Seems like not only plants and animals can be invasive. Yesterday, while walking along Forest Track, I spotted an unusual Fungi fruiting on a fallen log. It was a vivid orange colour and seemed to have an unusual pore arrangement on the underside. After snapping a few photos, I headed home to consult the field guides. Seeing nothing really to match, I uploaded the photo to http://www.Bowerbird.org.au where a subscriber there quickly identified it as an exotic species, Favolaschia calocera otherwise known as Orange Pore Fungi.
This Fungi apparently is a recent arrival to Australia the first record of it is from 2005. It was first observed in Madagascar and has recently spread to a number of countries across the globe. According to Wikipedia it colonises ruderal sites (Wastelands/Roadsides) where it can become the dominate species. Fingers crossed it does not become a dominate feature of our not so ruderal forests. Not sure how you can weed out or control a pest fungi.