Hi,
The way you have things set up you have the terrain nodes and Base colours shader node feeding into the Lake node via the Distribution-Base shader. This is essentially causing all of your terrain to be displayed in the area covered by the lake and not outside it. Instead of displacing the planet surface with your terrain nodes you're only displacing the lake, for example.
I think what you want to try is connecting the Base colours node back to the Surface shader input of Planet 01. You probably also want to disconnect the Base colours node from the Distribution-Base node. Now you will have the terrain etc. effecting the planet again and your lava nodes only effecting the lake surface.
I'm not sure if you're aware of this, but your lake is huge, about 200km across. There is not much of the terrain sticking through it. Before I realised how big your lake is it was confusing me because I was only seeing lake and no terrain. When I zoomed out so I could see the extents of the lake things started to make more sense.
Look at the connections in the network view like a series of pipes. In your file all the pipes from the terrain nodes are running into the Lake node via the Distribution-Base node. You can see that there aren't any pipes to take values out of the Lake node, so that suggests it's all stopping in the Lake node. Is that what you want to do, have the terrain values go through the pipes into the lake? Probably not. Instead you should have the pipes with the values you want in the Lake node flowing into the lake and the pipes with the terrain values flowing into the planet.
Regards,
Jo
