Scientific review of the impact of land clearing on threatened species in Queensland

https://www.ehp.qld.gov.au/wildlife/threatened-species/documents/land-clearing-impacts-threatened-species.pdf

This Report from the Species Technical Committee was released by Minister Steven Miles, Minister for Environment and Heritage and Minister for National Parks on 21st July 2017

Executive summary

• Internationally and nationally, habitat loss is the greatest threat to threatened species.
• More than 400 ecologists, including leading conservation scientists from Australia and around the world, have issued a declaration in 2016 warning of the devastating impacts of land clearing on Australia’s biodiversity.
• Numerous scientific, peer reviewed studies have been published warning of the impacts of land clearing on biodiversity and threatened species.
• The woody vegetation clearing rate in Queensland increased in the period 2013-2015 to 296,000 hectares per year, and was 3.8 times the rate of woody vegetation clearing in 2009-10.
• The Brigalow Belt, Central Queensland Coast, New England Tableland, Southeast Queensland and Wet Tropics bioregions are fragmented landscapes resulting from historical and recent land clearing. The Mulga Lands and Desert Uplands bioregions have been increasingly fragmented in recent years.
• Land clearing causes species death and habitat loss, but also exacerbates other threatening processes, particularly in fragmented landscapes.
• Land clearing reduces the resilience of threatened species populations to survive future perturbations such as climate change.
• Apart from the immediate impacts of clearing, significant time lags occur before the full cumulative impact on biodiversity is realised.
• The impact of the previous century of land clearing has resulted in small, fragmented relictual populations of many native species. Any further land clearing will further elevate the extinction pressure arising from loss of habitat and a range of other threatening processes which are exacerbated by fragmentation.
• Land clearing has significant negative impacts offsite e.g. (sediment runoff into streams, rivers, wetlands and the Great Barrier Reef marine lagoon), and is a major contributor to climate change through greenhouse gas outputs, and rainfall and temperature dynamics.
• Land clearing has been directly responsible for two plant species becoming extinct in the wild, and has been identified as a threatening process for many of the 739 threatened flora species and 210 threatened fauna species in Queensland.
• Eight species are discussed in a series of case studies indicating the major reduction in the area and quality of habitat that historic and recent land clearing has caused.
• The current State protected area estate and voluntary nature refuge estate combined only retain 11.4% of the pre-clearing potential habitat for terrestrial threatened species, and hence are unlikely to prevent further species from becoming extinct.