Collaborative Research: Rates of Long-Term Climate and Vegetation Change in Eastern North America and Europe

1980年以来化石-花粉数据变化率的分析 北美东部的许多地点经历了重大的 在10，000 - 14，000年前的最后一次冰川消退期间发生了变化， 在过去的1000年里。 的主要目标 建议的研究是确定时间，幅度， 气候和植被变化的地理格局 在过去的3000年中，在北美东部， 在过去的14,000年里。 高频花粉数据来自 北美东部的一系列站点将被用于 详细分析了发生在 在过去的一千年里，并整理出气候和后- 哥伦比亚人为原因。 来自40个晚冰期站点的数据 在瑞典南部将被用来比较时间结构 斯堪的纳维亚晚冰期与北美的冰川相比较。 可归因于农业和其他因素的植被变化率 人类活动（相对于气候影响）将是 通过对比瑞典的网站进行评估， 密集的人类影响，来自边缘地区的人， 影响不大。 这项研究将确定 北美东部和欧洲的植被迅速变化， 同步，因此将确定主要快速 大气环流的变化。 结果还将揭示 最近的植被是短暂的程度， 北美的定居植被无疑是一种 现代研究的稳态基线。

Analyses of rates of change in fossil-pollen data from eastern North America reveal that many sites experienced major changes 10,000-14,000 years ago during the last deglaciation and again during the last 1000 years. The major objective of the proposed research is to determine the timing, magnitude, and geographic patterns of the changes in climate and vegetation during the past 3000 years in eastern North America and during the past 14,000 years in Sweden. High-frequency pollen data from an array of sites across eastern North America will be used to analyze in detail the apparently rapid changes occurring during the past millennium and to sort out the climatic and post- Columbian anthropogenic causes. Data from 40 late-glacial sites in southern Sweden will be used to compare the temporal structure of the Scandinavian late-glacial with that of North America. Rates of vegetation change attributable to agriculture and other human activities (as opposed to climatic influences) will be evaluated by contrasting Swedish sites from areas having intensive human impact iwth those from marginal areas receiving little impact. This research will establish the degree to which rapid vegetation changes in eastern North America and Europe are synchronous and will thus identify probable times of major rapid changes in atmospheric circulation. The results will also reveal the degree to which recent vegetation is transitory and to which presettlement vegetation in North America justifiably serves as a steady-state baseline for modern studies.