红树林生态系统通过沉积物中的碳储存代表了低成本的气候调节系统。然而,考虑到浅层沿海生态系统的复杂变化,从对碳储存的几组环境影响中可以清楚地看出,保存这项服务所需的信息存在缺陷。这里,我们调查了水文因素的时空变异性(水温,pH值,盐度,溶解氧(DO),流速,浊度)和沉积物特征(沉降速率和沉积物粒度)通过检查哪个关键变量控制红树林沉积物有机质(OM),从而影响红树林的复杂碳动力学。我们使用现场监测来评估水文动力学,沉降速率,沉积物有机物含量,和粒度。采用实验室烧失量和粒度方法来量化被困和底部沉积物中的OM以及沉积物粒度,分别。根据调查结果,水pH值,盐度,DO是沉积物中OM的关键调节剂。尽管有传统的期望,研究观察到DO对OM的积极影响,强调水生植物光合作用和淡水流入的可能作用。沉积率,通常认为对OM积累至关重要,没有明显的关系,强调沉积物含量对数量的重要性。值得注意的发现包括沉积物粒度在红树林沉积物中OM存储中的作用。尽管63μm直径的晶粒尺寸等级在研究地点的平均重量最高,陷阱和底部OM与500和2000μm晶粒尺寸类别之间存在显著正相关,强调在碳动力学评估中需要考虑沉积物特征。总的来说,这项研究为红树林生态系统复杂的环境动态提供了宝贵的见解,这些动态对于理解和管理这些重要的沿海栖息地至关重要。
Mangrove ecosystems represent low-cost climate-regulating systems through carbon storage in their sediments. However, considering the complex shifts in shallow coastal ecosystems, it is clear from just a few sets of environmental impacts on their carbon storage that there is a deficit in the information required for preserving this service. Here, we investigated the spatial and temporal variability of hydrographic factors (water temperature, pH, salinity, dissolved oxygen (DO), flow velocity, turbidity) and sediment characteristics (sedimentation rate and sediment grain size) on the intricate carbon dynamics of mangroves by examining which key variable(s) control mangrove sediment organic matter (OM). We used in-situ monitoring to assess the hydrographic dynamics, sedimentation rate, sediment organic content, and granulometry. Laboratory loss-on-ignition and granulometric methods were employed to quantify OM in trapped and bottom sediments and sediment grain size, respectively. Based on the findings, water pH, salinity, and DO were the key regulators of OM in sediments. Despite conventional expectations, the study observed positive effects of DO on OM, highlighting the possible role of aquatic plant photosynthesis and freshwater inflow. Sedimentation rates, usually considered crucial for OM accumulation, showed no significant relationship, emphasizing the importance of sediment content over quantity. Noteworthy findings include the role of sediment grain size in OM storage within mangrove sediments. Even though the grain size class of 63 μm diameter had the highest mean weight across the studied sites, there were significant positive correlations between Trap and Bottom OM with 500 and 2000 μm grain size classes, emphasizing the need to consider sediment characteristics in carbon dynamics assessments. Overall, this research provides valuable insights into the intricate environmental dynamics of mangrove ecosystems that are crucial to understanding and managing these vital coastal habitats.