Response of temperate microplankton communities to N:Si ratio perturbation
Response of temperate microplankton communities to N:Si ratio perturbation
复制标题
温带微型浮游生物群落对氮硅比扰动的响应
DOI：
10.1093/plankt/fbg109
复制
发表时间：
2003
影响因子：
2.1
通讯作者：
L. Gilpin
中科院分区：
文献类型：
--
作者：
E. Roberts;K. Davidson;L. Gilpin
为了研究氮：硅（N：Si）比例对温带微型浮游生物食物网的影响，在特隆赫姆（挪威）使用两种不同的比例（摩尔比1：1和4：1）进行了中生态实验。除硅藻外，所有微生物群（光养纳米鞭毛虫、自养双鞭毛虫、细菌、异养纳米鞭毛虫（HNAN）、异养微鞭毛虫和纤毛虫）的丰度增加在高 N:Si 处理中显着更大。实验进行到一半时，HNAN 的生物量超过了高 N:Si 处理中的细菌，表明自上而下的放牧控制很强。在两种营养状况下，异养微鞭毛虫生物体积均超过纤毛虫生物体积。然而，异养浮游生物未能对硅藻生物量的增加做出快速反应。在实验的大部分时间里，异养：自养生物体积比保持在<0.1，这表明，在营养物浓度和比例相似的情况下，在小食草动物群落能够做出反应之前，大部分自养产量将通过硅藻聚集和下沉而从地表水中损失掉。讨论了治疗之间硅藻生理学的测量差异，涉及营养质量和对浮游食草动物的影响。
In order to study the effect of the nitrogen:silicon (N:Si) ratio on temperate microplankton food webs, mesocosm experiments were conducted in Trondheim (Norway) using two different ratios (molar ratios of 1:1 and 4:1). With the exception of diatoms, the increase in abundance of all microbial groups [phototrophic nanoflagellates, autotrophic dinflagellates, bacteria, heterotrophic nanoflagellates (HNAN), heterotrophic microflagellates and ciliates] was significantly greater in the high N:Si treatment. Midway through the experiment, HNAN biovolume exceeded that of bacteria in the high N:Si treatment, indicating strong top-down grazing control. Heterotrophic microflagellate biovolume exceeded ciliate biovolume under both nutrient regimes. However, heterotrophic plankton failed to respond rapidly to increased diatom biomass. The heterotrophic:autotrophic biovolume ratio remained <0.1 for the majority of the experiment, suggesting that, given similar nutrient concentrations and ratios, much of the autotrophic production would be lost from surface waters through diatom aggregation and sinking before the micrograzer community was able to respond. Measured differences in diatom physiology between treatments are discussed with respect to nutritional quality and consequences for planktonic grazers.