Cloud forests: narrow bands of biodiversity filled with mist, fog and mystery

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This story is part of the Landscape News series Forgotten Forests.

Hiking through the montane cloud forests of New Caledonia’s Mount Panié, fog often blinded Center for International Forestry Research director general Robert Nasi from seeing his own outstretched hands. “It’s very much an atmosphere of mystery: misty, rainy, generally cold, and not many animals, apart from small birds,” he recalls from past research journeys through the landscape. “It’s kind of this spooky feeling, where you know you are in a place where you don’t necessarily belong.” 

Cloud forests are born of very specific geographic and climatic features: they usually form partway up mountains, when moisture-laden air currents from surrounding lowlands and bodies of water are forced upward and then cool and condense as they rise, creating persistent fog or cloud cover in a particular area. The forests that grow there are often characterized by gnarled, stumpy trees; moss and lichen blanketing the ground and vegetation; strange, colorful orchids; and sodden epiphytes dripping water. It’s easy to see why these places are sometimes known as “goblin forests” or “elvin woodlands”: “They look a lot like some of the enchanted forests you see in The Hobbit and The Lord of the Rings,” says Nasi. 

But these woodlands’ real magic lies in their ability to conjure water “out of thin air.” Their canopy trees – and the plants that live on them – intercept wind-driven cloud moisture, which drips to the ground and soaks into their spongy soils, often providing a key water source for areas downstream. This water-capturing superpower means these moist forests can crop up even in the middle of deserts: the Fray Jorge cloud forest in northern Chile, for example, sits in an area that’s otherwise extremely arid, and survives almost entirely on the water that’s carried there on ocean breezes.  

Because of the particular conditions they require, cloud forests are usually quite small in size, and in total they make up just 1 percent of global forest area. There are 736 known cloud forest sites across the planet, in a broad range of locations across 59 countries: from 500-meter (1640-foot) altitude hillsides on Pacific Islands to sites at 4,000 metres (13,000 feet) above sea level in the Andes mountains of South America. 

While they’re not as species-rich as tropical lowland forests, cloud forests have high numbers of species that are found nowhere else on the planet, including eye-catching amphibians like the just-discovered, yellow-and-black-striped Ecuadorian rain frog (Pristimantis ecuadorensis); multitudes of mosses, ferns and epiphytes; rare birds such as the iridescently-plumed Resplendent Quetzal (Pharomachrus mocinno); and a handful of hardy mammals, including the Andean spectacled bear (Tremarctos ornatus).  

Life in the clouds

Like the rest of the world’s woodlands, cloud forests have been compromised and fragmented by timber felling, mining and land clearance for agriculture – we lose about 1.1 percent of the global cloud forest estate to these causes every year. For those that remain, it seems their strangeness and specificity has in some ways been their saving grace: they often inhabit “very steep, rocky and unfriendly places, with no real timber,” says Nasi, “and with climates that are too extreme for many human activities.” 

In Mexico, however, people have lived in and around cloud forests for millennia. In the highlands of Chiapas state in the south of the country, many Mayan communities call these peculiar places home – and rely on them for wood, wild foods and traditional medicines. When Tarín Toledo-Aceves, a tropical forest scientist at the Institute of Ecology in Mexico’s University of Veracruz and a 2020 National Geographic Explorer, travelled to Chiapas as an undergraduate researcher two decades ago, she was amazed by the multitude of ways that community members related to the forests there. “It’s almost like they bring the forest inside their houses,” she says. “They make these arches with the flowers from the epiphytic plants for celebrations, and if there’s a party, sometimes they’ll cover the whole floor of their houses with pine needles.” The forest was also the first port of call for curing illnesses, and local knowledge on this was incredibly in-depth: “It was like, every plant has at least five uses. If you boil it you can use it for this, and the bark can be used for that, and so on.”

These days, Toledo-Aceves lives on the cusp of a cloud forest herself, in the city of Xalapa, Veracruz, and she’s working on ways to help people co-exist more sustainably with these unique ecosystems. Many of Mexico’s cloud forests are now protected due to their high biodiversity, but illegal harvesting – for timber, firewood and charcoal – is still common. “The cloud forest has always been seen by the government in Mexico as an ecosystem that shouldn’t be touched, because it’s so valuable for its biodiversity, and because it’s so rare and so on,” she says. “But the problem is, if you don’t establish guidelines to manage them, then people will just do whatever. So sometimes forbidding is not the best way to conserve.”

That’s why Toledo-Aceves is working with communities to develop sustainable forestry management plans for some of the country’s secondary cloud forests (younger forests that have been logged and regrown), so that locals can legally log selected, high-value trees, while keeping enough of the canopy intact for the forests to remain and recover. She said the process has been challenging so far, as there is currently no classification for secondary forest in Mexican law, so any proposals have to follow all the compliance procedures for a mature forest. “And we did follow them, because I got money from a grant to do studies on this, but in general, people wouldn’t be able to afford them, and the volume of timber you are able to extract is so low that the cost-benefit ratio just doesn’t work out,” she says. “So we are trying to make proposals for modifying the legislation, so that these forests can be placed in a different category.”

Nowhere to go?

While projects like this might make an impact on ecosystems and communities at the ground level, a more existential threat looms large over the planet’s cloud forests: climate change. A 2019 study estimated that climate change could shrink and dry 60 to 80 percent of cloud forests in the Western Hemisphere in as few as 25 years. “These forests exist in a very narrow attitudinal range, and this altitudinal range is defined by the climatic condition,” says Nasi. “They can’t go down, they can only go up – which means that with the climate changing, the altitudinal range where they are growing is going to be narrower and narrower, until it finally disappears.” 

In Xalapa, those shifts are already being sharply felt. Two decades ago, the city was sheathed in mist and fog for about 240 days a year; now, as a result of both regional land-use change and global climate change, it’s more like 70 days annually. And as cloud cover dwindles, the forests surrounding the city are suffering. In many spots, there are few saplings to be seen, and the insects, amphibians, bats and birds that live there are also disappearing – either dying or migrating to higher, wetter locations.

To that end, the infectiously-optimistic Toledo-Aceves is now researching “assisted migration” for beleaguered cloud-forest inhabitants. “We’re trying to help species move to sites that, in the foreseeable future, might have the right conditions for them to thrive,” she said. For the past five years, she and her colleagues have been running experiments planting native seedlings in long lines up mountainsides, to see which ones survive at higher elevations. “And what’s beautiful is that we have had very high survival rates for many different species,” she says. “So that indicates to me that it is possible. Of course, there are plenty more components to the ecosystem that we still need to research. But I do think that there is a lot of hope.”