SANTA CRUZ, Bolivia (Reuters) - Forest fires that swept across Bolivia and Brazil this year could disrupt rainfall distribution across South America's grains-and-beef producing regions in unpredictable ways for years to come, a scientist and meteorologist said.
Recent rains in both countries have helped put out the wildfires, which were likely started by farmers and ranchers using slash-and-burn agricultural methods.
They have, however, destroyed large swaths of forest that lock in precipitation in the region, threatening a system of clouds known as "air rivers" in the Amazon that distributes 23 billion cubic meters of water across South America per year, said Leonardo Melgarejo, an agronomist with Brazil's Santa Catarina Federal University.
That might mean less rain in places that produce beef and soy in not just Brazil and Bolivia but also Argentina, Paraguay and Uruguay, said Melgarejo, potentially knocking a key driver of regional economic growth.
"The borders that divide our countries are fictions from the point of view of nature," said Melgarejo.
Destruction of just 5% more of the Amazon rainforest will trigger a worsening cycle of drought, fires and deforestation, Melgarejo said.
"We're very close to a moment of collapse," said Melgarejo told Reuters at a gathering of scientists in Santa Cruz, Bolivia, a lowland region hit hard by this year's fires.
German Heinzenknecht, weather specialist with the Applied Climatology consultancy in Argentina, said areas of the Pampas farm belt, including the provinces of Cordoba and Santiago del Estero, could be vulnerable to fallout from the fires.
"It is very possible that parts of northern Argentina will be affected by a delay in the start of the rainy season or that rains will be altogether less than normal. Everything depends on the area that is affected by the fires in Bolivia and Brazil," Heinzenknecht said.
Farmers were already concerned about dryness in Argentina's western farm areas before the fires. The country is a major exporter of soy, corn and wheat, and it is the top supplier of soymeal livestock feed.
A lot is hanging on the rains for Argentine farmers this season. A drought two seasons ago badly damaged crops, while favorable weather drove record harvests earlier this year.
Brazilian right-wing President Jair Bolsonaro and Bolivian leftist President Evo Morales, ideological opposites, have both been criticized for backing an expansion of soy and beef production in forested regions that environmentalists blame for the rash of fires this year. Both have downplayed the impacts amid the outcry.
Fires in Bolivia have swept over more than 5 million hectares, at least a two-decade record, according to Bolivian environmental group Friends of Nature Foundation.
Morales is up for re-election Oct. 20, with recent polls showing he may not have enough support to avoid a run-off vote for the first time ever.
Last week, Paraguay's parliament passed a resolution urging President Mario Abdo to ask Bolivia for compensation for damages to Paraguay's flora and fauna from fires lawmakers said started in Bolivia.
(Reporting By Monica Machicao; additional reporting by Hugh Bronstein in Argentina; Editing by Steve Orlofsky)
