General:
* What is the most important thing humans can do to protect nature?
* How does climate change affect different ecosystems?
* What are the ethical implications of human interaction with nature?
* How does nature inspire art, music, and literature?
Specific to Animals:
* How do animals communicate with each other?
* How do different species adapt to their environments?
* What is the impact of invasive species on native wildlife?
* How do animals navigate and find their way around?
Specific to Plants:
* What are the different ways plants reproduce?
* How do plants defend themselves from predators?
* How do plants contribute to the air we breathe?
* What are the benefits of growing native plants?
Specific to Ecosystems:
* How do different ecosystems interact with each other?
* What is the role of biodiversity in a healthy ecosystem?
* What are the consequences of deforestation and habitat loss?
* How can we restore degraded ecosystems?
Other:
* What are the unique challenges facing nature in urban areas?
* How can technology be used to help protect and understand nature?
* What are the benefits of spending time in nature for human health?
* How can we promote a more sustainable relationship with the natural world?
For younger audiences:
* What makes a tree grow tall?
* How do birds build their nests?
* Why are bees important for flowers?
* Where do butterflies go in the winter?
This list is just a starting point! There are endless questions to ask about the natural world. Remember to tailor your questions to your specific interests and the audience you are addressing.