International Plant Protection Convention grapples with challenges of globalized trade

Oil spills garner much public attention and anguish, but "biological spills" represent a greater long-term threat and do not have the same high public profile.It was an exotic fungus that wiped out billions of American chestnut trees in the early 20th century, dramatically altering the landscape and ecosystem, while today the emerald ash borer - another pest that hitch-hiked along global trade routes to new habitats - threatens to do the same with a valuable tree long used by humans to make tool handles, guitars and office furniture.