The first thing I notice about the cloud forest is its lovely, gentle sound. I walk along a path narrowed by trees and moss-covered rock and hear the light whisper of water, faint but constant. It is a soothing sound, but rather than white noise, I’d say it’s more like silver, or crystal, such is its brightness and fragility. Indeed, this high-montane forest preserve has a crystal-like name: Joya del Hielo, which roughly translates to Jewel of Ice. ‘Ice’ because the temperature is always cool. Here, in central Mexico’s eastern Sierra Madre Mountains, the mist and the high altitude guard the chill. At least they do for the time being. Alas, nearby logging and land clearances making way for farms and pastures are altering the humidity up in the hills.
My guide today is Roberto Pedraza Ruiz, a naturalist and prize-winning photographer. In 1987 his mother, Martha ‘Pati’ Ruiz Corzo, co-founded the Grupo Ecológico Sierra Gorda, a conservation and education organization that protects the cloud forest enclave. Pati, once a high-heel-wearing music teacher during her city years, lives in a small mountain cabin surrounded by ancient sweet gum trees. She is short and stout and fierce; she is driven by a passion for the earth and its ‘beauty-ness’. I have watched her stand before legislators at the Mexican Senate in a drab brown tunic and rubber-treaded sandals and move the formally attired officials to tears, laughter and song. In 1997, through sheer determination and a refusal to keep quiet, she managed to convince the state of Querétaro to declare one third of its land – some 383,567 hectares – a biodiversity reserve.
The headquarters of the Sierra Gorda alliance is an education and training center in the town of Jalpan de Serra, a three-hour-plus drive from Querétaro airport where Roberto picks me up. The last stretch rising into the hills is one of the most dizzying experiences found outside an amusement park: switchback after switchback, swerving away and then driving directly at the sun. (Roberto had recommended Dramamine.) At some point we start passing over and through the clouds. Sometimes the mist thins out, revealing purple and red mountain flowers and bushes with yellow blooms. Sometimes I can see only the ghostly silhouettes of trees.
The road glistens and the leaves on the trees are wet; pines droop under the weight of moisture clinging to needles. It is early March and the rainy season doesn’t start until June, Roberto says, emphasizing that the dampness is from the humidity alone. Roberto, who is now in his mid-forties, says that when he was growing up the rain was soft and light, but in recent years it has come in heavy and sudden downpours. Today Roberto is happy to be driving amid clouds. ‘The cloud forests have been stressed,’ he says. ‘It’s been a dry winter.’
The route to Joya del Hielo the next morning is also zigzagging, but not vertiginous like the airport run. Roberto watches out the window for birds and reports on what he sees: clay-colored thrush, oriole, woodpecker, kestrel. ‘This area is a stronghold for bearded wood partridge,’ he says, referring to a long-tailed forest fowl with a red beak and breast the color of cinnamon. ‘I haven’t been able to photograph it – that’s a big frustration in life. I saw one with chicks and made a call, but they were too quick.’ On another occasion he and a film team finally gave up on one and left the site at 2 a.m., only to return the next day to find it had shat on their equipment. Roberto frequently arranges for photographers and film crews to visit Joya del Hielo. A few years ago the BBC came to get footage of the bumblebee hummingbird, the world’s second-smallest hummingbird, which weighs less than a penny.
After bumping along a dirt road for a few minutes we arrive at the edge of the cloud forest reserve and are greeted by a fallen tree crossing and obstructing our way into Joya del Hielo. It proves too heavy to move. Roberto dispatches his chainsaw, and after getting through and driving for another kilometer, we get out and leave the car. I grab a notebook and my water bottle. Roberto shrugs. ‘I don’t need water in the cloud forest,’ he says. He grabs his camera and a machete.
