallow bays Donatelli, Carmine; Ganju, Neil K.; Fagherazzi, Sergio; Leonardi, Nicoletta (John Wiley & Sons, 2018-05-20)Seagrasses are marine flowering plants that strongly impact their physical and biological surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience ...