The concept of rewilding—restoring ecosystems to their pre-human state by reintroducing apex predators and keystone species—has gained traction as a conservation strategy. Proponents argue that rewilding can restore ecological balance, enhance biodiversity, and mitigate climate change. First, reintroducing apex predators, such as wolves in Yellowstone, controls herbivore populations, preventing overgrazing and allowing vegetation to recover, which in turn supports a wider array of species. Second, rewilding promotes biodiversity by creating a mosaic of habitats through natural processes like beaver dam construction, which increases aquatic and riparian species richness. Third, rewilded landscapes can sequester more carbon dioxide, as restored grasslands and forests act as carbon sinks, thus helping to offset anthropogenic emissions. These benefits suggest that rewilding is a practical and cost-effective tool for modern conservation, especially in areas where human intervention has degraded ecosystems. However, critics question its feasibility, but supporters believe that with careful planning, rewilding can be implemented on a large scale.
🎧 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 lecture challenges the claims made in the reading about rewilding's benefits. First, while the reading cites Yellowstone wolves controlling herbivore populations, the lecturer points out that such effects are not universally observed. In many rewilding projects, predators fail to establish stable populations due to human-wildlife conflict, fragmented habitats, or insufficient prey. Even when they do, the trophic cascade is often weaker than expected, as seen in European projects where deer populations remained high, leading to continued forest damage. Second, the lecture argues that rewilding does not necessarily increase biodiversity. In fact, reintroducing keystone species like beavers can alter habitats in ways that harm existing threatened species. For example, beaver dams can flood areas, destroying the nesting sites of ground-nesting birds and reducing plant diversity in wetlands. Thus, the net effect on biodiversity may be negative, contrary to the reading's assertion. Third, the lecture disputes the carbon sequestration claim. Rewilding often involves large herbivores that emit methane and disturb soils, releasing stored carbon. Moreover, grassland restoration may sequester less carbon than mature forests, which are often cleared during rewilding projects. A study from the Scottish Highlands found that rewilding led to a net carbon loss over 30 years due to soil disturbance and reduced tree cover. Therefore, the lecture concludes that rewilding's purported benefits are overstated and may not justify its high costs and ecological risks.
📝 Инструкция по письму 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).
