Jungle Fever

Vines are the hallmark of any self-respecting jungle -- picture Tarzan swinging in from offstage -- but the situation is getting a bit out of control in the Amazon rainforest, where vines are growing so quickly they are choking trees and possibly interfering with the ability of forests to soak up greenhouse gases, according to a study published in today's issue of Nature. An international team of scientists found that the dominance of woody vines over trees increased by between 1.7 and 4.6 percent per year in the 1980s and 1990s. The rapid spread of vines, which is the first observed change in plant composition in virgin jungle, might itself stem from the accumulation of greenhouse gases in the Amazon basin. The jungle has been hailed as an efficient absorber of carbon dioxide, the leading greenhouse gas, but vines soak up the gas far more quickly than trees, speeding their growth and throwing the jungle eco-system off balance.