This profile chart is poorly labeled. It shows samples of the amount of time each profiled section of code takes at every tenth of a second of the life of the program. You can see that about 5.7 seconds the camera had just gotten down close enough to the surface to cause a lot of node & mesh creation.

Then from 8.5 seconds till the end of the program as the camera moves along the surface of the planet you can see that the tree is updating rapidly and having to build more meshes.