Seagrass ecosystems have a potential role in climate change mitigation due to their ability to store high amount of carbon, particularly in the sediment. Studying the factors and mechanisms responsible for this storing capacity is essential to understand seagrass carbon sink function. Therefore, in this study, we identified the sources of organic carbon (C_org) in seagrass sediments and the implication to C_org stocks from four islands in the Spermonde Islands that located at different zones. We used the Bayesian stable isotope mixing model to estimate the proportional contribution of different sources to sediment carbon. Seagrass meadows that located in adjacent to high anthropogenic activities (deforestation and aquacultures) with direct exposure to wave actions, such as on the Bauluang Island, accumulated organic carbon that derived from multiple sources, where phytoplankton contributed the highest, while on the other three islands that are relatively protected from wave actions, the highest contribution (~ 75%) was from autochthonous production (seagrass-derived). Sediment C_org stocks vary spatially, ranging from 11.9 to 32.1 Mg C ha⁻¹ (based on the obtained depth of 20–55 cm), or 40.5 to 83.5 Mg C ha⁻¹ if extrapolated to 1 m depth. The variability of sediment properties and C_org stocks in this study is not solely determined by the geographical differences (inshore, nearshore and offshore islands), but also influenced by other local factors such as hydrodynamics that control the distribution of carbon sources, anthropogenic pressures and species composition. These factors should be taken into account when developing coastal management strategies, as efforts are being undertaken to include coastal ecosystems (including seagrass ecosystems) on the National Green House Gasses Reduction Strategy.

中文翻译：

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印度尼西亚Spermonde群岛海草沉积物中有机物的来源及其对碳储量的贡献

由于海草生态系统能够储存大量碳，尤其是沉积物中的碳，因此它们在缓解气候变化方面具有潜在作用。研究造成这种储存能力的因素和机制对于理解海草碳汇功能至关重要。因此，在本研究中，我们确定了有机碳（C来源_组织中海草沉积物），并蕴涵到C_的有机萃来自Spermonde群岛中位于不同区域的四个岛屿的种群。我们使用贝叶斯稳定同位素混合模型来估算不同来源对沉积碳的比例贡献。毗邻高人类活动（森林砍伐和水产养殖）且直接受到波浪作用影响的海草草甸，例如在宝ulu岛，积累了来自多种来源的有机碳，其中浮游植物贡献最大，而在其他三个岛上相对受到波浪作用的保护，最大的贡献（〜75％）来自于土生土产（海草衍生）。沉积物_Corg储量在空间上变化，范围从11.9到32.1 Mg C ha ^-1（基于获得的20-55 cm深度），或者如果推断到1 m深度，则为40.5至83.5 Mg C ha ^-1。在这项研究中，沉积物特性和C _org储量的变化不仅是由地理差异（近海，近岸和近海岛屿）决定的，而且还受到其他局部因素的影响，例如控制碳源分布的水动力，人为压力和物种组成。在制定海岸管理策略时应考虑这些因素，因为正在努力将海岸带生态系统（包括海草生态系统）纳入《国家温室气体减排策略》。