CRB: Tropical Fire Histories from Charcoal Stratigraphy

点击翻译按钮获取中文摘要

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.