Understory (under jarrah and marri) crop?

Hi, we've been contemplating clearing a large parcel of naitive bushland (jarrah marri grass trees etc) to plant a fruit tree crop with ground cover crop as well. However clearing all this land is not really what we want to be doing.
Is there another way?
Does anyone know of decent earning crops that we could under plant with minimuml understory clearing?
Cheers