TROPICAL RAINFORESTS TAKE HEAT STRESS IN STRIDE

While drought is a severe concern for some regions dealing with climate change, tropical rainforests during Earth's earlier bout with global warming may have landed an evolutionary break. The rainforests of northern Colombia and Venezuela persisted despite the heat stress, according to research by theSmithsonian Tropical Research Institute, published in the journal Science. As with any chaotic system in crisis, they survived by diversifying their portfolio.

Carlos Jaramillo and a team of researchers studied the pollen trapped in rocks from about 56.3 million years ago. They found evidence of new species emerging, such as plants in the chocolate and passionflower families. This period, called the Paleocene-Eocene Thermal Maximum, saw carbon dioxide levels doubling in about 10,000 years. The warm climate lasted for about 200,000 years.

Today's Amazon and other tropical rainforests will not have the same luxury of time, as they are now facing a similar expected rise in temperatures of 4.5 degrees Fahrenheit albeit in the coming century. Deforestation and other human impacts also make it difficult to predict the fate of these already biologically diverse ecosystems. The Amazon is currently battling its second drought in a decade.

Still, the research suggests that global warming might not be the death blow for rainforests that some fear. Perhaps sustainable forestry in tropical nations could actually be helped by warmer, wetter conditions.