As we walk, Roberto points out jaguar scat and the spot where a puma and jaguar had a fight; the forest is home to all six of Mexico’s feline species. Life appears in layers. Spiky bromeliads – in Roberto’s words, ‘flats for frogs and salamanders’ – jut out from the trunks of hardwoods, while cacti are growing in the nooks of trees. Flowering carnivorous plants, with sticky leaves able to catch and digest insects, grow on limestone. Roberto peers up at a large oak tree where various orchids reside. ‘There’s a whole ecosystem on that one,’ he says. Further on we pause at another large, grand oak, clothed in mist. ‘This is the king of the forest,’ says Roberto. ‘His “brother” passed away six years ago in a storm. The former owner of the land said, “How much charcoal can be made from that?” ’
The abundance of life in the cloud forest is stunning. Everywhere you look life is dripping, climbing, crawling, dangling, hiding, sprouting from, nesting on, nestled in. ‘Those are 500- to 600-year-old cedars,’ Roberto says. ‘I don’t know why they spared them.’ He notes that the previous owner was known to log with impunity.
Some 200 meters past the cedars, we reach an area where Roberto has identified three previously unknown species of magnolia, two of which have been found only in this forest. (One variety is named for him: Magnolia pedrazae.) He calls magnolia ‘living fossils’, since they are considered earth’s first flowering plants. This section of the cloud forest, at 2,000 meters above sea level, is a nursery for rare magnolia trees. Now that they are known to be here, and are protected from chainsaws and browsing cattle, the magnolia population is rebounding. When they bloom, the fragrance suffuses the whole forest, Roberto says. ‘Here’s a young one. There is hope for the species. When you look closely, nothing here is alone.’
The thing about water is that it depends upon water. When land in the area below Joya del Hielo is cleared of vegetation for farming and firewood, this means less water circulating in the vicinity, a key aspect of what Roberto calls stressors to the cloud forest. If the lowland dries out, it becomes that much more difficult for a higher-altitude forest to make a cloud. Moisture in one place informs moisture elsewhere. As the late poet Tony Hoagland wrote in ‘The Social Life of Water’, ‘All water is part of other water. / Cloud talks to lake; mist / speaks quietly to creek.’ Similarly, the loss of water in one location can have the effect of drying out another. For example, depleting an aquifer for irrigation wells, as is happening across North America’s agricultural lands, lowers the water table so that nearby streams and wetlands dry out and wildlife has no place to go. As many of us who’ve seen these patterns playing out have realized, aridity is contagious.
When rain soaks in and is held in the soil, the area stays moist and covered in plants. When the surface is exposed, water evaporates or runs off, leaving the land parched and, in certain environments, prone to fire. Climatic conditions are largely determined by how water circulates, how it moves across the landscape and through the air. Water problems like floods and droughts are often symptoms of climate change, but supporting the water cycle can help regulate and moderate temperature. To a large extent, the story of climate is the story of water.
Plants, particularly trees, are central to the wetting or drying of a landscape. For one, trees embody water. According to Andy Lipkis of TreePeople, an NGO in Los Angeles, the root system of a mature tree can retain tens of thousands of liters of rainwater. Bill Mollison, the late Australian scientist and early teacher of permaculture, which applies insights from nature to farming and design, said ‘a tree stands there as a barrel of water’. Trees are also continuously putting moisture back into the environment. With their vast green surface area, they hold and evaporate water. More significantly, they transpire, as water moves up from the roots and out through the leafy canopy. A good-sized tree can transpire 400 liters of water each day.
You can think of a plant as a water pump, pulling moisture from the surrounding soil and releasing it as vapor. From the plant’s perspective, this process is vital for regulating its own temperature because transpiration is a cooling mechanism, in that it consumes energy. Turning liquid water into a gas not only uses energy, it also dissipates the heat beaming down from the sun. Solar energy hitting a bare surface – think midsummer tarmac – creates ‘sensible heat’, or heat you can feel. If instead that radiation falls on vegetation, thanks to transpiration it becomes ‘latent heat’, suspended in the water vapor through space and through time. This is one reason Joya del Hielo feels so cool: those plants that fill every available niche are busy transpiring, which postpones the unleashing of heat and ensures it remains in the realm of potential.
In the aggregate, as forests, trees are moving around tremendous amounts of moisture, and therefore energy. In 2015 I spoke with Brazilian scientist Antonio Donato Nobre, who described forest-driven ‘aerial rivers’: bodies of moisture that sail, unnoticed, through the sky. He said airborne waterways above the Amazon rainforest contain more water than the mighty Amazon River below, as twenty metric tonnes of water flow out from the trees and into the air. The notion of water continuously floating above the earth reminds me of the Hebrew word for sky, which is shamayim, or ‘there is water’. I had always found this curious. Likewise, in her essay ‘Clouds’, Rachel Carson writes: ‘Up there is another ocean – the air ocean that envelops the whole globe.’
