The Disappearing Clouds in a Costa Rican Cloud Forest

Photo via Wikimedia Commons

Evidence continues to grow everyday that global climate change is not only making the planet hotter, but it is also disrupting various ecosystems all over the world. In the U.S., Maine is grappling with the issues of ocean acidification and its effect on lobsters, which the state is so famous for. In the Tileran Mountains of northern Costa Rica, the Monteverde cloud forest’s clouds are disappearing.

Increasing temperatures, documented by bat biologist Richard LaVal, have caused clouds in the mountain forests to rise. LaVal’s study used data since the 1970s and found that the average temperature in Monteverde had jumped nearly 3 degrees Celsius in just a ten-year period, from 1990 to 2000. While temperatures have decreased in recent years, LaVal and researchers believe that the data indicates a long-term trend of increasing temperatures in the region.

Researchers are also concerned about the effects of the warming climate on the floral and fauna life in the cloud forest. Their data shows that species in the lowland, which are adapted to warmer temperatures, are moving into highland ecosystems where they are not traditionally found.

“We have at least 25 new bat species on the mountain from the tropical lowlands [that] are now here in Monteverde,” Vino De Backer, a Belgian zoologist who has worked with Laval, told Al Jazeera.

One such species, the Toltec fruit-eating bat, has retreated to even higher altitudes in order to find cooler temperatures than its native range, according to De Backer’s research. In the early 1970s, the Toltec bat accounted for 26.4 percent of total bats collected in Monteverde. Last year it accounted for only 19.5 percent. From the 1970s to 1990s, another highland species, the highland yellow-shouldered bat, has dropped almost in half—from 43.2 percent to 22.4 percent. At the same time, lowland bat species are moving into higher lands, which were the native range of bats like the Toltec. The Jamaican fruit bat—a lowland species—went from none in the 1970s to 12.6 percent of specimens caught last year.

Area farmers are experiencing problems caused by the rise of other lowland species of flora and fauna into the highlands. Oldemar Salazar Picado is a coffee farmer whose crops reside just below the Monteverde Cloud Forest Reserve. Al Jazeera reports that over the last two years, 80 percent of Picado’s crops have been destroyed due to the rapid proliferation of fungi.

“The bad thing about living on top of the mountain is that there’s nowhere to go,” biologist Dan Janzen told Al Jazeera, referring to the highland species that now must compete with lowland species that have moved higher to escape the increasing temperature. “You’ve created death valley for what lived above [the lowlands].”

According to the Monteverde Reserve, the Monteverde region is one of the most biodiverse places in the world: the area contains at least 3,200 plant species and 161 species of amphibians and reptiles and more than 400 birds and 100 mammals. As a result, the region hosts about 200,000 tourists each year, all looking for an opportunity to see some species that can be only be found in Monteverde.

With the famed cloud forest becoming cloudless, the effects on both tourism and the ecosystem look grim.