Millennial-Scale History of Amazon Forest Dynamics
Lead Supervisor: Francis E. Mayle, University of Reading, Department of Geography & Environmental Science, SAGES
Co-supervisors: Stuart Black, Department of Archaeology, SAGES; Shovonal Roy, Department of Geography & Environmental Science, SAGES
Studies of a network of 1-hectare forest plots across Amazonia have revealed significant ecological changes (e.g. increasing biomass) over recent decades, but whether they reflect atmospheric change (e.g. fertilization from rising CO2 concentrations), or instead secondary succession following pre-Columbian (pre-AD1492) human disturbance, is controversial. Furthermore, the likely impact of increasing drought over the 21st century, predicted by climate models, is also uncertain. A palaeoecological approach can potentially reveal the impact of mid-Holocene drought (a potential analogue for future drought) as well as Pre-Columbian land use. However, a major disadvantage with lake-based pollen analysis (the traditional palaeovegetation proxy) is that suitably old lakes are rare in Amazonia, and the spatial resolution of pollen records is generally far too coarse to enable meaningful comparison with ecological data from 1 ha plots. The aim of this project is to circumvent this problem by using a novel suite of palaeoecological proxies from soil profiles to reconstruct the millennial-scale vegetation histories of individual 1 ha plots of different types of forest across ecotonal southern Amazonia.