Ammonium regeneration by microzooplankton in the Oslofjord
Ammonium regeneration by microzooplankton in the Oslofjord
复制标题
奥斯陆峡湾微型浮游动物的铵再生
DOI：
10.1007/bf00396961
复制
发表时间：
1982
期刊：
影响因子：
2.4
通讯作者：
S. Kristiansen
中科院分区：
文献类型：
--
作者：
E. Paasche;S. Kristiansen
夏季奥斯陆峡湾坡斜上方溶解的无机氮化合物浓度很低，无机氮池的周转时间不超过几个小时。为了研究夏季浮游植物的持续生长是否依赖于微浮游动物的铵排泄，采用15N同位素稀释法测量了NH4+的再生和同化速率。白天0-2 m深度的再生速率为环境NH4+浓度下计算同化速率的0-28%。8月甲藻华的再生速度快于6月和9月的硅藻-甲藻混合华。NH4+主要由45 ~ 200 μm的桡足类、轮虫、丁丁类和异养鞭毛类幼体产生。
Concentrations of dissolved inorganic nitrogen compounds above the pycnocline in the Oslofjord are very low in the summer, with turnover times of the inorganic N pools of no more than a few hours. To investigate the possibility that continued phytoplankton growth in the summer depends on ammonium excretion by microzooplankton, rates of NH4+regeneration and assimilation were measured by a 15N isotope dilution method. Daytime regeneration rates at 0–2 m depth were 0–28% of the calculated assimilation rates at ambient NH4+concentrations. Regeneration was faster during a dinoflagellate bloom in August than in mixed diatom-dinoflagellate blooms in June and September. Most of the NH4+appeared to be produced by juvenile copepods, rotifers, tintinnids, and heterotrophic dinoflagellates in the size fraction 45–200 μm.