Question 26

Ranch expansion in South America harms the environment mainly by clearing rainforest for pasture.

Clearing rainforest for pasture is a significant environmental concern associated with ranch expansion in South America. This practice leads to habitat destruction, loss of biodiversity, and contributes to climate change through increased carbon emissions.

A) damming valleys for cattle water

Damming valleys for cattle water can impact local ecosystems, but it is not the primary method by which ranch expansion harms the environment. While it can alter water flow and affect aquatic habitats, clearing land for pasture has a far greater impact on deforestation and biodiversity loss.

B) irrigating pasture

Irrigating pasture can lead to issues such as water depletion and soil salinization, but it is not the main way ranch expansion damages the environment. The more pressing concern is the large-scale deforestation that occurs during the establishment of pastureland, overshadowing the effects of irrigation.

C) overgrazing that enriches soil

Overgrazing typically degrades soil rather than enriches it, leading to soil erosion and desertification. While overgrazing is a concern, it is secondary to the immediate and widespread environmental damage caused by clearing rainforests for pasture.

D) clearing rainforest for pasture

Clearing rainforest for pasture is the primary environmental harm caused by ranch expansion in South America. This process leads to significant biodiversity loss, contributes to global warming through deforestation, and disrupts local ecosystems.

Conclusion

The choice of clearing rainforest for pasture is the correct answer as it encapsulates the most severe environmental impact of ranch expansion, directly linking it to habitat loss and climate change. Other options, while relevant, either address less significant impacts or misunderstand the consequences of ranching practices.