Brought in by humans, beavers threaten Patagonia forest in Chile


TIERRA DEL FUEGO, CHILE (AFP) – The Karukinka natural park on Chile’s side of the Tierra del Fuego archipelago guards a treasure trove of ancient beech trees saved from the chainsaws of loggers.

Today, the leafy giants face a new threat: a flourishing community of beavers brought to Patagonia from Canada 75 years ago with the idea of promoting human settlement, centred on fur trade, on the sparsely populated tip of South America.

While the pelt project never really took off, the beavers did.

The first 10 pairs introduced to the area have become more than 100,000 individuals.

And a single rodent has enough gnawing power to fell a tree that took a century to reach maturity in just a few days.

“Beavers, just like humans, are ecosystem engineers… In order to inhabit an environment, they modify it to adapt to the conditions they need to survive,” Cristobal Arredondo, a researcher at the Wildlife Conservation Society (WCS), told AFP.

In so doing, the beavers have wreaked havoc on the 300,000 ha park.

The beavers chew down trees to build dams in rivers and lakes, but now in a part of the world where the forests regenerate much slower than in their native North America.

The dams also cause a secondary harm – flooding the soil the beeches grow in and drowning them from the roots up.

Cruelty concerns

Studies have shown more than 90 percent of the rivers and streams on the Chilean half of the Tierra del Fuego has been redirected by beaver activity, with a massive impact on ecosystems, said Arredondo.

They also contribute to global warming, with downed trees and soil releasing carbon sequestered for centuries or more as the beeches rot.

The socio-economic impact of the rodent invasion was estimated at about US$73 million (S$97 million) in a recent University of Chile study.

Mr Cristobal Arredondo, investigator of the Wildlife Conservation Society shows the effects of beavers on a tree in Tierra de Fuego, Chile, on March 10, 2021. PHOTO: