利用生物标记对南极洲高纬度地区罗斯岛上的阿德利企鹅群落的种群历史所做的重建表明,企鹅种群在公元1500年和公元1800年之间的“小冰期”时期大增。发表在本期Scientific Reports上的这些发现与来自南极洲其他更靠北的地区的结果有所不同,说明气候变化的不同反应可能会出现在南极洲的低纬度地区和高纬度地区。
企鹅种群动态会受气候和环境因素如海面温度、气温、积雪和食物丰富程度等的影响。以前的研究表明,南极洲海洋地区的企鹅种群数量在气候变得比较温暖时增加,在气候变得比较寒冷时减少。在寒冷时期,海冰的增加会阻止企鹅通过海滩进入其聚居地,而缺少食物也会是一个问题。
Zhou-Qing Xie及同事利用在罗斯岛上的Cape Bird收集到的沉积物中的生物标记来重建过去700年间阿德利企鹅群落中的种群变化。他们发现,该地区在“小冰期”开始时从一个海豹生境变成了一个企鹅生境——当时的夏季气温要比之前的200年低大约2℃,然后企鹅便成了支配性物种。他们的重建结果表明,企鹅种群数量在大约公元1490年和公元1670年之间达到顶峰。作者指出,海冰范围的扩大能提供丰富磷虾,这是企鹅的一个重要食物来源。他们得出结论认为,南极洲不同纬度地区的企鹅种群可能会因为气候变化而发生不同变化。(生物谷 Bioon.com)
生物谷推荐的英文摘要
Nature doi:10.1038/srep02472
Increase in penguin populations during the Little Ice Age in the Ross Sea, Antarctica
Qi-Hou Hu,1, 3 Li-Guang Sun,1, 3 Zhou-Qing Xie,1, 3 Steven D. Emslie2 & Xiao-Dong Liu1
Penguins are an important seabird species in Antarctica and are sensitive to climate and environmental changes. Previous studies indicated that penguin populations increased when the climate became warmer and decreased when it became colder in the maritime Antarctic. Here we determined organic markers in a sediment profile collected at Cape Bird, Ross Island, high Antarctic, and reconstructed the history of Adélie penguin colonies at this location over the past 700 years. The region transformed from a seal to a penguin habitat when the Little Ice Age (LIA; 1500–1800 AD) began. Penguins then became the dominant species. Penguin populations were the highest during ca. 1490 to 1670 AD, a cold period, which is contrary to previous results in other regions much farther north. Different responses to climate change may occur at low latitudes and high latitudes in the Antarctic, even if for same species.