The Impact of Macrozooplankton on the Measurement of Inorganic and Organic Nitrogen Cycling in Marine Microbial Food Webs

尽管我们对微生物食物网的复杂性的理解在过去几年中有了极大的提高，但迄今为止，对营养动力学对氮再生的影响的认识还很少。到目前为止，格里伯特博士的工作使我们相信，天然食物网中氮的总再生量大于各组成部分所贡献的氮的再生量，而这种影响是大型浮游动物密度的非线性函数。这一假设对我们如何测量氮的再生具有重要的影响，并意味着常用的粒度分馏技术可能会导致对总再生的低估。如果这种偏差的幅度很大，即使只是在某些条件下，那么我们对“新”氮和“再生”氮之间平衡的看法也可能存在偏差。在这些研究中，Glibert博士和合作者将使用几种新开发的技术来确定这些相互作用在一系列条件下的影响程度以及产生这种影响的主要过程。这些研究的意义在于阐明大型浮游动物在控制氮再生中的复杂作用，以及它们如何与浮游生物食物网的其他组成部分相互作用来调节氮的流动。

Although our understanding of the complexity of the microbial food web has increased tremendously over the past several years, there has been little appreciation to date of the effects of trophic dynamics on the regenration of nitrogen. Dr. Glibert's work to date leads us to believe that total nitrogen regeneration in a natural food web is greater than that contributed by the component popultions, and that this effect is a nonlinear function of macrozooplankton density. This hypothesis has important consequences for how we measure the regeneration of nitrogen, and implies that commonly-used size-fractionation techniques may lead to underestimates of total regeneration. If the magnitude of this bias is large, even if only under certian conditions, then our perspective of the balance between "new" and "regenerated" nitrogen may also be biased. In these studies Dr. Glibert and collaborators will use several newly-developed techniques to determine the magnitude of the effect of these interactions under a range of conditions and the major processes contributing to this effect. The significance of these studies lies in elucidating the complex role of macrozooplankton in controlling the regeneration of nitrogen and how their interactions with other components of the plankton food web regulate the flow of nitrogen.