Is a nikon d3100 good for nature photography?

I would love this camera for nature would i have to get a separate lens cause i'm aware of a manual focus on this camera what do you lot think

I'm sure its great depending on the lens you use

I think its a convex mirror you use.

The 1.5x crop factor may be an advantage in nature photography if you can compose fairly accurately.

Just about any DSLR is great for nature photography with the lenses though you have an option between auto or manual focus, in other words both settings are built into the lens

It's not the camera, it's the person behind it. You can use any camera. Just, experiment with angles and look for natural light. Work with your own imagination, and it doesn't matter what camera you have.