Thanks fu,
I am not worried about the slight chance losing shrubs and small stuff its just the three 60 year old trees that i have been mulching i would prefer not to risk. They are stuffed from the drought and huge huge bills if they snuff it, they are big trees. I have a few local prof arborist i can order from, i currently use the milled pine bark from sustainable plantations which is excellent it just looks to flat and one coloured and prefer the natural look/nutrition the fresh stuff has. The treatment sounds like a bit of a pain, best to make sure the mulch is clean. The botanist on gardening aust was saying the nasty fungal diseases are popping up because a lot of trees are under drought stress and easy targets. Thats what alarmed me, lots of dead/sick trees, lots of work for loppers, lots of crap mulch....