Submarine groundwater discharge alters coral reef ecosystem metabolism
Submarine groundwater discharge alters coral reef ecosystem metabolism
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DOI：
10.1098/rspb.2020.2743
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发表时间：
2020-12-23
影响因子：
4.7
通讯作者：
Lubarsky, Katie
中科院分区：
文献类型：
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作者：
Silbiger, Nyssa J.;Donahue, Megan J.;Lubarsky, Katie
海底地下水排放（SGD）影响着全球近岸珊瑚礁生态系统。SGD的海洋地球化学是不同的，通常具有更高的营养物质，较低的pH值，较低的温度和较低的盐度比接收沃茨。SGD也可以是人为营养物和其他污染物的管道。使用贝叶斯结构方程模型，我们调查的途径和反馈，SGD影响珊瑚礁生态系统代谢在两个夏威夷网站不同的含水层化学。SGD造成的热环境和地球化学环境改变了净生态系统生产力（NEP）和净生态系统钙化（NEC）。NEP与SGD增强的营养盐呈非线性关系：高通量的中等富集SGD（Wailouth低潮）和低通量的高富集SGD（Kupikipiki'o高潮）增加NEP，但高通量的高富集SGD（Kupikipiki'o低潮）降低NEP，表明向微生物呼吸转变。pH值随NEP波动，驱动钙化菌净生长（NEC）的变化。SGD增强生物反馈：土地利用和气候变化引起的SGD变化将对珊瑚礁群落的钙化产生影响，从而对海岸线保护产生影响。
Submarine groundwater discharge (SGD) influences near-shore coral reef ecosystems worldwide. SGD biogeochemistry is distinct, typically with higher nutrients, lower pH, cooler temperature and lower salinity than receiving waters. SGD can also be a conduit for anthropogenic nutrients and other pollutants. Using Bayesian structural equation modelling, we investigate pathways and feedbacks by which SGD influences coral reef ecosystem metabolism at two Hawai'i sites with distinct aquifer chemistry. The thermal and biogeochemical environment created by SGD changed net ecosystem production (NEP) and net ecosystem calcification (NEC). NEP showed a nonlinear relationship with SGD-enhanced nutrients: high fluxes of moderately enriched SGD (Wailupe low tide) and low fluxes of highly enriched SGD (Kupikipiki'o high tide) increased NEP, but high fluxes of highly enriched SGD (Kupikipiki'o low tide) decreased NEP, indicating a shift toward microbial respiration. pH fluctuated with NEP, driving changes in the net growth of calcifiers (NEC). SGD enhances biological feedbacks: changes in SGD from land use and climate change will have consequences for calcification of coral reef communities, and thereby shoreline protection.