企鹅的生物传输对东南极湖泊生态环境变化的影响

我们前期工作恢复出了企鹅种群数量变化，但对于在南极大量分布的企鹅对栖息地环境的影响目前还很少关注。申请项目拟从企鹅粪带来的营养成分和重金属元素两个角度深入评估企鹅生物传输的生态环境影响。在东南极优选含鸟粪的典型湖泊沉积剖面作为主要研究载体，重点分析沉积色素和生物标志化合物等指标，开展这些指标的现代沉积过程研究，查明这些替代性指标的确切环境意义，据此识别中晚全新世以来湖泊沉积有机质的来源比例，并利用统计分析和软件技术定量地重建湖泊浮游植物群落结构和种群丰度的变化，在同一时间标尺上对比企鹅数量变化历史记录，同时结合典型重金属元素总量和形态在沉积剖面中的变化特征，从历史角度揭示这种独特的生物传输过程对南极湖泊生态环境变化造成的影响，并探讨其机制。研究成果将有助于我们在全球变化背景下更好地评估脆弱的南极湖泊生态系统对气候变化和生物传输的响应过程，为制定保护南极自然生态环境的对策和措施提供科学资料。

In our previous work, we have reconstructed the fluctuation of historical penguin population and its response to climate change. However, the present studies on the impact of penguins, which are widely distributed across Antarctica, on their habitat environment are still scarce. This proposed project will focus on the input of both nutrient components and heavy metals from penguin droppings in order to access the eco-environmental influence of penguin bio-transportation in East Antarctica. For the study purpose, typical lake sediments influenced by guano will be selected as our main study carriers. Biogeochemical indicators such as pigments and biomarker compounds in the sediments will be analyzed emphatically. Based on the study of modern sedimentary processes, we can identify the clear environmental implications of these indicators, and then decode the input ratio of different organic matter sources into lacustrine sediments, and finally quantitatively reconstruct community structure and population abundance of the phytoplankton growing in lakes since Middle-late Holocene. Based on these results, we can carry out comparative research on the evolutionary record of phytoplankton species in lakes and the historical change of penguin population reconstructed in our previous studies at the same time scale. In addition, the concentration change features of bulk and speciation of typical heavy metals in the sediment profiles will be integrated into our analysis in order to better study the impacts and responding mechanism of penguin bio-transportation on the eco-environmental changes of lakes and ponds in East Antarctica. The study results will help us to objectively assess the response process of the fragile Antarctic lake ecosystem to climate change and bio-transportation in the context of global change, and also may provide reference data which is important to work out measures for the protection of natural eco-environment in Antarctica.