The introduction of non-native species into new environments is often viewed with alarm, but a growing body of evidence suggests that such introductions can be beneficial. Three main arguments support this view. First, non-native species can enhance local biodiversity. For example, the introduction of the Himalayan blackberry in the Pacific Northwest of the United States has provided food and shelter for native birds and insects, increasing the overall abundance of wildlife in the region. Second, non-native species can fill ecological niches left vacant by extinct or declining native species. In Hawaii, the introduction of the Japanese white-eye, a small bird, has helped pollinate native plants that were losing their natural pollinators due to habitat loss. Third, non-native species can have economic benefits. The cultivation of non-native crops, such as the kiwi fruit in New Zealand, has created a lucrative export industry, boosting the national economy without displacing native agriculture.
🎧 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 claims that non-native species are beneficial, but these arguments are flawed. First, the so-called enhancement of biodiversity is misleading. While non-native species may increase the number of individuals, they often reduce the number of native species. For instance, the Himalayan blackberry in the Pacific Northwest forms dense thickets that outcompete native plants, leading to a decline in native plant diversity. The birds and insects that feed on blackberry are not necessarily native; they may be generalists that thrive in disturbed habitats, masking the loss of specialized native species. Second, the claim about filling ecological niches is problematic. The Japanese white-eye, introduced to Hawaii, does pollinate some native plants, but it also competes with native birds for food and spreads invasive plant seeds. Moreover, the native pollinators that declined were often more effective, so the white-eye is a poor substitute. Third, the economic argument ignores long-term costs. While kiwi fruit is profitable in New Zealand, its cultivation requires extensive land and water resources, displacing native ecosystems and requiring pesticides that harm local wildlife. In addition, the global market for such crops is volatile, and the economic gains may not outweigh the environmental damages.
📝 Writing Prompt 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).
