for National Geographic News
What's a cloud forest without its shroud of cloud? Threatened, says a group of researchers.
The clouds over the Monteverde cloud forests of Costa Rica are shrinkingand sitting higher above the mountain peaksas a result of deforestation in the lowlands, according to a study in the October 19 issue of the journal Science. Robert Lawton, a forest ecologist at the University of Alabama in Huntsville, and his colleagues conducted the research.
Enveloped almost continuously by fog and mist, cloud forests are hotbeds of biodiversity, harboring innumerable plants and animals that are found nowhere else in the world.
In many regions, cloud forests are also a critical year-round source of clean water for people living in the surrounding lowlands.
But cloud forests are high on the list of the world's endangered ecosystems, Lawton and his colleagues warn.
"Cloud forests are very wet and very rainy, and people didn't want to live thereyou couldn't grow corn and beans there, for instance," Lawton said. "But increasing population pressure has forced people to slowly encroach on areas once considered uninhabitable."
"The most direct threats to cloud forests are land being cleared for farming," agrees Philip Bubb, a cloud-forest specialist with the World Conservation Monitoring Center and the United Nations Environment Programme. "In some cases, farm land erodes, so farmers move farther up the mountain."
In other regions, he added, mining and oil exploration, cattle ranching, and logging are threats.
Global climate change also could be a problem, said Bubb. A study two years ago in Nature, he pointed out, indicated that there may be a link between rising sea temperatures and clouds forming above the mountain tops, causing the forests to dry out.
Conservationists have been working to protect cloud-forest areas by establishing nature reserves. The findings of the new study suggest that this strategy is not enough to halt the loss.
"Conservation biologists in Monteverde have been quite happy and proud of what they've been able to protect, land that extends virtually all the way down the Pacific slope," said Lawton. "So it comes as a surprise to learn that the forests might be imperiled by what happens 100 kilometers (60 miles) downwind."
SOURCES AND RELATED WEB SITES