Catching Fog in Peru's Coastal Desert

"If we can help generate alternative sustainable economic activities, we will be increasing the community’s chances for a viable livelihood in the face of climate change."

Juan José Rodríguez
The Nature Conservancy’s Coasts and Deserts coordinator

by Marcela Torres
Vea también en español

Have you ever seen a desert turn into a lush green valley bursting with life? This is exactly what happens in the coastal deserts of Peru every year, when oasis-like pockets of vegetation, called lomas, bloom between July and November thanks to the moisture they capture from fog. 

The lomas’ ability to capture fog and turn it into water that plants, animals and people can use is key to the survival of the biodiversity and human populations living in this otherwise arid environment.

But centuries of unmanaged livestock grazing and chopping of trees for firewood have left the lomas depleted, with less vegetation to capture fog the way they once could.

That’s why The Nature Conservancy and its partners are kicking off a three-year project in Atiquipa, Peru, to not only restore these important oases, but also to help local communities find ways to sustainably manage the lomas so they can continue to provide for people and nature year after year.  

How Does Fog Cover a Desert?

Three unique features coincide to form these rare desert oases:

  • Coastal deserts occur in Peru and Chile in a long sliver between the Pacific Ocean and the western slopes of the high Andes, which block moisture which would otherwise come from the east.
  • A large wind current called the Pacific Anticyclone blows dry air into the region.
  • The cold, northward-flowing waters of the Pacific Ocean’s Humboldt Current cool the air above the ocean surface and form clouds that produce a fine drizzle and fog that cover the coast up to an altitude of approximately 3,280 feet.

In Atiquipa, this fog’s advance is stopped by a series of rolling hills covered by desert vegetation that “capture” the fog to obtain moisture for survival, forming lush, green oases in the middle of one of the driest deserts in the world.

Who Needs Fog?

Ancient human populations in the area used to collect water that dripped from branches of native trees and cacti by placing containers underneath them. 

Nowadays, people place nets on top of these hills that actually catch the fog, and the condensation is then funneled into pipes and stored in underground containers. Sometimes the water is used to irrigate small farms; other times, for human consumption.

But without proper sustainable management measures in place, the ancient practice of water collection could disappear. If the lomas are completely deforested by grazing livestock, those unique plant communities will no longer be able to catch fog and send condensed water into the ground for other plants to grow and the desert will expand even more, particularly now that climate change is a threat due to the increase in temperatures.

That’s why the Conservancy is partnering with the Universidad Nacional San Agustín (UNSA) in Arequipa, the Yaku Allpa Association, the Atiquipa Rural Community Association, and the National Protected Areas Service to carry out a three-year project aimed at the conservation and ecological restoration of lomas and community-based management of natural resources in Atiquipa, which is a second phase for a previous initiative and will benefit 80 families, living in extreme poverty, that will gain access to double or triple the current amount of water obtained from fog-catching nets.

Part of the lands will be set aside to create a protected area, on community lands, and ensure the conservation of this fragile habitat. That’s why the Conservancy will also contribute to promote alternative ways to generate income without harming the environment by training locals as tour guides and service personnel (for transport, food and lodging) to develop ecotourism. Rodríguez explains that “unmanaged cattle grazing and informal mining are the main threats to this habitat. If we can help generate alternative sustainable economic activities, we will be increasing the community’s chances for a viable livelihood in this dry environment.” 

Why Protect the Lomas?

In 2007, the first regional conservation plan for Peru’s coastal deserts, conducted by the Conservancy and La Molina National Agrarian University, identified 7.5 million acres (approximately 3,035,142 hectares) as priority conservation sites, including the lomas in Atiquipa. The Conservancy knew something had to be done and decided to become involved in this new project that will help incorporate preserves in the lomas environment to Peru’s National Protected Areas System.

The area harbors close to 350 plant species, of which 44 are endemic to this environment, and is home to Peru’s best preserved lomas forest, composed mainly of native Arrayán (Myrcianthes ferreyrae) and Tara, or Spiny holdback, trees (Caesalpinia spinosa). Juan José Rodríguez, the Conservancy’s Coasts and Deserts coordinator, points out that “the Peruvian protected area service, SERNANP, is already working with us to create a protected area in Atiquipa, and the Arequipa Regional Government will establish a regional network of protected areas.”

Building on Past Experience

The project builds on previous and successful conservation and restoration activities carried out by UNSA with community participation. Percy Jiménez, researcher with UNSA and project leader, explains that “the University began work here in the 1980s, calling attention to the importance of this ecosystem, its condition and threats. By 1995, we managed to be heard and proposed a fog water supply project in the lomas.”

They obtained funds from the Global Environment Facility for the first part of the project that was carried out between 2002 and 2006 to restore and conserve the ecosystem, promote its sustainable use, and provide environmental education to the local community that owns the lands. By the end of the project, they had managed to place 3,533 acres (1,430 hectares) of lomas under community management to obtain water from fog-catching nets and use it to restore forest cover in the lomas. At the same time, 494 acres (200 hectares) of a pristine Tara forest patch were set aside for strict protection, in agreement with the Atiquipa Rural Community Association.

Phase Two Promises Even More

Juan José Rodríguez, the Conservancy’s Coasts and Deserts coordinator, explains that this second phase seeks to improve the efficiency of fog-catching facilities, which consist of nets that retain fog and release water that is collected in underground containers. 

The idea is to double or triple the current amount of water collected to 24-36 million liters per year. Part of the water will be used for human consumption, while the rest will be left to nurture the vegetation in the area being restored. Project leaders hope the efforts will enable the forest to reach its peak state.

The main goals of the project are to achieve the conservation of the area’s unique biodiversity and improve the quality of life for 80 families belonging to the Atiquipa Rural Community Association. According to Jiménez, “restoring forest cover will also allow an increase in the harvest of Tara seeds from new forest formations that will grow.” The Tara tree’s pods and seeds are an important source of income. The pods are used to produce tannic acid for high quality fur industry, as well as for the pharmaceutical, and chemical industries in domestic and international markets. From the seeds, people obtain gum that is used as a thickener in food for human consumption.


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