南极无冰区生态与环境变化在粪土层中的记录

Eco-environmental Change Records of Antarctic Ice-free Areas in Sediments Influenced by Marine Animals

极地海鸟、海兽等生物排泄物的堆积层和含粪的沉积层是进行极地生态地质学研究的良好载体。从生物粪土沉积层中恢复出的企鹅、海豹数量变化记录表明,历史时期南极企鹅、海豹种群数量出现过显著的波动。在新冰期时企鹅数量锐减,气候过冷或过暖都不利于它们的生存,南极海豹数量变化也受到气候变化、海冰条件和取食行为的控制。另外,南极海豹毛和生物粪土层中还保存了过去几千年人类文明的历史信息,汞(Hg)含量的波动与人类冶金文明的盛衰存在明显的响应关系。

Under the condition of polar eco-environment, the accumulative profiles of seabird and sea animal excrements and the depositional sequences influenced by animal excrements are good archives to study eco-geology in ice-free regions of Antarctica and Arctic. The historical records of Antarctic penguin and seal population changes, which had been reconstructed from the sediments influenced by animal excrements, showed that historically the penguin and seal population had experienced dramatic fluctuations. The period of sharp decrease in penguin populations corresponded well to Neoglaciation, and it may be not suitable for the survival of Antarctic penguin under the extremely cold or warm climate conditions; the historical change of seal population seemed to be related to climatic variation, sea-ice coverage and its forage behavior. Additionally, the results showed that the Antarctic seal hairs and sediments including seal excrements well preserved the historical information of ancient civilization over the past several thousand years, and the fluctuations of Hg concentration in the seal hairs and the excrement sediments were found to be closely coincided with ancient activities of gold and silver mining.