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

尽管在过去的几年里，我们对微生物食物网的复杂性的了解有了很大的提高，但到目前为止，人们对营养动态对氮再生的影响还知之甚少。到目前为止，格雷夫特博士的工作让我们相信，天然食物网中的总氮再生比组成种群的氮再生要大，而且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衡量氮的再生有重要的影响，并暗示常用的分级技术可能会导致对总再生的低估。如果这种偏向的程度很大，即使只是在确定的条件下，那么我们对“新的”和“再生的”氮之间平衡的观点也可能是有偏见的。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在一系列条件下这些相互作用的影响的大小，以及促成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的再生中所扮演的复杂角色，以及它们与浮游生物食物网的其他成分的相互作用如何调节氮素的流动。

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.