Loss of native vegetation

Clearing of native vegetation (historical, present and future) remains one of the major threats to terrestrial biodiversity in the south west. It contributes to the the physical loss of flora, fauna and their habitat; and reduces the resilience of the remaining vegetation and biodiversity to pressures such as weed invasion, vegetation fragmentation, fire, feral animals and climate change.

While just over half (53%) the vegetation has been cleared across the whole SWCC region, some areas have been cleared more extensively. Most notably, on the Swan Coastal Plain (80% lost), Avon Wheatbelt and Mallee IBRA regions (84.7% and 89.4% lost respectively)1(Ecotones, 2018).

More than half of native vegetation cleared since European settlement

Clearing of native vegetation presents a significant challenge for land manages as reversing the impacts is costly and difficult.

Native vegetation clearance varies significantly across the SWCC region and this is closely aligned with different landuses ie: housing, industry and agriculture.  Loss of native vegetation is most notable on the Swan Coastal Plain (80% lost) and in the Avon Wheatbelt and Mallee IBRA Regions (84.7% and 89.4% lost respectively)1, (Ecotones, 2018). The Jarrah Forest IBRA region includes roughly equal forest and farming/other land use (46.7% vegetation lost), while the Warren region is largely intact at present (only 19.3% cleared)1, (Ecotones, 2018).

Clearing regulation and geographical recording of clearing permit data began in 2004 by the Department of Water and Environmental Regulation (DWER), however no single database captures all clearing (exempt and permitted) that occurs in WA (Environmental Protection Authority, 2017).  Since 2004 10,582ha have been approved for clearing by DWER; however, this does not include exempt or illegal clearing (nor indicate if the clearing has occurred or not)2.

Calls to action:

  • Prevent further loss of native vegetation where possible.
  • Fence off remnant native vegetation from stock grazing.
  • Protect existing vegetation from ongoing threats such as invasive weeds and animals, grazing, Phytophthora Dieback, inappropriate fire regimes, illegal 4-wheel driving and rubbish dumping.
  • Undertake revegetation to supplement the loss of native vegetation.

Data Source:

  • Department of Primary Industries and Regional Development Native Vegetation Extent data (updated August 2017). Available at: www.data.gov.au [accessed March 2018].
  • Department of Water and Environmental Regulation (DWER) Native Vegetation Clearing Permit Data (accessed March 2018). Data analysis by DWER.

Disclaimer: The Department of Department of Primary Industries and Regional Development maintains remnant vegetation mapping, which is used by a number of agencies for conservation policy and planning; and was also used for this analysis. However, there are significant differences between areas of the State in terms of the age and resolution of the mapping and therefore accuracy varies in currency.

References

Ecotones (2018). Environmental Snapshot GIS & Data Analysis. Report for South West Catchments Council.     

Environmental Protection Authority. (2017) Environmental Protection Authority Annual Report. [online] Available at: http://www.epa.wa.gov.au/sites/default/files/Annual_reports/EPA%20Annual%20Report%202016-2017.pdf