托福mock test 1听力环境科学 Lecture 2 原文解析+音频翻译

[00:00.00][00:00.27] Listen to a talk in an environmental science class.
[00:01.00][00:05.48]Man: Restoring ecosystems to a more natural state has become a powerful conservation strategy. Known as rewilding, this approach often involves reintroducing species that once thrived in an area, removing human-made barriers, and allowing natural processes to resume.
[00:02.00][00:23.56] A well-known example is the return of wolves to Yellowstone National Park in the United States. Their reintroduction in 1995 helped reduce an overabundant elk population, which had been overgrazing young trees and shrubs, especially in river valleys.
[00:03.00][00:41.05] With fewer elk, vegetation like willows and aspens recovered, improving habitats for species such as beavers and birds. This chain reaction, known as a trophic cascade, shows how a single predator can reshape an entire ecosystem.
[00:04.00][00:57.84] Now, despite its promise, rewilding faces challenges. Local communities often worry about the risks that large predators—such as wolves—pose to livestock, pets, and human safety. Policymakers have responded with measures such as compensation programs for livestock losses.
[00:05.00][01:17.52] Ecologically, rewilding is complex and often unpredictable. Long-term monitoring is crucial to understand how species adapt, how ecosystems evolve, and whether biodiversity is improving.
[00:06.00][01:31.07] Tools like GPS tracking and satellite imagery help scientists observe animal movements, assess ecosystem health, and detect early signs of disruption.