From laboratory manipulations to Earth system models: scaling calcification impacts of ocean acidification
From laboratory manipulations to Earth system models: scaling calcification impacts of ocean acidification
复制标题
DOI：
10.5194/bg-6-2611-2009
复制
发表时间：
2009-01-01
期刊：
影响因子：
4.9
通讯作者：
Young, J. R.
中科院分区：
文献类型：
--
作者：
Ridgwell, A.;Schmidt, D. N.;Young, J. R.
所观察到的变化的钙化反应的颗石藻碳酸盐化学的变化描绘了一个高度不连贯的画面，特别是最常见的培养“种”，Emiliania huxleyi。在模拟的世纪末海洋表面化学变化（pCO（2）升高、pH值和碳酸盐饱和度降低）下，钙化变化的幅度和潜在甚至符号之间的差异，对量化未来碳循环影响和反馈提出了挑战，因为它在全球模型所用的参数化中引入了重大的不确定性。在这里，我们编译的结果颗石碳酸盐化学操纵实验和审查海洋碳循环模型如何试图弥合从实验到全球影响的差距。虽然我们可以排除碳酸盐化学如何改变的方法差异引入实验偏差，缺乏一致的钙化反应意味着，基于小的和不同的实验观测子集的模型参数化将导致不同的估计全球碳循环的海洋酸化的影响。我们强调了两个相关的观察结果，可能会有所帮助：（1）球石钙化的程度有很大的不同，物种之间和物种内不同的基因型，（2）钙化反应跨围隔和船上孵化迄今已被发现是相对一致的。通过类比浮游生物生长速率与温度的描述，如“Eppley曲线”，它试图通过渐进的组合变化，而不是任何单一物种的响应封装净群落响应，我们认为，未来海洋酸化的进步可能会推动从更多到更少的钙化颗石藻的优势过渡。组合转移可能是更重要的综合社区钙化反应比物种特异性的反应，突出了整个社区的操作实验模型的重要性，在没有一个完整的生理了解的基础钙化过程。然而，在世纪的时间尺度上，无论采用何种参数化，海洋酸化对大气pCO（2）的影响与其他全球碳循环反馈相比都很小。
The observed variation in the calcification responses of coccolithophores to changes in carbonate chemistry paints a highly incoherent picture, particularly for the most commonly cultured "species", Emiliania huxleyi. The disparity between magnitude and potentially even sign of the calcification change under simulated end-of-century ocean surface chemical changes ( higher pCO(2), lower pH and carbonate saturation), raises challenges to quantifying future carbon cycle impacts and feedbacks because it introduces significant uncertainty in parameterizations used for global models. Here we compile the results of coccolithophore carbonate chemistry manipulation experiments and review how ocean carbon cycle models have attempted to bridge the gap from experiments to global impacts. Although we can rule out methodological differences in how carbonate chemistry is altered as introducing an experimental bias, the absence of a consistent calcification response implies that model parameterizations based on small and differing subsets of experimental observations will lead to varying estimates for the global carbon cycle impacts of ocean acidification. We highlight two pertinent observations that might help: (1) the degree of coccolith calcification varies substantially, both between species and within species across different genotypes, and ( 2) the calcification response across mesocosm and shipboard incubations has so-far been found to be relatively consistent. By analogy to descriptions of plankton growth rate vs. temperature, such as the "Eppley curve", which seek to encapsulate the net community response via progressive assemblage change rather than the response of any single species, we posit that progressive future ocean acidification may drive a transition in dominance from more to less heavily calcified coccolithophores. Assemblage shift may be more important to integrated community calcification response than species-specific response, highlighting the importance of whole community manipulation experiments to models in the absence of a complete physiological understanding of the underlying calcification process. However, on a century time-scale, regardless of the parameterization adopted, the atmospheric pCO(2) impact of ocean acidification is minor compared to other global carbon cycle feedbacks.