The November 2007 Special Issue of Frontiers in Ecology and the Environment focuses on paleoecology, which uses fossilized remains and soil and sediment cores to reconstruct past ecosystems.
Some scientists argue that the pre-Columbian Amazon was pristine, with indigenous people living in harmony with nature. Others suggest that the Amazon is a manufactured landscape, altered by and disturbed by human activities even before the arrival of Europeans. In Amazonian exploitation revisited: ecological asymmetry and the policy pendulum, Mark Bush (Florida Institute of Technology) and Brian Silman (Wake Forest University) discuss this debate.
Bush and Silman present paleodata from fossil pollen and charcoal in soil cores that support both perspectives. They argue that in some areas of the Amazon, human impact was extreme, especially on bluffs around rivers. Yet they also found vast stretches of the forest where human influence was minimal. If widespread disturbance was typical in the Amazon forest until just 500 years ago, that suggests the ecosystem is resilient to human activities, including logging. However, as the authors demonstrate, the manufactured landscape argument only holds true for localized patches of forest, and should not be used as a basis for management of the Amazon as a whole.
Heading north, the next paper addresses the use of lakes and ponds for reconstructing environmental changes in the Arctic. John Smol (Queens University, Ontario) and Marianne Douglas (University of Alberta, Edmonton) summarize some of the recent lake sediment studies in From controversy to consensus: making the case for recent climate change in the Arctic using lake sediments. Scientists working in these regions have noted recent changes in the abundance of a group of pythoplankton known as diatoms, as well as changes in other plankton. The researchers found striking and often unprecedented changes in post-1850 sediments, which could be link
|Contact: Annie Drinkard|
Ecological Society of America