Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment
Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment
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DOI：
10.5194/bg-5-1517-2008
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发表时间：
2008-01-01
期刊：
影响因子：
4.9
通讯作者：
Brown, K. R.
中科院分区：
文献类型：
--
作者：
Bellerby, R. G. J.;Schulz, K. G.;Brown, K. R.
在2005年远洋生态系统二氧化碳浓缩(PEECE III)实验期间，研究了海水无机碳和营养物浓度的变化，以响应自然浮游生物组合的故意二氧化碳扰动。利用时间无机二氧化碳系统和养分变化的逆分析方法，确定了在一系列PCO(2)情景(350、700和1050亩大气压)扰动下的一个自然远洋生态系统的净群落化学计量吸收特征。养分吸收对CO2处理不敏感。与养分消耗相比，高CO2处理的碳排放增加，且与初始CO2浓度呈正相关。在开花高峰期，虎斑狼尾草对CO2变化没有明显的钙化响应，所有处理都表现出较低的颗粒无机碳产生量(接近15mU/kg)。由于各处理之间的海气二氧化碳交换不显著，碳吸收的增强是由于增加了有机碳的产生。推测的有机生产量的累积C：N：P化学计量比在盛花期从1：6.3：121增加到1：7.1：144到1：8.25：168。这项研究讨论了海洋酸化如何导致中上层生物的化学计量比发生变化，并对海洋生物地球化学循环产生影响。
Changes to seawater inorganic carbon and nutrient concentrations in response to the deliberate CO2 perturbation of natural plankton assemblages were studied during the 2005 Pelagic Ecosystem CO2 Enrichment (PeECE III) experiment. Inverse analysis of the temporal inorganic carbon dioxide system and nutrient variations was used to determine the net community stoichiometric uptake characteristics of a natural pelagic ecosystem perturbed over a range of pCO(2) scenarios (350, 700 and 1050 mu atm). Nutrient uptake showed no sensitivity to CO2 treatment. There was enhanced carbon production relative to nutrient consumption in the higher CO2 treatments which was positively correlated with the initial CO2 concentration. There was no significant calcification response to changing CO2 in Emiliania huxleyi by the peak of the bloom and all treatments exhibited low particulate inorganic carbon production (similar to 15 mu mol kg(-1)). With insignificant air-sea CO2 exchange across the treatments, the enhanced carbon uptake was due to increase organic carbon production. The inferred cumulative C: N: P stoichiometry of organic production increased with CO2 treatment from 1: 6.3: 121 to 1: 7.1: 144 to 1: 8.25: 168 at the height of the bloom. This study discusses how ocean acidification may incur modification to the stoichiometry of pelagic production and have consequences for ocean biogeochemical cycling.