1. How are keystone species linked to species richness? Provide an example of a keystone species.
2. Provide a specific example of how a trophic level in a food chain might occasionally interact with another food chain and in doing so, become part of a larger food web. You may make up an example if you wish.
3. Some countries are becoming more affluent: China and India, for example. Describe two ways in which greater, more widespread affluence is likely to affect the global ecosystem.