We had a big, bad hurricane come through where I live, several months ago.
I've got a whole bunch of big, tall pines and oaks that were blown down.
Still involved cutting those things up.

Where the trees went over, there's big craters, with lots of broken, big
root pieces sticking up. In order to fill the craters and smooth things
over, every one of the roots has to be cut off below the surface before we
put fill dirt in and smooth over.

This is tricky. To get to the roots for a clear cut, you just about always
end up with dirt still close on one side or the other, or the root partially
embedded at the only spot clear to make a cut below ground level. To make
the cut with a chainsaw, it kills the blade rapidly, because, inevitably,
you end up with some area of the chain blade down in the dirt, during some
part of the cut.

Anyone know of any other way of cutting almost buried roots with any degree
of efficiency?

I'm thinking maybe going to a sawzall might be a better answer, as it's
easier to change blades, and I hope they would give me more cuts than the
chain dulling cycles do.

I'm not sure there's any good answer to this problem.