Comparison of marine macrophytes for their contributions to blue carbon sequestration

• DOI: 10.1890/15-0149.1
• Publication Date: 2015-05-11T19:52:58Z
• Authors: Stacey M. Trevath...; Jeffrey Kelleway; Peter I. Macreadie; John Beardall; Peter Ralph; Alecia Bellgrove
• Keywords: Blue carbon; Vascular plant; Carbon fibers; Marine habitats

Many marine ecosystems have the capacity for long-term storage of organic carbon (C) in what are termed "blue carbon" systems. While blue systems (saltmarsh, mangrove, and seagrass) efficient at sequestration (C), much their sequestered C may originate from other (allochthonous) habitats. Macroalgae, due to high rates production, fragmentation, ability be transported, would also appear able make a significant contribution as donors In order assess stability macroalgal tissues likely pools C, we applied thermogravimetric analysis (TGA) 14 taxa macroalgae coastal vascular plants. We assessed structural complexity multiple lineages plant tissue types with differing cell wall structures found that decomposition dynamics varied significantly according differences structure composition among taxonomic groups function (photosynthetic vs. attachment). Vascular generally exhibited greater proportion mass loss temperatures > 300 degrees (peak -320 C) than between 175-300 C), consistent lignocellulose matrix Greater variation signatures within taxa, relative plants, was diversity groups. Significant degradation above 600 some macroalgae, well belowground seagrass tissues, is presence taxon-specific compounds. The results this study highlight importance sources potentially role refractory, compounds (carbonates, long-chain lipids, alginates, xylans, sulfated polysaccharides) seagrasses sedimentary storage. This shows do contain refractory thus more valuable previously considered.