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 Miles 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 linked to ecological shifts consistent with global warming. Further changes are predicted to be greatly amplified in the polar regions, putting the ecological integrity of these sensitive ecosystems at risk.
In another paper, “Paleoecology and ‘inter-situ’ restoration on Kauai, Hawaii,” David Burney (National Tropical Botanical Garden, Hawaii) and Lida Pigott Burney (Makauwahi Cave Reserve, Kalaheo) examine human-caused extinctions on the Hawaiian island of Kauai. Paleoecological studies from around the world show the devastating effects of human colonization on islands. Island histories reveal that hunting and landscape changes caused by humans each play a key role, but many of the extinctions seen on islands are probably from introduced predators, herbivores, plants, and diseases. On the island of Kauai, conventional conservation tactics focus on both restoring organisms in the wild as well as using zoos, botanical gardens and genetic banks. However, these tactics aren’t working well. The authors propose that conservationists try inter-situ conservation - the establishment of species by reintroduction to locations outside the current range but within the recent past range of the species. This method could provide a hedge against extinction.
Another paper in the Special Issue, “Paleoecology and ecosystem restoration: case studies from Chesapeake Bay and the Florida Everglades,” by Debra Willard and Thomas Cronin (US Geological Survey), focused on using paleoecology as a restoration tool. John Williams (University of Wisconsin, Madison) and Steve Jackson (University of Wyoming, Laramie) created a simulation of future climates and ecological responses based on the Intergovernmental Panel on Climate Change’s emission scenarios in the year 2100 in their paper, “Novel climates, no-analog communities, and ecological surprises.” Daniel Gavin (University of Oregon, Eugene) and colleagues looked at charcoal records from lake sediments and soil profiles in “Forest fire and climate change in western North America: insights from sediment charcoal records.” Their study focuses on historic forest fire ranges to better understand the vulnerability of all habitats to fire.
Annie Drinkard | EurekAlert!
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The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
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