Aspen Times: As the U.S. Forest Service looks for ways to use vast amounts of beetle-killed wood, an ages-old process called biochar is emerging as an option. Pre-Columbian natives in North and South America already knew that adding charcoal to certain soils would help with fertility and water retention. Now, scientists say it can also help prevent the build-up of greenhouse gases. “I got tuned into a different way of looking at our treatments for biomass,” said Bernie Weingardt, explaining …