Chile: Sol Survivors
Writer Rianna Riegelman finds out that there is life in the driest part of the world.
Most depictions of the Atacama are of a bone-dry, lifeless and barren desert uninterrupted by a stem of green for miles and miles in the merciless scorching sun. This is what I imagined when I first ventured there and, at first glance, this is what I saw. As I became more intimate with life in the desert it didn’t take long for me to realize that there is, in fact, life in the desert!
The Atacama Desert stretches south from the Chilean border with Peru for about 600 miles (960 km) with an area of approximately 70,000 square miles (180,000 sq km).
In such a vast area, conditions vary significantly. Some corners of the Atacama report no recorded rainfall –ever– and support no life. In fact, a 2003 issue of Science magazine described soil samples taken from an especially arid region of the Atacama Desert that were so lifeless and void of all but trace organic or bacterial matter that they were compared to soil samples taken by the Viking mission on Mars. Other parts of the Atacama receive regular seasonal rainfall and support a variety of vegetation, some wildlife, and even human agriculture.
Believe it or not, the Atacama Desert hosts more than 1,300 native plant species. Approximately 60% of those are believed to be endemic to the region. The highest concentration of plant species in the Atacama is located in the south and along the coast. Much of the interior desert in the north lives up to the Atacama’s reputation for being a dry and lifeless wasteland of sand and sun. However, wherever there is even a drop of moisture, there is life. Plants in this region receive moisture in one of three major ways: from underground water stores, coastal fog, and periodic rainfall events.
Underground Water
The Atacama is a rain shadow desert with unique geography. Most of the westward-bound moisture that would fall over the Atacama gets caught up in the lofty heights of the Andes, cools and falls on the Eastern side of the mountains, draining into the giant Amazon River Basin. The land on the western side of the Andes is characterized by vast salt and mineral fields bordered on the east by the Andes and the west by a coastal range that rises rapidly from sea level up to more than 3,000 feet (900m). In the wide valley between the two mountain ranges, underneath the mineral flats, are ancient stores of water – glacial melt from a former ice age that was denied drainage by the geographical barriers of the rising mountain ranges.
One northern native desert tree seems to have been designed especially to take advantage of these ancient underground water sources. Prosopis tamarugo, a mesquite tree known as tamarugal in Chile, sends long taproots deep into the ground to be nourished by underground springs. Native tamarugal trees were nearly driven to extinction by overuse for fuel and are threatened further by the lowering of the water table due to industrial use. Reforestation is very difficult because younger tamarugal do not have the longer, established taproots that they need to access the underground water sources, making it even more important that older species are maintained and protected. In 1987, the Pampa de Tamarugal National Reserve was established about 45 miles (70km) east of Iquique to protect the last remaining stands of native tamarugal in the Atacama.
Camanchaca
Life on the coastal slopes of the Atacama is not quite as desperate as it is on the high plain. Coastal conditions are relatively consistent: the Humboldt Current, which travels north from Antarctica, introduces cool temperatures to warm, humid sea air, causing most of the moisture to be released offshore. The little moisture that does remain suspended in the air usually gets hung up in the ‘fog corridor’ around 1,000–2,000 feet (300–600 meters) above sea level, unable to penetrate the coastal range to dissipate over the interior desert. The special type of fog that these conditions create is known in Chile as camanchaca. Camanchaca is a big part of life in coastal desert cities. You can see restaurants and boats named fondly for this life-giving natural force in towns along the northern Chilean coast. Camanchaca is an important water source for many coastal plants such as endemic cactus and bromeliad species. Eulychnia iquiquensis is an endemic cactus that can be found clinging to the high slopes of the northern coastal range. Tillandsia landbeckii, is a bromeliad that can be seen in dusty groupings on hills or lomas along the fog corridor of the coastal-facing slopes of the northern desert. Copiapoa cacti are a favorite of the southern Atacama coast. Each of these plant species depends primarily on coastal fog for moisture.
