A small grove of huarango, the storied Peruvian tree that can live over a millennium, rests like a mirage amid the sand dunes on the edge of Ica, a Peruvian city. The tree has provided the inhabitants of this desert with food and timber since before the Nazca civilisation etched geoglyphs into the empty plain south of here about 2,000 years ago.

The huarango, a giant relative of the mesquite tree of the American Southwest, survived the rise and fall of pre-Hispanic civilisations and plunder by Spanish conquistadors, whose chroniclers were astounded by the abundance of huarango forests and the strange Andean camelids, like guanacos and llamas, that flourished there.

Today, though, Peruvians pose what might be a final challenge to the fragile ecosystem supported by the huarango near the southwestern coast of Peru. Villagers are cutting down the remnants of these once-vast forests. They covet the tree as a source of charcoal and firewood.

The depletion of the huarango is raising alarm among ecologists and fostering a nascent effort to save it.

“We don’t realise that we are cutting off one of our own limbs when we destroy a huarango,” said Consuelo Borda, 34, who helps direct a small reforestation project here, explaining how the tree’s pods can be ground into flour, sweetened into molasses or fermented into beer.

But many Peruvians view the huarango as prime wood for charcoal to cook a signature chicken dish called “pollo broaster.” The long-burning huarango, a hardwood rivalling teak, outlasts other forms of charcoal. Villagers react to a prohibition by regional authorities on cutting down huarango with a shrug.

“The woodcutters come at night, using handsaws instead of chainsaws to avoid detection,” said Reina Juarez, 66, a maize farmer in San Pedro, a village of about 24 families near a grove of huarango on the outskirts of Ica. “They remove the wood by donkey and then sell it.”

That the huarango survives at all to be harvested may be something of a miracle. Following centuries of systematic deforestation, only about 1 per cent of the original huarango woodlands that once existed in the Peruvian desert remain, according to archaeologists and ecologists.

Few trees are as well suited to the hyperarid ecosystem of the Atacama-Sechura Desert, nestled between the Andes and the Pacific. The huarango captures moisture coming from the west as sea mist. Its roots are among the longest of any tree, extending more than 150 feet to tap subterranean water channels.

The resilience of the huarango and its role in taming one of the world’s driest climates have long beguiled this country’s poets. Schoolchildren here, for instance, recite the words of Jose Maria Arguedas, a leading 20th-century writer: “The huarangos let in the sun, while keeping out the fire.”

But poetry is one thing. The necessities of human civilizations, and their capacity to wreak havoc on the ecosystems on which they depend, are another.

A team of British archaeologists described in a groundbreaking study this month how the Nazca, who etched their lines in the desert a thousand years before the arrival of the Spanish, induced an environmental catastrophe by clearing the huarango to plant crops like cotton and maize, exposing the landscape to desert winds, erosion and floods.

David Beresford-Jones, an archaeologist at Cambridge University who co-authored the study, said that perhaps the only fragment of old-growth huarango woodland left is in Usaca, about a five-hour drive from Ica, where there are still some trees that were alive when the Incas conquered the southern coast of Peru in the 15th century.

“It takes centuries for the huarango to be of substantial size, and only a few hours to fell it with a chainsaw,” Beresford-Jones said. “The tragedy is that this remnant is being chain-sawed by charcoal burners as we speak.”

With support from Britain’s Royal Botanical Gardens at Kew and Trees for Cities, a British charity promoting tree planting in urban areas, Borda’s reforestation project seeks to reverse the damage by the charcoal harvesters, whose mud ovens dot the desert landscape in villages around Ica.

It is an uphill struggle in an impoverished desert. The black market for huarango in raw firewood form thrives. A carbonero, or charcoal seller, can sell a kilogram of charcoal made from the tree for about 50 cents, or a bushel of huarango as firewood for about $1 — bargains in a place where a gallon of natural gas costs more than $10.

So far, Borda’s arduous project has planted about 20,000 huarangos in Ica and nearby areas. It also teaches schoolchildren about the history of the huarango in Peruvian culture and its significance as a keystone species for the desert, its roots fixing nitrogen in poor soil and its leaves and pods providing organic material as forage.

But researchers say the project is a trifle of what must be done to reforest Peru’s deserts.

“Peru needs a massive rethink about its development trajectory,” said Alex Chepstow-Lusty, a paleoecologist with the French Institute of Andean Studies who worked on the Nazca study with Beresford-Jones, the Cambridge University archaeologist, analysing pollen that showed the transformation of Nazca lands from rich in huarango to fields of maize and cotton to the virtually lifeless desert that exists today.

“With Peru’s glaciers predicted to disappear by 2050, the Andes need trees to capture the moisture coming from Amazonia, which is also the source of water going down to the coast,” said Chepstow-Lusty in an interview from Cuzco, in Peru’s highlands. “Hence a major program of reforestation is required, both in the Andes and on the coast.”

Nothing on this scale is happening around Ica. Instead, the growth that one sees in poor villages are of shantytowns called pueblos jovenes, where residents eke out a living as farmhands or in mining camps.

Outside one village, Santa Luisa, the buzz of a chainsaw interrupted the silence of the desert next to an oven preparing charcoal.

The chainsaw’s owner, a woodcutter from the highlands named Rolando Davila, 48, swore that he no longer cut down huarango but focused instead on the espino, another hardy tree known as acacia macarantha. “But we all know huarango is the prize of the desert,” he said. “For many of us, the wood of the huarango is the only way to survive.” — © 2009 The New York Times News Service

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