In paragraph 9, "prone" is used to indicate that the forests are susceptible or inclined to superhot fires. This is inferred from the context, stating that the forests are overcrowded and the fires can kill older trees, sterilize the soil, and pose danger to firefighters. The term suggests a vulnerability to specific adverse conditions. rewrite like a 9th grader

In paragraph 9, the word "prone" means that the forests are more likely to have superhot fires. This is because the forests are overcrowded, which makes it easier for fires to spread and destroy older trees. These fires can also harm the soil and put firefighters in danger. "Prone" shows that the forests are vulnerable and not well-equipped to handle these dangerous conditions.