Following the model of fog-catching plants, humans have also successfully cultivated camanchaca. An experimental fog-collecting project in the early 90s in the northern Chilean coastal village of Chungungo proved a technical success. At the project’s peak, 94 mesh fog collecting nets were harvesting 4,000 gallons (15,000 liters) of water per day for the village’s 300 or so inhabitants allowing them to freely use water for agriculture, drinking, and bathing. It is not fully understood why the fog collection method was not permanently embraced by the village, but most point to reasons of culture rather than technical problems in the collection process. Fog collecting projects based on this experiment have flourished in other parts of the world.
Oasis Agriculture
Along the Atacama’s coastal range, deep valleys and dry river beds cut down from the high desert toward the sea. Some of these valleys receive enough seasonal rainfall or run-off from the high desert plateau (known as the Altiplano) to sustain oasis villages. People, animals, and plants flock to these desert oases. Some oasis villages, like Pica, have enough water to practice agriculture. The tasty mangos, limes, and strawberries of Pica can attest to the effectiveness of oasis agriculture. Underground springs in the northern oasis town of Mamiña run both hot and cold, giving the village a small hot springs tourism industry, as well as a water bottling plant. The oasis town of Azapa near Arica is famous for the cultivation of olives. In the southernmost Atacama, where the climate is semi-arid, crops such as papayas, avocados, and the sweet grapes used in Chile’s national drink, Pisco Sour, are grown with great success in valley communities, such as Valle de Elqui.
Blooming Desert
Perhaps life in the desert is most spectacularly seen in the phenomenon of the blooming desert or desierto florido. In the southern stretches of the coastal Atacama, millions of seeds lie patiently dormant in the sand waiting for a rainy day. During years with a high increase in rainfall – usually years with El Niño weather events – those seeds explode into a desert confetti of red, orange, yellow, blue, and purple. Tourists as well as academics and floral enthusiasts flock to Llanos de Challe National Park, Paposo National Reserve, Pan de Azucar National Park and other areas near Vallenar and Copiapo, Chile to view the natural spectacle, which occurs roughly every four to five years. These parks and reserves were created to protect the hundreds of endemic plant and flower species that can be found within their borders. Of particular value and fondness are the beautiful Leontochir ovallei, known locally as Garra de Leon or Lion’s Paw, which grow only in this unique eco-region. More than 200 other floral species show up during years with major rainfall events, many with endearing nicknames such as suspiro or ‘whisper’ (Nolana elegans) and pata de guanaco, ‘guanco’s paw’ (Calandrinia longiscapa), to cover the once rocky desert in a cheerful carpet of color.
Life in the desert is not easy and the margin of survival is thin. Plants of the Atacama Desert have naturally adapted to their harsh surroundings in ways that humans continue to struggle to do with as much success. These rugged and beautiful plants breathe life and character into the solitary desert and present an inspiring model of resource efficiency.
Further Reading:
www.chileflora.com - Photo identification and descriptions of plants of Chile
www.atacamaphoto.com/atacama-flora/desert-flora-1.htm - Beautiful photo gallery of blooming desert (desierto florido) by photographer Gerhard Hüdepohl
Rianna Riegelman is a restless Colorado native who loves exploring new places and sharing what she finds and what finds her. Recent homes have included a 4th floor walk-up on a sweet tree-lined block in Brooklyn, a shipping container at the base of a sand dune in the Atacama Desert, and a very practical Swiss-designed one-man tent inhabited by two people in Patagonia.
Sources:
Navarro-Gonzalez et. al. “Mars-Like Soils in the Atacama Desert, Chile, and the Dry Limit of Microbial Life”
Science 7 November 2003: Vol. 302. no. 5647, pp. 1018-1021.
https://www.sciencemag.org/cgi/content/abstract/302/5647/1018
Dale, Stephen. “Collecting Fog on El Tofo” International Development Research Centre
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