September 20, 2013

Why don't trees bleed to death when they get injured?

Researchers from Virginia Tech; George-August University in Gottingen, Germany; and the Jackson Laboratory in Bar Harbor, Maine, have discovered how “check valves” in wood cells control sap flow and protect trees when they are injured.

A powerful new type of microscope, the 4Pi, has allowed scientists to see nanostructures inside of microscopic structures known as bordered pits within wood fiber cells. Previously, wood had to be dried, coated with carbon, and put under a high vacuum to be studied at the nanolevel. But the 4Pi, combined with an optical imaging technique called confocal laser scanning microscopy, makes it possible to see the wood cells in a more natural state, which has led to some interesting discoveries.