Thatje Sven, Hillenbrand Claus-Dieter, Mackensen Andreas, Larter Rob
National Oceanography Centre, Southampton, School of Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, United Kingdom.
Ecology. 2008 Mar;89(3):682-92. doi: 10.1890/07-0498.1.
Today, Antarctica exhibits some of the harshest environmental conditions for life on Earth. During the last glacial period, Antarctic terrestrial and marine life was challenged by even more extreme environmental conditions. During the present interglacial period, polar life in the Southern Ocean is sustained mainly by large-scale primary production. We argue that during the last glacial period, faunal populations in the Antarctic were limited to very few areas of local marine productivity (polynyas), because complete, multiannual sea-ice and ice shelf coverage shut down most of the Southern Ocean productivity within today's seasonal sea-ice zone. Both marine sediments containing significant numbers of planktonic and benthic foraminifera and fossil bird stomach oil deposits in the adjacent Antarctic hinterland provide indirect evidence for the existence of polynyas during the last glacial period. We advocate that the existence of productive oases in the form of polynyas during glacial periods was essential for the survival of marine and most higher-trophic terrestrial fauna. Reduced to such refuges, much of today's life in the high Antarctic realm might have hung by a thread during the last glacial period, because limited resources available to the food web restricted the abundance and productivity of both Antarctic terrestrial and marine life.
如今，南极洲呈现出地球上一些最为恶劣的生命生存环境。在上一个冰川期，南极的陆地和海洋生物面临着更为极端的环境条件挑战。在当前的间冰期，南大洋的极地生物主要依靠大规模的初级生产来维持生存。我们认为，在上一个冰川期，南极的动物种群仅限于当地海洋生产力较高的极少数区域（冰间湖），因为完整的多年海冰和冰架覆盖使得当今季节性海冰区域内的大部分南大洋生产力停滞。在相邻南极内陆发现的含有大量浮游和底栖有孔虫的海洋沉积物以及化石鸟类胃油沉积物，都为上一个冰川期冰间湖的存在提供了间接证据。我们主张，冰川期以冰间湖形式存在的高产绿洲对于海洋生物以及大多数高营养级陆地动物的生存至关重要。由于食物网可用资源有限，限制了南极陆地和海洋生物的数量及生产力，在上一个冰川期，如今南极高纬度地区的大部分生命可能都命悬一线，只能退缩到这些避难所中。
