The biological pump in a high CO2 world
The biological pump in a high CO2 world
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DOI：
10.3354/meps09985
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发表时间：
2012-01-01
影响因子：
2.5
通讯作者：
Carlson, Craig A.
中科院分区：
文献类型：
--
作者：
Passow, Uta;Carlson, Craig A.
有机物形成与呼吸作用的垂直分离可导致海洋内部的净碳固存，使生物泵成为全球碳循环的重要组成部分。了解生物泵对环境变化的响应是预测未来大气二氧化碳浓度的先决条件。生物泵会减弱还是增强？目前，海洋科学界还无法自信地回答这个问题。深度约1000 m处的碳通量（封存通量）决定了>= 100年时间尺度上大气中碳的去除。固碳通量取决于：（1）海洋外来营养盐的输入速率，（2）真光层底部的输出通量，（3）固碳和再平衡对Redfield化学计量的偏离，（4）1000 m以上通量的衰减。生物对温度升高、海洋分层、营养物供应和海洋酸化的反应往往因生物分类和生态系统而异，协同效应的结果难以预测。因此，使用全球平均值和稳态假设（例如，G. Redfield化学计量学、中层营养物清单）用于预测模型往往不够。我们预测螯合通量的能力还受到缺乏对中层食物网功能和通量衰减的了解的影响。然而，区域具体的调查显示出很大的希望，这表明，在不久的将来，生物泵的变化预测将必须是区域和生态系统的具体，与全球范围内整合的最终目标。
The vertical separation of organic matter formation from respiration can lead to net carbon sequestration within the ocean's interior, making the biological pump an important component of the global carbon cycle. Understanding the response of the biological pump to the changing environment is a prerequisite to predicting future atmospheric carbon dioxide concentrations. Will the biological pump weaken or strengthen? Currently the ocean science community is unable to confidently answer this question. Carbon flux at approximately 1000 m depth, the sequestration flux, determines the removal of carbon from the atmosphere on time scales >= 100 yr. The sequestration flux depends upon: (1) input rates of nutrients allochthonous to the ocean, (2) the export flux at the base of the euphotic zone, (3) the deviation of carbon fixation and remineralization from Redfield stoichiometry, and (4) the flux attenuation in the upper 1000 m. The biological response to increasing temperature, ocean stratification, nutrient availability and ocean acidification is frequently taxa- and ecosystem-specific and the results of synergistic effects are challenging to predict. Consequently, the use of global averages and steady state assumptions (e. g. Redfield stoichiometry, mesopelagic nutrient inventory) for predictive models is often insufficient. Our ability to predict sequestration flux additionally suffers from a lack of understanding of mesopelagic food web functioning and flux attenuation. However, regional specific investigations show great promise, suggesting that in the near future predictions of changes to the biological pump will have to be regionally and ecosystem specific, with the ultimate goal of integrating to global scales.