Compiled by James O'Connor and Julie Kirkwood
This report features articles on a small number of Australia’s precious islands, but it is only a snapshot of the situation, as more than 8,300 islands occur within Australia’s jurisdiction. Indeed, only a small number of these islands are ever visited regularly by people who record biological data, and precious little is known about most of them. We are left to make inferences about what is happening on those unknown islands from what is happening on the few we have studied. Nevertheless, some distinct themes emerge from the articles in this report: a high level of endemism means islands represent a critical biodiversity ark; even small increments of climate change-induced sea-level rise will have grave consequences for low-lying islands; and invasive species have already caused widespread devastation of many islands’ biological resources and ecological processes, and continue to do so at an alarming rate. We tend to know much more about islands inhabited by humans, of course, and the processes on inhabited islands are likely to be distinct. Patterns of invasion of islands by novel species, for example, are bound to be heavily influenced by human habitation: by contrast, climate change and sea-level rise will affect any island on the basis of its physical situation. Opportunities for mitigation, too, may depend on whether an island is inhabited. For instance, most examples of successful eradications and reintroductions have, so far, come from uninhabited islands, although there are some notable exceptions.
While we may know little about many of our islands, what we do know is that, by their nature, they constitute a unique and precious biological resource; and that, while they are extremely vulnerable to degradation and extinctions, they also represent unique opportunities for providing real and effective conservation measures for the protection of a large proportion of our natural heritage.