Sleeping giants Because the lag phase can be decades, it's considered likely that in Australia we have many species that are waiting before they break out into a problem. These 'sleeping giants' will be expensive to control in the future, unless we take action now. Identifying a likely troublemaker before it hits its exponential growth is not always easy. People appreciate the flowers and therefore the species is not considered a weed. This is an example of how perceptions can affect our priorities.
Biodiversity is about local uniqueness.
We can't hope to eradicate or even control all the invasive species that we have in Australia. Unfortunately, Richard said he did not have an answer. However, he did offer an example from South Africa, which he had recently been visiting. There are huge weed problems in that country - ironically, many are caused by Australian species. The introduced pines, hakeas and acacias use more water than many of the native species.