Destroyers of wood

I think that these mushrooms are Hypholoma fasciculare, the sulphur tuft. The only trouble is that they were growing on the rough grass on our local golf course which was laid out on sand dunes. Not the ideal habitat for a species that makes its living by breaking down dead wood! Perhaps there is an old tree root sitting under the sand, or even an old pirate's treasure chest! Or, heaven forbid, perhaps  I have misidentified them?