7. Threats Identifying actual and likely threats to ecological character serves an important function in framing future management planning and action. They may also provide initial guidance in assessing likely impacts of potential development proposals under the EPBC Act (DEWHA 2008a). This chapter is not a comprehensive threat assessment. Rather, only those factors that pose a significant threat to the critical components, processes, benefits, and services, are discussed. Table 7.1 Summary of key threats to the ecological character of LLNR Ramsar site Threat Potential impacts Likelihood of Timing occurrence Weeds Introduced pasture grasses out-compete: Themeda grassland reducing habitat quality for nationally Medium High* Short term – threatened Austral toadflax. Components of the nationally endangered peppermint grassy Medium High* Short term – woodland community Other weeds displace native terrestrial and wetland flora Medium High* Short term – Feral European red fox and feral cat predate fauna including waterbirds, Medium High* Short term – frogs, reptiles, and invertebrates, possibly reducing populations of animals these species. Grazing and soil disturbance by rabbits can displace the sensitive Medium High* Short term – herb Austral toadflax which is nationally endangered. Gambusia holbrookii can displace native fish and frog species High* Short term through aggression and predation. Soil Disturbance by vehicles can: Damage individuals of the sensitive herb Austral toadflax Medium Short term disturbance which is nationally endangered. and erosion Reduce water quality and disturb vegetation in watercourses Medium High Immediate – and wetlands. Hydrological Groundwater change as a result of groundwater extraction or Low Medium to exploration or extraction of minerals and other resources. long term interference Disturbance of outflow level of both lakes Low Medium to long term Modification to surface flows Medium Medium to long term Ongoing catchment erosion and lake bed sedimentation above High Long term background levels is likely to accelerate the reduction in water depth that would occur naturally. Climate Average temperature will rise High (virtually Medium certain) term change Rainfall will increase in all seasons except winter Medium (likely) Medium term Structure, composition, and function of ecosystems will change Medium (likely) Medium term Drier soil conditions will occur in spring and winter Medium (likely) Medium term *depending on success of management programs Note: immediate = occurring now, short term = 0-25 years, medium term = 25-50 years, long term = >50 years.
7. Threats Identifying actual and likely threats to ecological character serves an important function in framing future management planning and action. They may also provide initial guidance in assessing likely impacts of potential development proposals under the EPBC Act (DEWHA 2008a). This chapter is not a comprehensive threat assessment. Rather, only those factors that pose a significant threat to the critical components, processes, benefits, and services, are discussed. Table 7.1 Summary of key threats to the ecological character of LLNR Ramsar site Threat Potential impacts Likelihood of occurrence Timing Weeds Introduced pasture grasses out-compete: Themeda grassland reducing habitat quality for nationally threatened Austral toadflax. Components of the nationally endangered peppermint grassy woodland community Other weeds displace native terrestrial and wetland flora Medium – High* Medium – High* Medium – High* Short term Short term Short term Feral animals European red fox and feral cat predate fauna including waterbirds, frogs, reptiles, and invertebrates, possibly reducing populations of these species. Grazing and soil disturbance by rabbits can displace the sensitive herb Austral toadflax which is nationally endangered. Gambusia holbrookii can displace native fish and frog species through aggression and predation. Medium – High* Medium – High* High* Short term Short term Short term Soil disturbance and erosion Disturbance by vehicles can: Damage individuals of the sensitive herb Austral toadflax which is nationally endangered. Reduce water quality and disturb vegetation in watercourses and wetlands. Medium Medium – High Short term Immediate Hydrological interference Groundwater change as a result of groundwater extraction or exploration or extraction of minerals and other resources. Disturbance of outflow level of both lakes Modification to surface flows Ongoing catchment erosion and lake bed sedimentation above background levels is likely to accelerate the reduction in water depth that would occur naturally. Low Low Medium High Medium to long term Medium to long term Medium to long term Long term Climate change Average temperature will rise Rainfall will increase in all seasons except winter Structure, composition, and function of ecosystems will change Drier soil conditions will occur in spring and winter High (virtually certain) Medium (likely) Medium (likely) Medium (likely) Medium term Medium term Medium term Medium term *depending on success of management programs Note: immediate = occurring now, short term = 0-25 years, medium term = 25-50 years, long term = >50 years.
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