Wow, they like to make it difficult, don't they?
I'm really not sure of any examples that could be used for all three, sorry. I just tried flicking through the chapter in my uni biology textbook (which is absolutely massive
) on Australia's changing environment, but I couldn't really find anything that would be able to answer your question - it has different examples for each 'heading' or change in Australia's environment too.
I would suggest, as just a rough guide, looking at animals/plants adapted to 'desert' or arid conditions, as I'm thinking they would be more likely to have had to evolve to cope with physical and chemical changes as well as competition (by introduced species).
From my textbook, some extra things to consider that may or may not be helpful:
Physical changes in Australian environment - lots of land clearing and 'habitat fragmentation' has occured since European settlement.
Chemical changes - increasing soil acidification and salinity; atmospheric pollution.
Sorry I can't really help any more (maybe someone else can?)...good luck with it!