At least 1.2 million acres of the Chaco have been deforested in the last two years, according to satellite analyses by Guyra, an environmental group in Asunción, the capital. Ranchers making way for their vast herds of cattle have cleared roughly 10 percent of the Chaco forest in the last five years, Guyra said. That is reflected in surging beef exports.
“Paraguay already has the sad distinction of being a deforestation champion,” said José Luis Casaccia, a prosecutor and former environment minister, referring to the large clearing in recent decades of Atlantic forests in eastern Paraguay for soybean farms; little more than 10 percent of the original forests remain.
“If we continue with this insanity,” Mr. Casaccia said, “nearly all of the Chaco’s forests could be destroyed within 30 years.”
The rush is already transforming small Mennonite settlements on the Chaco frontier into boomtowns.
The Mennonites, whose Protestant Anabaptist faith coalesced in Europe in the 16th century, founded settlements here in the 1920s. Towns with names like Neuland, Friedensfeld and Neu-Halbstadt dot the map.
Buoyed by their newfound prosperity, the Mennonite communities here differ from those in other parts of Latin America, like the settlements in eastern Bolivia where many Mennonites still drive horse-drawn buggies and wear traditional clothing.
In Filadelfia, Mennonite teenagers barrel down roads outside town in new Nissan pickup trucks. Banks advertise loans for cattle traders. Gas stations sell chewing tobacco and beers like Coors Light. An annual rodeo lures visitors from across Paraguay.
Patrick Friesen, communications manager for a Mennonite cooperative in Filadelfia, said property prices had surged fivefold in recent years. “A plot of land in town costs more than in downtown Asunción,” said Mr. Friesen, attributing the boom partly to surging global demand for beef.
“Eighty-five percent of our beef is exported, to places including South Africa, Russia and Gabon,” he said. Citing concerns in some countries over foot-and-mouth disease, which Paraguay detected in its cattle herd in 2011, he continued, “We are currently focused on some of the less-demanding markets.”
Paraguay’s Chaco forest lies in the Gran Chaco plain, spread across several nations. Scientists fear that the expansion of cattle ranching could wipe out what is a beguiling frontier for the discovery of new species. The Chaco is still relatively unexplored. The largest living species of peccary, piglike mammals, was revealed to science here in the 1970s. In some areas, biologists have recently glimpsed guanacos, a camelid similar to the llama.
More alarming, the land rush is also intensifying the upheaval among the Chaco’s indigenous peoples, who number in the thousands and have been grappling for decades with forays by foreign missionaries, the rising clout of the Mennonites and infighting among different tribes.
One group of hunter-gatherers, the Ayoreo, is under particular stress from the changes. In 2004, 17 Ayoreo speakers, from a subgroup who call themselves the Totobiegosode, or “people from the place where the collared peccaries ate our gardens,” made contact with outsiders for the first time.
In Chaidi, a village near Filadelfia, they described being hounded for years by bulldozers encroaching on their lands. The Ayoreo word for bulldozer, “eapajocacade,” means “attackers of the world.”
“They were destroying our forests, generating problems for us,” one Totobiegosode man, Esoi Chiquenoi, who believed he was in his 40s, said through an interpreter. As a result, he and others in his group, who in photographs taken in 2004 were wearing loincloths, abruptly abandoned their way of lif