FRES 3041 - UMR 6134, Coastal Ecosystems Team, University of Corsica, 20250, Corte, France.
FRES 3041 - UMR 6134, Coastal Ecosystems Team, University of Corsica, 20250, Corte, France.
Mar Environ Res. 2021 Mar;165:105236. doi: 10.1016/j.marenvres.2020.105236. Epub 2020 Dec 15.
Coastal marine vegetation has been recently highlighted for its highly efficient carbon storage capacity. Among the sixty-four species of seagrass, Posidonia oceanica, a Mediterranean endemic species, appears to be the most effective in carbon fixation and storage. Based on new data from the study of one of the largest P. oceanica meadows in the Mediterranean Sea (100 km of coastline, 20 425 ha), and a synthesis of available data from the whole of the Mediterranean basin, the aim of this work is to evaluate the amount of carbon fixed each year by P. oceanica and sequestered in the matte, in relation with the mitigation of the impact of climate change (carbon sink). The mean total carbon fixation (blades, sheaths and rhizomes) per year varies between 33.5 and 426.6 g C.m and the mean carbon sequestration (long-term sink in the matte), corresponding to the sheath and rhizome tissues, varies between 7.7 and 84.4 g C.m, with a clear decreasing trend according to depth because of the meadow density decrease. The synthesis of a hundred measurements made throughout the Mediterranean Sea and at depths between 0.5 and 32.0 m provides a basis for estimating the average annual carbon fixation and sequestration rate throughout the Mediterranean basin. The fixation of the blades is estimated at 1 024 t C.ha.yr, that of the sheaths at 220 t C ha.yr and that of the rhizomes at 58 t C ha.yr; i.e. a total fixation rate of 1 302 t C ha.yr and sequestration rate (dead sheaths and rhizomes) of 278 t C ha.yr. This annual carbon fixation represents only 0.61% on average of CO emissions/releases for all Mediterranean countries but in the large Mediterranean islands this fixation is on average 3.1% and can reach almost 14.4% for Corsica. Moreover, the major advantage of the P. oceanica meadow lies in its capacity to store carbon from annual carbon sequestration for centuries to millennia and can be compared to several terrestrial ecosystems considered to be efficient in carbon storage (peatlands).
滨海海洋植被因其高效的碳储存能力而备受关注。在 64 种海草中，地中海特有物种波西多尼亚海草似乎在固碳和储存方面最为有效。基于对地中海最大的波西多尼亚海草草甸之一（100 公里海岸线，20425 公顷）的新研究数据，以及对整个地中海盆地现有数据的综合分析，本研究旨在评估每年由波西多尼亚海草固定的碳量及其在草地中的封存量（碳汇），以减轻气候变化的影响。每年叶片、叶鞘和根茎的总碳固定量（ blades, sheaths and rhizomes）变化范围在 33.5 到 426.6g C.m 之间，而长期封存（叶鞘和根茎组织）的碳量变化范围在 7.7 到 84.4g C.m 之间，由于草地密度的下降，深度越深，趋势越明显。对整个地中海地区 100 个测量值的综合分析以及 0.5 到 32.0m 之间的深度分析为估算整个地中海盆地的年平均碳固定和封存率提供了基础。叶片的固定量估计为 1024t C.ha.yr，叶鞘的固定量为 220t C ha.yr，根茎的固定量为 58t C ha.yr；即总固定率为 1302t C ha.yr，封存率（死亡的叶鞘和根茎）为 278t C ha.yr。与所有地中海国家的 CO 排放量/释放量相比，这种年碳固定量平均仅占 0.61%，但在大型地中海岛屿上，这种固定量平均占 3.1%，科西嘉岛甚至可达近 14.4%。此外，波西多尼亚海草草甸的主要优势在于其能够将每年的碳封存储存数百年甚至数千年，这可与被认为在碳储存方面有效的几个陆地生态系统相媲美（泥炭地）。
