PDF(Pubmed)
Abstract：
Respiration of lipids by copepods during diapause (overwintering dormancy) contributes to ocean carbon sequestration via the seasonal lipid pump (SLP). Parameterizing this flux in predictive models requires a mechanistic understanding of how life history adaptation in copepods shapes their timing of exit from diapause. We investigate the optimal phenology of Calanus finmarchicus in the Norwegian Sea using an individual-based model in which diapause exit is represented as a trait characterized by phenotypic mean and variance. Without interannual variability, optimal exit correlated with the onset of the spring phytoplankton bloom and phenotypic variance was of no benefit. In contrast, copepods endured reduced fitness and adopted bet-hedging strategies when exposed to interannual variability in bloom timing and predation: later exit from diapause and phenotypic variance maintained adult numbers in anomalous late-bloom years. Exit nevertheless remained well before the peak of the bloom which is a favorable strategy when low predation early in the year enhances survival of eggs and early developmental stages. Our work highlights the complex interactions between C. finmarchicus and its environment and the need for improved understanding of bet-hedging strategies and the cues of diapause exit to progress the representation of the SLP in global biogeochemical models.
摘要：
co足类在滞育（越冬休眠）期间的脂质呼吸有助于通过季节性脂质泵（SLP）实现海洋碳固存。在预测模型中对这种通量进行参数化需要对co足类动物的生活史适应如何影响其退出滞育的时间进行机械理解。我们使用基于个体的模型研究了挪威海Calanusfinmarchicus的最佳物候，在该模型中，滞育退出表示为以表型均值和方差为特征的性状。没有年际变化，最佳出口与春季浮游植物水华的开始相关，表型变异无益。相比之下,co足类动物在开花时间和捕食的年际变化中经历了适应性下降，并采用了下注策略：后来退出滞育和表型变异在异常的开花后期保持了成年人数。尽管如此，退出仍在开花高峰之前，这是一种有利的策略，因为在年初的低捕食会增强卵的存活率和早期发育阶段。我们的工作强调了C.finmarchicus与其环境之间的复杂相互作用，以及需要更好地理解下注策略和滞育退出的线索，以促进SLP在全球生物地球化学模型中的代表性。
