Environmental niche overlap in sibling planktonic species calanus finmarchicus and c. glacialis in Arctic fjords

Knowledge of the environmental preferences of the key planktonic species, such as Calanus copepods in the Arctic, is crucial to understand ecosystem function and its future under climate change. Here we assessed the environmental conditions influencing the development stages of Atlantic C. finmarchicus and Arctic C. glacialis, and quantified the extent to which their niches overlap by incorporating multiple environmental data. We based our analysis on a three-year seasonal collection of zooplankton by sediment traps, located on moorings in two contrasting Svalbard fjords: the Arctic Rijpfjorden, and the Atlantic-influenced Kongsfjorden. Despite large differences in water temperature between the fjords, local realized niches of the sibling Calanus species overlapped almost perfectly. The exception was the earliest copepodites of C. glacialis in Rijpfjorden, which probably utilized the local ice algal bloom in spring. However, during periods with no sea ice, like in Kongsfjorden, the sibl..., ,

了解关键浮游物种（如北极哲水蚤属（Calanus）桡足类）的环境偏好，对于理解生态系统功能及其在气候变化背景下的未来演化至关重要。本研究评估了影响大西洋哲水蚤（Calanus finmarchicus）与北极哲水蚤（Calanus glacialis）发育阶段的环境条件，并通过整合多组环境数据，量化了二者生态位的重叠程度。本研究的分析基于三年的季节性浮游动物沉积物陷阱采样数据，采样点设置在斯瓦尔巴群岛两处特征迥异的峡湾的锚定装置上：北极型的里普峡湾（Rijpfjorden）与受大西洋影响的孔斯峡湾（Kongsfjorden）。尽管两处峡湾的水温存在显著差异，但这两个近缘哲水蚤物种的局地现实生态位几乎完全重合。唯一的例外是里普峡湾内北极哲水蚤的早期桡足幼体阶段，该类群可能在春季利用了当地的冰藻水华。然而在无海冰的时期，例如孔斯峡湾，这对近缘哲水蚤物种...