The concept of 'rewilding'—restoring ecosystems by reintroducing large carnivores and other keystone species—has gained popularity as a conservation strategy. Proponents argue that rewilding can restore ecological balance, enhance biodiversity, and mitigate climate change. First, reintroducing apex predators like wolves can control herbivore populations, preventing overgrazing and allowing vegetation to recover. For example, in Yellowstone National Park, wolf reintroduction led to a cascade of effects that regenerated willow and aspen trees. Second, rewilding can increase biodiversity by creating habitats for various species. Large herbivores such as bison and elk disturb soil and vegetation, promoting plant diversity and providing niches for insects and birds. Third, rewilding can sequester carbon. Grazing and predation dynamics can enhance soil carbon storage, as healthier grasslands and forests absorb more CO2. Thus, rewilding offers a nature-based solution to environmental degradation and climate change.
🎧 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 reading's optimistic view of rewilding. First, the Yellowstone example is misleading. While wolves did reduce elk numbers, the recovery of vegetation was also influenced by other factors, such as drought and human management. In many other regions, reintroducing predators has not produced similar trophic cascades because ecosystems are too fragmented or lack sufficient prey. Second, the claim that rewilding increases biodiversity is oversimplified. Reintroducing large herbivores can actually harm certain species. For instance, bison can trample rare plants and compact soil, reducing diversity in sensitive habitats. Moreover, in areas where humans live, rewilding can lead to conflicts, as predators attack livestock, undermining local support for conservation. Third, the carbon sequestration argument is weak. Studies show that the net carbon effect of rewilding is uncertain and often negligible. In some cases, increased methane emissions from wild herbivores can offset any carbon gains. Therefore, while rewilding has potential, it is not a straightforward solution and may have unintended negative consequences.
📝 写作提示 Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
