Collaborative Research on Long Paleoenvironmental Records from Cave Sediments

国际上对全球变化日益增长的兴趣刺激了对自然条件的更长记录的发展，以便更好地将自然控制的变化与人类活动引起或加速的过程进行比较。近年来，学者们越来越多地深入地下，检查洞穴中的沉积物，以确定这些沉积物中的花粉和微化石是否可以提供环境条件的长期记录。该项目将继续对从七个不同非洲国家的十个洞穴中收集的材料进行分析。初步分析估计，其中一些物质的年代比现在早35万年。通过继续估算材料的年龄，并将这些材料与洞穴周围地区的特定植被类型联系起来，项目负责人应该能够更全面、更准确地重建洞穴遗址长期的生态条件。然后，这些重建将为更准确地估计这些地区的气候和其他自然条件提供基础。这项研究意义重大，因为它将提供更多关于非洲不同地区数十万年来古生态条件的信息。这些数据将补充为其他地点收集并使用其他测量方法确定年代的长期记录，从而为审查自更新世以来世界各地自然环境变化的性质和过程提供更好的基础。这项研究还将增加关于这项研究中使用的古生态重建方法的知识，以及使用洞穴沉积物作为自然环境条件信息来源的局限性，这些知识将有助于学者研究历史和当前时间范围内的环境变化。

Growing international interest in global change has stimulated development of longer records of natural conditions in order to better compare naturally controlled change with the processes induced or accelerated by human activity. Scholars increasingly have gone underground in recent years, examining sediments in caves to determine whether pollen and microfossils in those deposits can provide long-term records of environmental conditions. This project will continue analysis of materials gathered in ten caves from seven different African nations. Preliminary analyses have estimated the dates of some of these materials to 350,000 years before the present. By continuing the process of estimating the age of materials and associating those materials with specific types of vegetation in regions surrounding the caves, project leaders should be able to more completely and more accurately reconstruct ecological conditions at the cave sites over long time periods. These reconstructions will then provide a basis for more accurate estimation of climate and other natural conditions in those regions. This research is significant because it will provide considerably more information about paleo-ecological conditions in different parts of Africa over hundreds of thousands of years. These data will complement long records gathered for other locales and dated using other methods of measurement, thereby providing an improved basis for examining the nature and processes of natural environmental change throughout the world since the Pleistocene epoch. This research also will increase knowledge about the paleoecological reconstruction methods used in this study and about the limitations in the use of cave sediments as sources of information about natural environmental conditions, knowledge that will help scholars examining environmental change in both historic and current timeframes.