Carbon and nutrient storage are important ecosystem services of submerged aquatic vegetation (SAV) and may be enhanced by SAV restoration. This study demonstrates an approach to quantifying the nutrient and carbon storage potential of SAV restoration, focusing on the SAV Vallisneria americana in the oligohaline reaches of Florida's Caloosahatchee River Estuary (CRE). The variables of habitat area, plant size, plant density, and tissue nutrient stoichiometry are considered, and estimates are made both for storage in living tissue and for deposition in sediments. System-specific parameter values are obtained from a combination of abundance surveys, historical accounts of abundance and distribution, and field and mesocosm studies of tissue stoichiometry responses to nutrient addition. These are integrated with literature values for sediment deposition rates of C, N, and P in other SAV systems to estimate carbon and nutrient storage for current conditions and various restoration scenarios. Calculations indicate that under a restoration scenario assuming a return to the abundance documented in 1998–1999, V. americana tissues could act as a substantial sink for macro-elements in the CRE, representing 28.4 mt-C, 2.6 mt-N, and 0.16 mt-P, and depositing 897 mt-C y⁻¹, 68.5 mt-N y⁻¹, and 3.87 mt-P y⁻¹ in meadow sediments. However, at current low shoot densities and small shoot sizes, these benefits are two to three orders of magnitude less. In addition to the large difference between the restoration and current-conditions scenarios, propagation of uncertainty around parameter estimates within each scenario leads to wide ranges of uncertainty around model outputs. More system-specific empirical studies would help constrain parameter estimates and improve the model. Overall, these findings emphasize the sensitivity of C, N, and P storage and deposition rates to SAV habitat conditions, and the importance of reversing declines in SAV density through restoration, and other conservation measures.

碳和养分储存是沉水植物 (SAV) 的重要生态系统服务，可以通过 SAV 恢复来增强。本研究展示了一种量化 SAV 恢复的养分和碳储存潜力的方法，重点关注佛罗里达州卡卢萨哈奇河口 (CRE) 寡盐河段的SAV美洲苦草。考虑了栖息地面积、植物大小、植物密度和组织养分化学计量等变量，并对活体组织中的储存和沉积物中的沉积进行了估计。系统特定的参数值是通过丰度调查、丰度和分布的历史记录以及组织化学计量对养分添加的响应的现场和介观研究相结合获得的。这些与其他 SAV 系统中 C、N 和 P 沉积物沉积速率的文献值相结合，以估计当前条件和各种恢复情景下的碳和养分储存量。计算表明，在假设恢复到 1998-1999 年记录丰度的恢复情景下，美洲美洲葡萄组织可以作为 CRE 中大量元素的重要汇，代表 28.4 mt-C、2.6 mt-N 和 0.16 mt-P，并在草甸沉积物中沉积了897 mt-C y ^-1、68.5 mt-N y ^-1和3.87 mt-P y ^{-1 。}然而，在目前芽密度低和芽尺寸小的情况下，这些好处要少两到三个数量级。除了恢复场景和当前条件场景之间的巨大差异之外，每个场景内参数估计的不确定性传播也会导致模型输出的广泛不确定性。更多针对特定系统的实证研究将有助于限制参数估计并改进模型。总体而言，这些发现强调了碳、氮和磷储存和沉积率对 SAV 栖息地条件的敏感性，以及通过恢复和其他保护措施扭转 SAV 密度下降的重要性。