Friday, October 30, 2009

Tree mummies

How could I resist a headline like this: Tree "Mummies" Found! On Wednesday, National Geographic revealed that Norwegian researchers have discovered 40 dead Scotch pines that date back to Viking times. This wouldn't be so surprising if they had petrified, but they simply didn't rot and the scientists don't know why. The trees lived for several hundred years, died natural deaths, and laid on the forest floor near a fjord on the rainy west coast of Norway.
In yesterday's science news, plant biologists at the University of Vermont found that trees actually facilitate wildfires to prevent other trees from displacing them. "We used a mathematical model to show that positive feedback loops between fire frequency and savannah trees, alone or together with grasses, can stabilize ecological communities in a savannah state, blocking conversion of savannahs to forest." The longleaf pine and the Florida slash pine both engineer their own future by dropping needles that become fodder for fires that limit the spread of more trees.
Speaking of engineering, scientists at the University of Washington have found that trees will power a small circuit. They plugged electrodes into a tree that generated the 10 nanowatts the device consumed. "Normal electronics are not going to run on the types of voltages and currents that we get out of a tree...[But] as new generations of technology come on-line, I think it's warranted to look back at what's doable or what's not doable in terms of a power source," says one of the researchers, although he admits that they haven't exactly established where these voltages come from.
Glad to know that trees still hold some secrets...

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