We report a 12-yr data set (August 2006–October 2018) of nearly continuous estimates (n = 3275) of gross primary production (GPP), community respiration (CR), and net community production (NCP) in a Posidonia oceanica seagrass meadow, computed from O₂ measurements on a mooring at 10 m bottom depth in the Bay of Revellata (Corsica). Both NCP and CR were correlated to GPP and followed the leaf biomass seasonal cycle. The meadow was net autotrophic (NCP of 23 ± 8 mol O₂ m⁻² yr⁻¹, GPP [83 ± 16 mol O₂ m⁻² yr⁻¹] > −CR [−60 ± 9 mol O₂ m⁻² yr⁻¹]), in agreement with oxygen oversaturation (104% at annual scale, 101% in winter, and 109% in summer). Calcification (CAL) and CaCO₃ dissolution (DIS) rates were evaluated from dissolved inorganic carbon measurements in benthic chamber incubations (August 2006–2009). The meadow was found to be a net sink of CaCO₃ (DIS > CAL) at an annual rate of 7 mol CaCO₃ m⁻² yr⁻¹ that matched estimates of CaCO₃ deposition on the meadow by sedimentation from the water column. CAL from epiphyte coralline algae was correlated to GPP, but CAL : GPP ratio (0.1) was lower than reported for coralline algae in cultures (0.6) due to the additional contribution of Posidonia to GPP. Both NCP and net DIS contributed to an annual CO₂ sink of −30 mol CO₂ m⁻² yr⁻¹ distinctly stronger than the estimated net air-sea CO₂ flux (−1 mol CO₂ m⁻² yr⁻¹). This suggests that CO₂ input by vertical mixing and/or transport by horizontal advection also strongly contribute to the net atmospheric CO₂ exchange.

中文翻译：

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Posidonia Oceanica草甸的网络群落代谢

我们报告了一个 12 年的数据集（2006 年 8 月至 2018 年 10 月）， 对Posidonia Oceanica海草的初级生产总值 (GPP)、群落呼吸 (CR) 和净群落生产 (NCP) 进行了近乎连续的估计 ( n = 3275)草甸，根据Revellata 湾（科西嘉）底部 10 m 处系泊处的O ₂测量值计算得出。NCP 和 CR 都与 GPP 相关，并遵循叶生物量季节性周期。草地是净自养的（NCP 为 23 ± 8 mol O ₂ m ^-2  yr ^-1，GPP [83 ± 16 mol O ₂ m ^-2  yr ^-1 ] > -CR [-60 ± 9 mol O ₂ m ^-2 年^-1])，与氧饱和度一致（年度比例为 104%，冬季为 101%，夏季为 109%）。钙化 (CAL) 和 CaCO ₃溶解 (DIS) 速率通过对底栖室孵化（2006-2009 年 8 月）中溶解无机碳的测量进行评估。发现草甸是 CaCO ₃ (DIS > CAL)的净汇，年速率为 7 mol CaCO ₃ m ^-2  yr ^-1，这与通过水柱沉积对草甸CaCO ₃沉积的估计值相匹配。来自附生珊瑚藻的 CAL 与 GPP 相关，但由于Posidonia的额外贡献，CAL : GPP 比率 (0.1) 低于培养物中珊瑚藻的报告 (0.6)到 GPP。NCP 和净 DIS 都促成了 -30 mol CO ₂ m ^-2  yr ^-1的年度 CO ₂汇，明显强于估计的净海气 CO ₂通量（-1 mol CO ₂ m ^-2  yr ^-1）。这表明通过垂直混合和/或通过水平平流输送的CO ₂输入也对净大气 CO ₂交换有很大贡献。