News•December 8, 2012

Colombia's Cloud Forests Besieged by Climate Change

ANTIOQUIA, Colombia – Five hours by truck and mule from the nearest town, a rumbling generator cuts through the silent night to power large spotlights as botanists crouch and kneel on large blue tarps spread across a cow pasture. It's nearly midnight, and the team works urgently to describe every detail of the dozens of colorful orchids, ferns and other exotic plants they have collected that day in Las Orquídeas National Park, one of the single most biologically diverse places on the planet.

For nearly two weeks, each day begins and ends like this. At 6 a.m., the botanists emerge from their tents, just before the sun peeks over the mist covered mountains. They down a breakfast of cornmeal arepas and steaming bowls ofagua de panela, a local drink made from boiled sugar cane. Then they don their rain gear, cross the river on a dubious bridge made of a single log and trudge along narrow, muddy trails before fanning out into the cloud forest.

The Andean cloud forest in Colombia is one of the most biologically diverse areas in the globe. Scientists are racing to document a baseline before the area changes as a result of global warming and development.
Credit: Autumn Spanne.

Their mission: To collect as many species of flowering plants as possible and return to base camp before heavy afternoon rains swell the river to dangerous levels. They're racing a different clock, too. Climate change and development are beginning to erase these irreplaceable ecosystems. The researchers are scrambling to understand what is here before it disappears.

The scientists are carrying out a three-year project, funded by the U.S. National Science Foundation, to create a comprehensive inventory of all the vascular plants in this park. It's a considerable undertaking. At least 3,000 plant species — including the more than 200 species of orchid for which the park is named — are believed to inhabit Las Orquídeas. Potentially hundreds of plants have yet to be identified by science.

Biodiversity hotspot

What makes this park in northwestern Colombia a global biodiversity hotspot is its location at the intersection of the Chocó and the Tropical Andes, two of the richest biogeographic regions in the world. But for the better part of two decades, Las Orquídeas, like many other ecologically important areas in Colombia, was largely off limits to scientists because portions of the park had become the unofficial territory of armed groups in the country's decades-long conflict.

All over the mountain tropics of South America, the race is on identify unique, often endemic species before natural resource exploitation and climate change converge to threaten them. Before scientists can document the impacts of climate change, they must be able to establish a baseline for how these ecosystems function. But in Colombia, which may have the greatest biodiversity of any country on earth, research is often decades behind; field expeditions can be dangerous, making funding hard to come by.

Las Orquídeas is home to more than 200 species of orchid.
Credit: Autumn Spanne

Today, the Colombian government is holding peace talks with the largest rebel group, the Revolutionary Armed Forces of Colombia, or FARC, and the conflict has retreated from Las Orquídeas over the past several years. Yet the high mountain ecosystems of the Colombian Andes remain besieged. As the country becomes more secure, mining, timber, agriculture and ranching are expanding rapidly, leading to massive deforestation and contributing to temperatures that are rising significantly faster than at lower altitudes.

“The Andes is actually the most diverse region of the planet,” said Paola Pedraza-Peñalosa, a Colombian botanist at the New York Botanical Garden who is co-leading the Las Orquídeas research. “Here we have a great diversity of plants that has no parallel in the rest of the world, but also the Andes is one of the most deforested areas.”

Dual impacts

Like coral reefs and glaciers, the tropical Andes are among the most vulnerable to the dual impacts of climate change and human population pressures. About a sixth of the world's biodiversity — perhaps two million species of plants, animals, fungi and microorganisms — can be found in the region. About 10 percent have been identified.

“What makes the northern Andes so special is that they have extraordinary concentrations of species within very small geographical ranges,” said Stuart Pimm, a professor of conservation ecology at Duke University who specializes in species extinction.

“Each one of these mountain-tops has wonderfully different sets of species of plants and birds and butterflies and amphibians,” said Pimm, who also chairs a conservation organization, SavingSpecies, that is restoring deforested lands near Las Orquídeas to address habitat fragmentation. “The question is, what happens when the climate warms?”

