Habitat destruction, degradation and fragmentation
Habitat destruction, degradation and fragmentation have been the major cause of plant extinctions in Australia, and imperil 27% of nationally listed threatened species (to a high or medium degree). The most severe form is land clearing – mainly for agriculture.
Australia is one of the world’s deforestation hotspots. More than 45% of our forests have been cleared since European settlement. Ten million hectares have been cleared since 2000, including 3 million hectares of remnant forests, mostly eucalypt woodlands. Most was in Queensland for beef production. The losses between 2000 and 2017 included more than 7.7 million hectares likely to have been the habitat of threatened species.
Australia has accrued an ‘extinction debt’, due to the time lag (often decades) between habitat degradation and local extinctions. In fragmented woodlands, for example, birds are still progressively being lost even where there has been little clearing in the past century.
Stopping land clearing will require stronger federal, state and territory laws and abating the habitat loss will require ambitious restoration efforts. Priorities include:
- strictly protecting the habitat of threatened species and ecological communities
- strengthening protection of remnant forests and high-value regrowth
- aiming for substantial net forest gain
- promoting restoration in high-priority areas.
“Without clear policies to regenerate degraded forests and protect existing tracts at a massive scale, Australia stands to lose a large proportion of its remaining endemic biodiversity.” – Bradshaw 2012