We evaluated two rake-enclosure sampling methods for estimating biomass of submersed aquatic vegetation (SAV) within managed tidal impoundments (MTIs) in the Ashepoo-Combahee-Edisto Rivers Basin, South Carolina. We collected SAV using a modified rake within 0.086 m² cylindrical sampler (CS), a non-modified rake within 0.2-m² quadrat (QS), and after raking, hand-collected remaining SAV within each enclosure (i.e., rake + hand = total SAV biomass). We used linear mixed models to evaluate rake sampling methods to estimate total (QS and CS) and species-specific SAV biomass (QS). The marginal coefficient of determination (R²) for both rake sampling methods was 0.95 for estimating total SAV biomass and model fitted values met our a priori acceptable level of precision (CV ≤ 15–20%). Furthermore, the QS-rake method explained 95% of the variation in total widgeongrass biomass (Ruppia maritima), 97% of dwarf spikerush biomass (Eleocharis parvula), and 97% of muskgrass (Chara spp.) biomass but model fitted values only met a priori precision for widgeongrass biomass. We conclude that our rake-SAV sampling estimates total SAV and widgeongrass biomass with little unexplained variation. Furthermore, abiotic variables had no significant effect when estimating SAV biomass. We suggest managers and researchers use our rake methods to estimate biomass of SAV in wetlands with similar species compositions, and resulting estimates may be used to estimate foraging carrying capacity for habitat conservation planning and management.

我们评估了两种耙围采样方法，用于估算南卡罗来纳州阿什波-康巴赫-埃迪斯托河流域受控潮汐蓄水池（MTI）内的水下水生植物（SAV）的生物量。我们使用0.086 m ²圆柱形采样器（CS）内的改良耙子，0.2-m ² Quadrat（QS）内的非改良耙子收集了SAV，耙过后，手工收集了每个围栏内剩余的SAV（即耙子+手） = SAV总生物量）。我们使用线性混合模型来评估耙采样方法，以估计总量（QS和CS）和特定物种SAV生物量（QS）。边际确定系数（R ²），这两种耙采样方法的SAV总生物量估计值为0.95，模型拟合值满足我们的先验可接受精度（CV≤15–20％）。此外，QS-rake方法解释了维吉翁草总生物量（Ruppia maritima）的95％，矮棘花生物量（Eleocharis parvula）的97％和麝香草（Chara）的97％spp。）生物量，但模型拟合值仅满足Widgeongrass生物量的先验精度。我们得出的结论是，我们的耙式SAV采样估计了SAV和Widgeongrass的总生物量，几乎没有无法解释的变化。此外，估计SAV生物量时，非生物变量没有显着影响。我们建议管理人员和研究人员使用耙方法估算具有相似物种组成的湿地中SAV的生物量，所得估算值可用于估算栖息地保护规划和管理的觅食能力。