As you would no doubt know, the Wheatbelt is in the 14-25 degree...

As you would no doubt know, the Wheatbelt is in the 14-25 degree range when there is soil moisture (winter-spring) and that is when all your carbon would normally be sequestered. I suppose Brazil and Queensland are cooler than WA?

Wind direction seems irrelevant. What wind comes to Australia from Brazil?

If a disease can enter a country from tens of thousands of kilometres away, do you really think a couple of hundred kilometres will act as a barrier to infection?

There are no resistant eucalypt strains anywhere ...