September 14, 2012

Study shows wildfires' positive and negative economic impacts

Despite the disruptions they cause, large wildfires are a mixed economic bag for nearby communities, according to findings from a research project by the University of Oregon's Ecosystem Workforce Program and its collaborators.
Wildfires disrupt the lives of workers, employers and families, and lead to longer-term instability in local labor markets, the project funded by Joint Fire Science Program found. But on the flip side of the coin, countywide employment and wages increase in some sectors during the wildfires, often mitigating the short-term employment disruptions wildfires cause.

September 9, 2012

Airborne Technology Helps Manage Elephants

For years, scientists have debated how big a role elephants play in toppling trees in South African savannas. Tree loss is a natural process, but it is increasing in some regions, with cascading effects on the habitat for many other species. Using high resolution 3-D mapping, Carnegie scientists have for the first time quantitatively determined tree losses across savannas of Kruger National Park. They found that elephants are the primary agents—their browsing habits knock trees over at a rate averaging 6 times higher than in areas inaccessible to them. The research also found that elephants prefer toppling trees in the 16-to-30 foot (5-8 m) range, with annual losses of up to 20% in these height classes. The findings, published in Ecology Letters, bolster our understanding of elephant conservation needs and their impacts, and the results could help to improve savanna management practices.

How iron reacts in the environment?

Using ultrafast X-rays, scientists for the first time have watched how quickly electrons hop their way through rust nanoparticles.This gives key insight to how iron oxide, one of the most abundant minerals in soil, behaves and alters the condition of soil and water around it. This also demonstrates the potential of time-resolved X-ray and optical methods to study chemical reactions at the subnanoscale in other semiconductors.

Scientists have long known that certain minerals, redox active ions and biological proteins can exchange electrons to initiate chemical changes in the mineral. But the process of how electrons hop from atom to atom inside a nanoparticle to facilitate change has been too fast to see until now. The same process controls charge collection in solar energy devices involving metal oxides, and thus this work may have relevance to new energy technologies.