The mushroom harvester from forestry only works on huge mushrooms, and while those are produced by the mushroom farm, that requires a constant source of mycelium, and the dampeners to make them take up huge amounts of wheat... the other sane option is to use a mushroom terraformer from ic2.
On the other hand nobody seems to have any idea how to reduce the range of a terraformer so that your entire world does not turn into a mushroom island.
On the other hand nobody seems to have any idea how to reduce the range of a terraformer so that your entire world does not turn into a mushroom island.