Loss of habitat

Loss of habitat is one of the most serious threats to Australia’s terrestrial biodiversity. According to a statement released at the Society for Conservation Biology Oceania conference in Brisbane in 2016, land clearance in recent years has tripled, mainly to facilitate the expansion of pasture, agriculture and urbanisation. Woodland and forest loss is at nearly 300,000 hectares per year (according to the government’s latest figures) putting Australia amongst the world’s worst deforestation countries in the developed world1.

Historically vegetation clearance has been extensive in the Mount Lofty Ranges with only 13% of the original native vegetation remaining. In the Adelaide Hills Council region, remaining native vegetation cover is estimated at approximately 17,265 hectares, which is 21.7% of the total council area. These statistics reflects total ‘vegetation coverage’ and is misleading because it does not consider the condition of the vegetation community, so the actual area of viable habitat could be much lower.

As native vegetation continues to be cleared from the landscape or is further compromised by weed invasion and other destructive impacts, the lack of cover and subsequent loss of habitat begins to disadvantage local native species. It is considered that regional habitat retention targets must be at least 30% remnancy to avoid substantial loss of regional wildlife species, in particular birds2 and catastrophic loss of species can be expected when vegetation cover drops below 10%3.

It is vital to the region’s wildlife that ongoing land management focuses on retention and restoration of remaining native vegetation, as well as re-establishment of wildlife habitat through revegetation with local provenance species. Creation of wildlife corridors, or ‘biodiversity corridors’, is also necessary to improve connectivity of fragmented patches and better enable the movement of wildlife across the landscape.

Of the 17,265 hectares of native vegetation remaining, it is estimated that 31.5%, or 5,447 hectares is protected or managed for conservation in either the National Parks and Wildlife Reserves System, Heritage Agreements, Bush for Life sites and some Council parks and reserves.

1Society for Conservation Biology/UNSW (2016)

2Possingham, H. P. and Field, S. A., (2001). Regional bird extinctions and their implications for vegetation clearing policy. Lifeline 7:15–16.

3DEH (2009) Informing Biodiversity Conservation for the Adelaide and Mount Lofty Ranges Region, South Australia. Priorities, Strategies and Targets.