Late Quaternary Climate and Vegetation History of the Alaskan North Slope: Calibration of Modern Data

确定北极生态系统对全球变暖的可能反应需要了解过去和现在的苔原群落。尽管现代北美冻土带群落的分布和组成有较好的文献记载，但它们的晚第四纪发展史仍然鲜为人知。该奖项支持对阿拉斯加北部近18000年来的古植被和古气候的研究，以提高我们对低北极地区陆地-气候系统相互作用的认识。作为PALE计划的一部分，这项研究将分析位于阿拉斯加北坡4种冻土带类型的一系列地点的湖泊沉积物。这项工作将集中于校准现代花粉、苔藓孢子和木质素化合物与周围植被和气候参数，以评估它们准确重建过去环境的能力，并将这些校准应用于现代采样期间选择的一组化石记录。拟议的研究通过描述一个鲜为人知的低北极地区的晚第四纪历史，通过校准古环境指标，以及通过提高湖泊记录的分辨率来定义冻土带环境的变化，来实现PALE的目标。

Determining possible responses of Arctic ecosystems to global warming requires an understanding of both the past and present tundra communities. Although the distribution and composition of modern North American tundra communities are relatively well documented, the late-Quaternary history of their development remains poorly known. This award supports an examination of the paleovegetation and paleoclimate of far northern Alaska over the last 18,000 years as a means of improving our knowledge of terrestrial-climate system interactions in Low Arctic settings. This research, as part of the PALE initiative, will analyze lake sediments from a suite of sites located in 4 tundra types of the Alaska North Slope. This work will concentrate on calibrating modern pollen, moss spores, and lignin compounds with surrounding vegetation and climatic parameters to assess their ability to accurately reconstruct past environments and will apply these calibrations to a set of fossil records chosen during the modern sampling. The proposed research addresses the goals of PALE by describing the late-Quaternary history of a poorly know Low Arctic region, by calibrating paleoenvironmental indicators, and by increasing the resolution of lake records for defining variations within tundra environments.