Final answer:
The possibility of saving the American chestnut tree can be approached with cautious optimism.
Step-by-step explanation:
The possibility of saving the American chestnut tree can be approached with cautious optimism. The Asian chestnut blight greatly reduced the population of American chestnut trees, but efforts are being made to save and restore the species. Specific evidence from the text includes the impact of the blight on the forest ecosystem, the replacement of chestnut trees by oaks, and the extinction of moth species specific to chestnut. These examples highlight the challenges but also the potential for conservation and restoration.