The vast range of ecosystems in the park begins in lowland rain forests 2,600 feet above sea-level, rising to mountain cloud forests and then páramo wetlands at an elevation of more than 11,000 feet, where fog clings to the chilly slopes and spongy moorland valleys just below glacial peaks.

“Sometimes you think about how long these things have been out there and we are just not getting to them on time, in that the deforestation is happening sometimes in front of our eyes and things that are not even known to scientists ... are disappearing,” said Pedraza-Peñalosa.

Specific niches

Plants and animals in the tropical Andes have evolved to fill specific niches up and down the mountains. In Las Orquídeas, those species include the emblematic and endangered Andean spectacled bear, rare jaguar, puma, monkeys, deer, amphibians and an incredible variety of birds, bats and insects.

Credit: Autumn Spanne

Throughout the tropical Andes, the habitats of these animals are already fragmented by deforestation. Climate change could exacerbate those changes, according to Orlando Vargas, a professor of ecology at the National University of Colombia in Bogotá.

Vargas is monitoring the impacts of climate change in páramos like Chingaza, near Bogotá. He notes two distinct trends in these high mountain ecosystems as human pressures converge with rising temperatures and other global climate disruptions.

One is that plant species from lower elevations are migrating up the mountains, threatening to transform the unique ecosystems of the cloud forests and the páramos. The second, and perhaps more serious problem, he said, is the upslope encroachment of invasive plant, animal and insect species. These invasive species can often move faster than native plants, pushing out species critical to the integrity of the upper mountain ecosystems.

That problem is made worse by the fact that human interventions have reduced predators and, in doing so, increased the populations of the animals they once preyed on. While these animals are not invasive species, they behave like them, said Vargas, consuming plants and other animals that maintain the healthy functioning of the ecosystems.

Shifts in seasonal events such as plant bloom times could cause additional significant disruptions, he said.

Species react

But it's not always clear how species will react to warming temperatures, according to Pimm, who is investigating whether climate change will directly lead to the extinction of species, or just add to the threats they face.

The Colombian Cloud forest.
Credit: Stuart Pimm

“Estimates for climate-related extinctions are all over the place,” he said. “There is no consensus, and we need to have better answers.”

The lack of information creates obstacles for those tasked with creating effective conservation strategies in the region's protected areas. Héctor Velásquez Lema, the director of Las Orquídeas, said park managers often work with very limited information and resources.

Simply having baseline data on plant populations is a significant step in improving conservation plans for these complex ecosystems. But Velásquez Lema is concerned about the dearth of research on how climate change could compound existing problems created by ranching, agriculture, mining and timber harvesting in and near his park.

As in much of the Andean region, national parks in Colombia are not solely for recreation and conservation. Poor campesino farmers and indigenous communities exist within the boundaries of protected areas, often surviving by clearing forests for small-scale cattle ranching and cultivating crops like sugar cane, corn and potatoes. Some practice small-scale gold mining — illegally, or with government permits granted before the park existed.

Mining impacts

Velásquez Lema also worries about the impact of large-scale mining and logging by national and multinational corporations just outside of protected areas like Las Orquídeas, which degrades ecosystems and leads to the fragmentation of habitat. Over 74,000 acres of land in Antioquia, the department, or state in which Las Orquídeas is located, get deforested every year, he said. Combined with global climate change that disrupts weather patterns and increases temperature, these industries could spell disaster for already vulnerable species.

The endangered spectacled bear is one such species. It feeds primarily on plants at high altitudes but migrates through different elevations within the park in search for food. Velásquez Lema wonders what will happen if seasonal patterns shift and bears aren't able to find their usual food inside the forest. They might starve, or they might come into conflict with populated areas as they search for food. Rare jaguars, already facing fragmentation of their habitat due to deforestation and industry like mining, face similar threats to their survival.

“Things are always interconnected, and that is why climate change is something we should worry about,” said Velásquez Lema. “We are all connected in the fabric of life and there are consequences for the things that happen here that will affect humanity in general.”

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