The Ecology of the Past

Understanding the “ecology of the past” is essential if we are going to successfully manage and conserve the Earths ecosystems in the face of current and future climatic and environmental change. In studying the ecology of the past we seek to parameterise the how living organisms have interacted with each other and their physical surroundings in the past. Only with these data can we gain empirically based insights into how Earth systems work on timescales that are relevant to the life cycles of trees (100s of years) or the assembly of forest ecosystems (1000s of years). Empirical data on past ecological change can be extracted from sedimentary deposits that have accumulated undisturbed in locations such as lakes. Once sediments have been extracted they can be analysed for different types of evidence, such as pollen to provide information on past vegetation, or charcoal to provide information on past fires. Through analysis of ancient charcoal recovered from sites across the Amazon Basin we have been able to show that during the last 10,000 years fire has been present across this biodiverse region; however, we also show that the amount of fire in eastern Amazonia is far greater than that in western Amazonia. This suggests that the forests of eastern Amazonia might be relatively more resilient to elevated fires today.