In 1946 Argentina had a plan to grow a local fur trade and in 1946 decided to introduce 25 pairs of beavers from Canada into their wildlife. Little did they know the devastating effect these beavers would have on the local wildlife. The large rodents have been running completely wild without any natural predator for years.
Those 50 initial beavers quickly multiplied and now as last checked in 2015, Argentina is estimated to contain around over 200,000 local beavers in their forests. Their population continues to explode and in regions like Tierra del Fuego, they have become an overgrowing problem. Small trees are cut down within a couple of hours, and massive trees that have decorated the landscape for 100s of years are chopped down in a couple of days. And the worst part of the problem is these trees will never grow back because the beavers just keep coming.
The riverbanks are of course were the worst of the problem stems, beavers love to build their homes in dams and this causes the water to overflow: flooding the whole area. It is believed the beavers are the culprits for destroying an area around the size of Buenos Aires, as you can imagine locals have now had enough. What happens is the flooding downstream causes land to become completely uninhabitable due to destroying the soil quality.
Therefore the beavers are disrupting the whole ecosystem of Argentina, the flooded soil becomes acidic and causes vegetation to die. Meaning the main economic resource of Argentina like raising horses, goats and cattle are impossible. In fact, the land becomes so flooded they cannot even build on it.
Argentina looked on to its neighbor Chile for support, and in 2015 implemented a beaver culling program which is thought will take 10 to 15 years to really rectify the problem. Due to the beavers not having any local predators, the program has the support from environmental groups. Another proof that when it comes to mother nature, we should just let Earth decide and not move wildlife around.