Seasonal development of algal biomass in snow-covered fast ice and the underlying platelet layer in the Weddell Sea, Antarctica
Seasonal development of algal biomass in snow-covered fast ice and the underlying platelet layer in the Weddell Sea, Antarctica
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南极洲威德尔海冰雪覆盖的固定冰和下面的血小板层中藻类生物量的季节性发展
DOI：
10.1017/s0954102099000395
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发表时间：
1999
影响因子：
1.6
通讯作者：
Gerhard Dieckmann
中科院分区：
文献类型：
--
作者：
S. Günther;Gerhard Dieckmann
1995年秋、冬、春三季在威德尔海东部调查了冰雪覆盖的快冰和底层血小板层中营养盐状况的季节变化和藻类群落的发育。在上层海冰，秋季硅藻群落成为封闭在随后的冰增长在冬季，下降，并取代了鞭毛虫占主导地位的社会在春季。在这一层中，硝酸盐在春末被完全耗尽，尽管养分在早春已经部分再生。片状冰的逐渐融化对海冰的生长有显著的贡献，从而影响海冰底部的藻类接种。生物质，存在于血小板层的最上层部分，可以在海冰底部后，这部分凝结成固体冰。掺入后，物种组成从较大的和成链物种的较小的细胞大小的物种。同时，净增长率从血小板层内的0.07天-1降至海冰内的0.03天-1。尽管积雪厚度超过20厘米，但最大生物量产量在血小板层中为210 mg chl a m−2，在海冰中为40 mg chl a m−2，而后者的95%位于固结的血小板冰中。这里观察到的总快冰生物量明显低于罗斯海无雪快冰中观察到的生物量，但由于威德尔海南部的积雪代表了南极大部分快冰区，因此这里提供的数据具有普遍价值。
The seasonal changes of the nutrient regime and the development of algal communities in snow-covered fast ice and the underlying platelet layer was investigated in the eastern Weddell Sea during autumn, winter, and spring 1995. In the upper sea ice, an autumnal diatom community became enclosed during subsequent ice growth in winter, declined, and was replaced by a flagellate dominated community in spring. In this layer, nitrate was completely exhausted at the end of spring, although nutrients had been partly regenerated in early spring. The progressive congelation of platelet ice contributed significantly to sea ice growth thus influencing algal inoculation of the sea ice bottom. Biomass, present in the uppermost section of the platelet layer, could be found in the sea ice bottom after this section congealed to solid ice. After incorporation, species composition changed from larger and chain-forming species to species of smaller cell size. Concurrently, net growth rate slowed down from 0.07 day−1 within the platelet layer to 0.03 day−1 within the sea ice. Despite a thick snow cover of more than 20 cm, maximum biomass yield was 210 mg chl a m−2 in the platelet layer and 40 mg chl a m−2 in the sea ice respectively, while 95% of the latter was located within consolidated platelet ice. Total fast ice biomass observed here is significantly lower than that observed in snow-free fast ice of the Ross Sea, but because snow cover of the southern Weddell Sea is representative of most fast ice areas in the Antarctic, the data presented here are of general value.