The concept of 'rewilding'—restoring ecosystems to their pre-human state by reintroducing large herbivores and predators—has gained popularity as a conservation strategy. Proponents argue that rewilding can restore ecological balance, enhance biodiversity, and mitigate climate change. First, reintroducing keystone species like wolves can control overpopulated herbivores, allowing vegetation to recover and creating a trophic cascade that benefits many species. For example, in Yellowstone National Park, wolf reintroduction reduced elk populations, leading to regrowth of willows and aspens, which in turn supported beavers and songbirds. Second, rewilding large tracts of land can create carbon sinks; grazers and their predators promote soil health and grass growth, which sequester significant amounts of carbon dioxide. Studies in the Serengeti suggest that restoring wildebeest populations increased carbon storage in soils by up to 30%. Third, rewilding can be economically beneficial through ecotourism, as seen in Scotland where proposals for lynx reintroduction have sparked interest, potentially generating revenue for rural communities. Thus, rewilding offers a holistic solution to environmental degradation.
🎧 听力讲座
🎯 模拟考试环境：先点「播放讲座」听完内容，再作答。听力原文默认隐藏。
The reading presents a rosy picture of rewilding, but the reality is far more complex. First, the Yellowstone example is misleading. While wolves did reduce elk numbers, they also caused a shift in elk behavior, concentrating their grazing in certain areas, which prevented full vegetation recovery in those zones. Moreover, the so-called trophic cascade is not always consistent; many species, such as ground-nesting birds, actually declined due to increased predation by recovering mesopredators like coyotes. Second, the claim about carbon sequestration in the Serengeti is based on a single study that has not been replicated. Other research shows that large herbivores can compact soils and reduce carbon storage, especially in dry regions. Furthermore, the net carbon effect depends on complex factors like fire regimes, which are often altered by rewilding. Third, the economic argument overlooks the costs. Ecotourism revenue is uncertain and may not offset the losses suffered by local farmers whose livestock may be killed by reintroduced predators. In Scotland, for instance, sheep farmers face significant financial risks, and compensation schemes are often inadequate. Therefore, rewilding is not a panacea but a risky experiment with unintended consequences.
📝 Instrucciones de escritura Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
📊 TOEFL Integrated Writing Rubric
Content Accuracy: Accurately capture the relationship between lecture and reading
Information Completeness: Cover all key counter-arguments from the lecture
Structure & Coherence: Logical organization and progression
Language Use: Grammar, vocabulary, expression accuracy
Scored 0-30 based on holistic scoring (original 0-5, scaled to 30).
