Nitrogen uptake and phytoplankton productivity in the changing Arctic Ocean

北极海冰最近的减少是当代地球物理气候变化最明显的例子之一。新资助的北极奖项目(季节性冰区的北极生产力)旨在确定这些海冰变化将如何影响这一气候敏感地区的生物和生物地球化学系统。尽管DON作为浮游植物生长的营养物质已被公认为重要，但关于不同形式的无机和有机N的相对利用以及与浮游植物群落组成的可能联系的信息很少，特别是在北极水域。本研究的目的是评估不同浮游植物大小和功能群对不同形式DIN和DON的相对利用，确定与这些化学(以及物理)驱动因素相关的浮游植物群落组成和丰度的模式，从而评估它们对北极浮游植物生产力和群落组成的影响。假设有机N有可能成为北极浮游植物种群的主要氮源。

The recent decline of Arctic sea ice is one of the most pronounced examples of contemporary physical climate change on Earth. The newly-funded Arctic PRIZE project (Arctic PRoductivity in the seasonal Ice ZonE) aims to determine how these sea ice changes will affect biological and biogeochemical systems in this climatically-sensitive region.Despite the recognised importance of DON as a nutrient for phytoplankton growth, there is little information on the relative utilisation of different forms of inorganic and organic N and possible links to the phytoplankton community composition, especially in Arctic waters. The aim of this study is to evaluate the relative utilisation of different forms of DIN and DON by different phytoplankton size fractions and functional groups, to identify patterns in phytoplankton community composition and abundance associated to these chemical (as well as physical) drivers, and hence to evaluate their influence on Arctic phytoplankton productivity and community composition.Hypothesis Organic N has the potential to act as a major N source for Arctic phytoplankton populations.