铁引发的亚北极浮游植物繁荣的衰落和命运
Philip W Boyd1, Cliff S Law, C S Wong
1NIWA Centre for Chemical and Physical Oceanography, Department of Chemistry, University of Otago, PO Box 56, Dunedin, 9003, New Zealand. p.boyd@niwa.co.nz
Nature
|April 3, 2004
概括
铁受精刺激了植物浮游生物的繁荣,但大量的固定碳被细菌和牧草动物丢失,而不是深海出口. 酸耗尽和低效的碳转移极限封存潜力.
科学领域:
- 海洋学 海洋学 海洋学
- 生物地质化学生物地质化学
- 海洋生态海洋生态学
背景情况:
- 高酸盐,低 (HNLC) 的海洋地区往往受到铁的可用性限制.
- 由铁激发的浮游植物的繁荣,在海洋碳循环中发挥着至关重要的作用.
- 在这些开花之后,从地表水域到海洋内部的碳出口效率尚不清楚.
研究的目的:
- 为了研究来自铁刺激的藻花的微粒有机碳 (POC) 的衰退和命运.
- 量化碳出口效率并确定损失途径.
- 评估对过去的铁肥事件和未来的碳封存策略的影响.
主要方法:
- 监测阿拉斯加湾在铁添加后藻的开花情况.
- 测量混合层颗粒有机碳 (POC) 和颗粒.
- 在50-125米深处部署沉积陷以量化出口流量.
- 评估细菌再矿化和中动物浮游生物放牧影响.
主要成果:
- 由于铁和酸耗尽,花期终止了.
- 混合层的POC在开花结束后迅速下降.
- 越来越多的颗粒性石材出口在显著的POC出口之前.
- 细菌再矿化和放牧占POC赤字的一半以上.
- 只有很小一部分POC被出口到永久热带线以下.
结论:
- 酸耗尽限制了藻花的持续时间和随后的碳出口.
- 铁刺激的碳出口到深海是低效的.
- 这些发现挑战了关于地质铁肥和拟议的海洋碳捕集方法的假设.
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