The annual cycle of protozooplankton in the Kiel Bight
The annual cycle of protozooplankton in the Kiel Bight
复制标题
基尔湾原生浮游动物的年度循环
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
V. Smetácek
中科院分区：
文献类型：
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作者：
V. Smetácek
1973年1月至1974年4月，对基尔湾20 m水柱内的原生浮游动物（异养鞭毛类和纤毛虫）组成和生物量进行了44次研究。两组的生物量在春季和秋季都达到了相当的最大值（20米水柱0.3 ~ 0.7 g C m-2），生物量水平在夏季低得多，在冬季最低。春季浮游动物与浮游植物的最大值一致，在一年中的其他时间，浮游动物的储量似乎不受食物限制，因为浮游植物的储量一直很大；观察到许多原生动物摄入了浮游生物细胞，这表明它们的潜在食物供应并不局限于纳米浮游生物。非矽酸盐生物的生物量占主导地位的纤毛虫和tintinids是不重要的。在20 μm纱布浓度的浮游生物样品中，Tintinnids占主导地位，这表明大多数非矽酸盐纤毛虫，无论大小，都没有被保留。当浮游植物的生物量较大（约0.3 g C - m-2）而后浮游动物的生物量较小时，如春季和秋季，原浮游动物是主要的食草动物，其生物量水平与夏季后浮游动物的生物量水平相当（约0.5 g C - m-2）。在浮游生物生长季节，原浮游动物与后浮游动物呈极显著负相关。因此，后者的捕食是调节原生浮游动物种群规模的一个重要因素，尽管其他因素似乎也在起作用。在春秋两季，原浮游动物以放牧群落为主，沉积物对中上层生态系统的损失率最高；在夏季，后浮游动物以草食动物为主，沉积物对中上层生态系统的损失率较低。显然，原生浮游动物的放牧对远洋系统的影响与后浮游动物的放牧有很大的不同。
Protozooplankton (heterotrophic dinoflagellates and ciliates) composition and biomass was studied in a 20-m water column in the Kiel Bight on 44 occasions between January 1973 and April 1974. Both groups attained comparable biomass maxima during spring and autumn (0.3 to 0.7 g C m-2 in the 20-m water column) and biomass levels were much lower in summer and lowest in winter. The spring protozooplankton maximum coincided with that of phytoplankton and during the rest of the year, protozooplankton stocks did not appear to be food limited as phytoplankton stocks were large throughout; many protozoans with ingested microplankton cells were observed, indicating that their potential food supply is not restricted to nanoplankton. Non-loricate organisms dominated biomass of the ciliates and tintinnids were of little importance. Tintinnids predominated in plankton samples concentrated by 20 μm gauze indicating that most non-loricate ciliates, irrespective of size, were not retained. When phytoplankton sotcks were large (>3 g C m-2) but those of metazooplankton small, as in spring and autumn, protozooplankton were the major herbivores with biomass levels comparable to those attained in summer by metazooplankton (≈ 0.5 g C m-2). A highly significant negative correlation was found between protozooplankton and metazooplankton during the plankton growth season. Predation by the latter is thus an important factor regulating size of the protozooplankton population, although other factors also appear to be in operation. Loss rates of the pelagic system through sedimentation are highest in spring and autumn when protozooplankton dominate the grazing community and loss rates are much lower in summer when metazooplankton are the dominant herbivores. Apparently, the impact of protozooplankton grazing on the pelagic system is quite different to that of the metazooplankton.