Final answer:
A rainforest may not be restored by secondary ecological succession due to loss of original tree species, invasion of non-native species, and human activities.
Step-by-step explanation:
A rainforest can reach a point where it cannot be restored by secondary ecological succession due to various factors. One of these factors is the loss of the original dominant tree species that define the structure and function of the rainforest. When the original tree species are lost, it can be challenging for secondary succession to restore the complex and diverse ecosystem of the rainforest.
Another factor is the invasion of non-native species. Non-native species can outcompete native species and alter the ecological dynamics of the rainforest, making it difficult for secondary succession to occur.
Additionally, human activities such as deforestation and habitat fragmentation can greatly disrupt the natural processes of secondary ecological succession, making it challenging for the rainforest to recover.