Detail Recognition in Ecosystem Lecture
Listen closely to the following passage:
In today's lecture titled 'The Role of Fauna in Ecosystem Stability', Professor Sanchez emphasized that biodiversity is essential for maintaining ecosystem resilience. He noted that certain species, when in abundant numbers, stabilize food webs and contribute to nutrient cycling. Furthermore, he discussed how keystone species, such as wolves and sea otters, help regulate populations of other species, preventing overgrazing or overpopulation. For instance, the decline of sea otters in the North Pacific led to an explosion of sea urchin populations, which devastated kelp forests. In contrast, the conservation of wolves in Yellowstone National Park has led to a healthier ecosystem by controlling elk populations which, in turn, supports various plant species. The professor concluded by highlighting the importance of protecting these animals to ensure ecological balance.
Note: This question has been adapted from its original format to accommodate a reading-based version. In the official TOEFL exam, speaking and listening sections require verbal responses and audio prompts, which are not represented here. Please note that this adaptation may not fully reflect the nature or difficulty of the official exam. The audio feature for these sections will be available soon.