CRB: Tropical Fire Histories from Charcoal Stratigraphy

该项目将系统地研究热带环境中的火灾与其相应的地层信号之间的关系，这些信号以湖泊、沼泽和洞穴沉积物中的颗粒碳的形式存在（木炭地层学）。测定沉积物木炭含量的习惯方法将与正在开发的利用自动数字图像分析的新方法进行精度，准确性和速度的比较。沉积木炭参数（浓度、流入量、类型、实践尺寸分布）将在以前的项目中收集的大约200个现代沉积物样本中进行测量，这些样本来自北纬43度至南纬25度的一系列地点，包括沙漠、雨林、热带稀树草原、温带森林、耕地、和山地环境。木炭参数将与现场的生态数据（流域类型和规模、植被、气候和当地/区域火灾发生）进行比较。这些信息将用于解释从马达加斯加收集的层状沉积物岩心得出的火灾历史。肯尼亚/坦桑尼亚和波多黎各。初步的年代测定和其他分析表明，这些岩心有望为这些遗址提供数千年的详细火灾历史。这些史前火灾的时间序列数据将提供有关前现代大气的陆地碳输入、人类对史前环境的影响以及气候、Fore, and vegetation。

This project will systematically examine the relationships between fires in tropical environments and their corresponding stratigraphic signals, in the form of particulate carbon in sediments of lakes, bogs, and caves (charcoal stratigraphy). The customary methods for determining charcoal content of sediments will be compared for precision, accuracy, and speed with a new method being developed utilizing automated digital image analysis. Sedimentary charcoal parameters (concentration, influx, type, practice size distribution) will be measured in about 200 modern sediment samples collected in previous projects from an array of sites ranging from 43 N to 25 S, including deserts, rainforests, tropical savannas, temperate forest, cultivated areas, and montane environments. Charcoal parameters will be compared with ecological data on the sites (basin type and size vegetation, climate, and local/regional fire occurrence). This information will be used to interpret fire histories derived from laminated sediment cores collected form Madagascar. Kenya/Tanzania, and Puerto Rico. Preliminary dating and other analyses indicate that these cores can be expected to yield detailed fire histories for the sites spanning several millennia. This time-series data on prehistoric fires will provide insights concerning terrestrial carbon inputs to the pre- modern atmosphere, human impacts on prehistoric environments and linkages between climate, fore , and vegetation.