Antonio Nobre likes to say, ‘Every tree is a geyser.’ To a large extent weather comes down to the agency of trees. Trees cast out moisture, but they also pull it in. According to a theory called the biotic pump, the cumulative transpiration of trees in a forest forms a low-pressure zone which creates a vacuum that draws in moisture. This laden air cools and condenses over the forest, and we have rain. A healthy forest is at once generating its own rain – that soft, crystalline song in Mexico – sending water abroad and tugging water in from elsewhere. It is a dynamic system, as moisture both rides the current and creates it. Trees and clouds are talking to each other.
Past a certain threshold, however, tree loss interrupts the dialogue. This worries Roberto Pedraza Ruiz, who says that a patchwork of small, protected forests does not function in the same way as a large wooded expanse. Meanwhile, it has been four years since I interviewed Antonio Nobre and encountered his poetics of the rainforest: seeing thick, extensive forest as a ‘green ocean’, with waves of humidity lofting over and across. What seemed eternal now feels unnervingly provisional since the world has, with appropriate horror, witnessed the relentless felling of trees in the Amazon basin in the last two years.
That deforestation leads to drought and even ecological collapse should be news to no one. The demise of civilizations like the Mayans, Anasazi, Easter Islanders and (at least in part) of Rome offer a cautionary tale. Alexander von Humboldt, a naturalist and adventurer born in 1769, wrote that cutting trees on hillsides ‘seem[s] to bring upon future generations two calamities at once; want of fuel and a scarcity of water.’ In his 1864 book Man and Nature – original title: Man the Disturber of Nature’s Harmonies – George Perkins Marsh, the nineteenth-century diplomat and scholar whom many consider America’s first environmentalist, wrote of the need to restore forests to ‘devise means for maintaining the permanence of its relation to the fields, the meadows and the pastures, to the rain and the dews of heaven, to the springs and rivulets with which it waters the earth’.
Back to the Amazon basin: at what point will the trees and the clouds stop communicating? How many more blows of the ax before the great, damp inhalations and exhalations, the sources of moisture for so much of the hemisphere, are stilled?
They say every snowflake is unique. I would venture every snowfall has its own signature as well. Today’s is coming down in clumps, as if some prankster were tossing dampened wads of tissue from a great height. Sodden November snow like this creates definition: it clings to surfaces, so as to add an outline to every limb and vine it lands on. The effect is something like the Japanese woodblock style called ukiyo-e, also known as ‘pictures of the floating world’. By mid-morning the temperature is above freezing. The air is so thick with white that it’s hard to pinpoint exactly when the snow stops.
My friend Jim Laurie, a sort of freelance ecologist and educator based near Boston, likes to come up to Vermont and walk in the snow. He’ll point out tiny snow fleas – a kind of springtail – and where the beavers have been. For many years Jim had a job at a Texas chemical plant. There he experimented with ways to remediate water with sunlight, air and microorganisms: the effluent moves through a series of tanks seeded with microbes from different ecosystems and emerges pristine. He later worked with ecological designer John Todd to develop the Eco-Machine, a ballroom-sized installation that mimics natural environments like streams, ponds and marshes, to yield clean water. Through the 1970s and 1980s Todd was associated with the New Alchemy Institute, known for pioneering research into biological models for energy, farming and shelter. While using plants, aquatic creatures and sunlight to purify water sounds like a kind of alchemical magic, this is what nature does.
On a recent visit Jim explained to me that water, by its very nature, has a tendency to affiliate. This is because H2O, the water molecule, is polar: with one end positive and the other negative (the hydrogen and oxygen sides, respectively), one water molecule is drawn to another, as with a magnet. He referred me to Nobel laureate Richard P. Feynman’s observations on how atoms ‘jiggle’ and interact. In a 1983 interview, the theoretical physicist said that within a drop of water ‘the atoms attract each other. They like to be next to each other. They want as many partners as they can get.’ Even on a microscopic level, water seeks company.
Spanish meteorologist Millán M. Millán has a saying: ‘Water begets water, soil is the womb, and vegetation the midwife.’