A new U.N. study finds that more than 80 percent of the world's oldest virgin forests are concentrated in just 15 countries. The list includes Australia, Bolivia, Brazil, Canada, China, Colombia, the Democratic Republic of Congo, India, Indonesia, Mexico, Papua New Guinea, Peru, Russia, the United States, and Venezuela.

U.N. Environment Program Director Klaus Toepfer says it will take "a miraculous transformation" in the attitude of people and governments to save the remaining dense forests.

Mr. Toepfer says pressure is especially severe on tropical forests, which are disappearing at a rate of about 15 million hectares per year. He says the trend is likely to continue. "I believe that there is a lot of probability that, especially in developing countries, we will have also in the future an ongoing decrease of the native forests," he said.

Mr. Toepfer says one way to reverse the trend is with debt for nature schemes that let developing countries pay off international debts in exchange for increasing their protection of forestlands.

The U.N. data is based on American weather satellite photos taken in the 1990's. A companion study is due out next year based on more recent European satellite data. U.N. experts say they will then be able to compare deforestation rates and determine which countries need help most urgently.