the concepts of endemism and biodiversity hotspots, why endemic species and hotspots are especially vulnerable, and their significance for setting conservation priorities

What this dot point is asking

VCAA wants you to define endemism and biodiversity hotspots, explain why endemic species and hotspots are especially vulnerable, and explain how this guides where conservation effort is directed. The course also asks you to apply these ideas to one threatened endemic species, so a clear grasp of endemism is essential.

What endemism means

A species is endemic to an area when it occurs naturally there and nowhere else on Earth. Endemism can be at different scales: a species might be endemic to a continent, an island, a single mountain range, or even one cave or spring. The smaller the range, the more vulnerable the species.

Australia has very high endemism because it has been an isolated continent for tens of millions of years, allowing species to evolve in isolation. Around 85 per cent of Australia's flowering plants, most of its mammals (including all marsupials such as the koala and the platypus's relatives), and most of its frogs and reptiles are found nowhere else. The Wollemi pine (Wollemia nobilis), known from a tiny wild population in a single canyon system, is a striking example of an extremely restricted endemic.

Why endemic species are especially vulnerable

Endemic species, particularly those with small ranges, face heightened risk for several reasons:

• No safety net. A widespread species can survive a local disaster because populations elsewhere persist. An endemic species has no such backup.
• Small population size. Restricted ranges often mean small populations with low genetic diversity, reducing their ability to adapt to disease, drought or new predators.
• Habitat specialisation. Many endemics are adapted to very specific conditions, so habitat loss, fragmentation or climate change can wipe out their entire range.
• Vulnerability to invasive species. Island and isolated endemics often evolved without certain predators or competitors, so introduced foxes, cats or cane toads can be devastating.

The mountain pygmy-possum (Burramys parvus), endemic to a small area of the Australian Alps, illustrates this: it depends on alpine boulder fields and a single key food source, and warming climate plus reduced snow cover threaten its entire restricted range at once.

Biodiversity hotspots

A biodiversity hotspot is a region that meets two criteria: it contains an exceptionally high number of endemic species (a large concentration of species found nowhere else), and it is under serious threat, having lost a large proportion of its original habitat. The concept was developed by conservation biologist Norman Myers to direct limited resources where they protect the most unique biodiversity.

Australia contains internationally recognised hotspots, including Southwest Australia (the wheatbelt and Kwongan heathlands of Western Australia, extraordinarily rich in endemic plants) and the Forests of Eastern Australia. Within Australia, the federal government has also identified national biodiversity hotspots to guide funding.

Significance for conservation priorities

Because conservation funding and effort are limited, hotspots and endemic-rich areas offer the greatest return: protecting a small hotspot area can safeguard a large share of the planet's unique species. This prioritisation underpins decisions about where to create national parks, Indigenous Protected Areas and reserves, and where to focus threat control such as fox baiting or weed removal. It also links to the sustainability principle of conserving biodiversity and ecological integrity, ensuring irreplaceable species are not lost.

Protecting endemics in situ (within their habitat) is preferred because it conserves the whole ecosystem, but for the most threatened endemics, ex-situ insurance populations (captive breeding, seed banks) provide a backup, as with Zoos Victoria's work on the mountain pygmy-possum and orange-bellied parrot.