Hydrodynamic and biogeochemical evolution of a restored intertidal oyster (Crassostrea virginica) reef
Hydrodynamic and biogeochemical evolution of a restored intertidal oyster (Crassostrea virginica) reef
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恢复的潮间带牡蛎（Crassostrea virginica）礁的水动力和生物地球化学演化
DOI：
10.1016/j.scitotenv.2022.154879
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发表时间：
2022
影响因子：
9.8
通讯作者：
Chambers, Lisa
中科院分区：
文献类型：
--
作者：
Cannon, David;Kibler, Kelly;Walters, Linda;Chambers, Lisa
牡蛎礁恢复越来越多地被用作恢复退化水生系统中失去的生态系统服务的工具，但关于这种做法的有效性以及何时/是否恢复的珊瑚礁可能与完整的天然珊瑚礁表现相似的问题仍然存在。在本案例研究中，实地观察突出了恢复的潮间带牡蛎礁相对于附近完整和退化的珊瑚礁的冠层、水动力学和生物地球化学特征的短期（恢复后< 1个月）和长期（30个月; 3个补充周期）转化。在12个月的恢复，活牡蛎密度（326牡蛎/平方米），平均壳长（47毫米），平均冠层高度（76毫米）没有显着不同的参考礁上观察到的。在恢复过程中降低礁顶，重新建立了过礁流和周期性潮汐淹没，改善了通道和礁面之间的水力连通性。这立即恢复了大部分珊瑚礁的水动力功能，并消除了在以前退化的珊瑚礁上观察到的不规则流动模式。结果表明，平均流量（河道至礁石水流衰减：98%/62%;林冠内/林冠上方）和速度标准化湍流（w'2 <$/U 2：10− 1/10− 2; w'2 <$/U 3：10 0/10− 2 m− 1）的特征在恢复1年内的恢复和参考礁之间相似，冠层内混合的时间变化归因于活牡蛎密度的增加。参考礁和恢复礁的营养库（平均总碳、总氮）在1年内的变化幅度相似（C：39 & 33 g/kg，N：1.5 & 1.8g/kg），而DOC和NH 4+的增加与活牡蛎的存在相关。恢复珊瑚礁上发生的大多数变化都与牡蛎招聘和树冠生长有关，通过直接流动相互作用调节水动力学，并通过废物沉积和掩埋控制沉积物营养物质和有机物含量。
Oyster reef restoration is increasingly used as a tool for restoring lost ecosystem services in degraded aquatic systems, but questions remain about the efficacy of the practice and when/if restored reefs may behave similarly to intact natural reefs. In this case study, field observations highlighted short-(< 1 month post-restoration) and longer-term (30 months; 3 recruitment cycles) transformations in canopy, hydrodynamic, and biogeochemical characteristics of a restored intertidal oyster reef relative to nearby intact and degraded reefs. Within 12 months of restoration, live oyster density (326 oysters/m 2), mean shell length (47 mm), and mean canopy height (76 mm) did not differ significantly from those observed on a reference reef. Lowering of the reef crest during restoration reestablished over-reef flow and periodic tidal inundation, improving hydraulic connectivity between the channel and the reef surface. This immediately restored much of the reef's hydrodynamic function and eliminated the irregular flow patterns observed on the previously degraded reef. Results showed that mean flow (channel-to-reef flow attenuation: 98%/62%; within/above canopy) and velocity normalized turbulence (w'2¯/U 2: 10− 1/10− 2; ϵ/U 3: 10 0/10− 2 m− 1) characteristics were similar across the restored and reference reefs within 1 year of restoration, with temporal changes in mixing within the canopy attributed to increases in live oyster density. Nutrient pools (mean total carbon, total nitrogen) on reference and restored reefs had similar magnitudes within 1 year (C: 39 & 33 g/kg, N: 1.5 & 1.8 g/kg), while increases in DOC and NH 4+ were correlated with the presence of live oysters. Most changes that occurred on the restored reef were linked to oyster recruitment and canopy growth, which modulated hydrodynamics through direct flow interactions and controlled sediment nutrient and organic matter content through waste deposition and burial.