Molecular composition of plant parts and sediment organic matter in a Mediterranean seagrass (Posidonia oceanica) mat

Abstract

Molecular composition of plant parts and sediment organic matter in a Mediterranean seagrass (Posidonia oceanica) mat.Aquatic Botany http://dx.doi.org/10. 1016/j.aquabot.2016.05.009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Graphical abstract Highlights-Analytical pyrolysis applied to Posidonia seagrass organs and marine mat deposit -Posidonia phenolic composition dominated by p-hydroxybenzoic acids -Peat-like mat deposits composed predominantly of root, rhizome and sheath materials -We suggest a link between Posidonia chemistry and C accumulation in mats AbstractPosidonia oceanica forms extensive peat-like deposits (mats) in Mediterranean coastal waters, which have a potential as carbon sinks and archives of environmental change.Nonetheless, the organic chemistry of both P. oceanica plant materials, as well as the environmental and diagenetic effects on the composition of its detritus, is poorly understood.We analyzed plant organs of P. oceanica and the coarse organic matter from a mat core spanning 750 yrs using pyrolysis techniques (PY-GC-MS and THM-GC-MS) to improve our understanding of their molecular properties and their preservation upon mat development. It

Seagrass community-level controls over organic carbon storage are constrained by geophysical attributes within meadows of Zanzibar, Tanzania

“…The western carbonate sediments are composed of reef foraminifera, mollusk, echinoderm, and coral components and are characterized as coarse gravelly sand (Table 1), whereas the eastern and southern sediments are composed primarily of remnants from calcareous green algae (Halimeda spp. ; Shaghude et al, 1999), which form algal mounds, allowing for greater deposition of fine particles and deeper accumulations of carbonate mud (Kangwe et al, 2012;Muzuka et al, 2005). The narrow range of sediment properties found across the three meadows we sampled leaves us only the ability to piece together trends with data from others' work and speculate that differences in OC storage among regions of the island are due to the disparity in sediment characteristic since plant traits were similar.…”

Key biogeochemical factors affecting soil carbon storage in <i>Posidonia</i> meadows

“…Here, we observed larger amounts of seagrass-derived C org in shallow meadows (85 % in average), pointing to an important factor driving their higher C org storage capacities compared to that of deeper meadows, namely the carbon preservation potential. Posidonia tissues contain relatively high amounts of degradation-resistant organic compounds in their tissues (e.g., lignin and cellulose; Harrison, 1989;Klap et al, 2000;Torbatinejad et al, 2007) and high C / N ratios (Duarte, 1990;Pedersen et al, 2011;Kaal et al, 2016). In contrast, seston and algal detritus, which contributed as much as 64-75 % of the C org in the deeper sites, have a higher labile C org content (Laursen et al, 1996) more likely to be remineralized during early diagenesis (Henrichs, 1992), potentially explaining the higher soil C org decay rates in the deep (at 8 m) P. sinuosa meadows.…”

Ecological Function of Phenolic Compounds from Mediterranean Fucoid Algae and Seagrasses: An Overview on the Genus Cystoseira sensu lato and Posidonia oceanica (L.) Delile

“…In P. oceanica leaves, tannins account for ca. 5%-10% [15], whereas 2% of the dry weight of leaves corresponds to free or ester-bound phenols [2,3,126]. The remaining amount of phenols is poorly understood.…”