Group B – Melbourne’s peri-urban grasslands

Temperate native grasslands form one of the most endangered ecosystems in Victoria, with less than 0.5% of their pre-European extent remaining.  Historically, vast areas of grasslands, including most of the Victorian volcanic plain, have been destroyed or substantially altered by agricultural practices such as grazing and cropping.  As a consequence, some of the largest and most intact grassland remnants in Victoria occur on the western and northern fringes of Melbourne, where they are now vulnerable to urban expansion.  Temperate native grasslands around Melbourne support a range of threatened species including the matted flax-lily, spiny rice-flower, button wrinklewort, golden sun moth, growling grass frog, striped legless lizard and grassland earless dragon.

Existing ecological models of this system include:

Temperate native grasslands form one of the most endangered ecosystems in Victoria, with less than 0.5% of their pre-European extent remaining.  Historically, vast areas of grasslands, including most of the Victorian volcanic plain, have been destroyed or substantially altered by agricultural practices such as grazing and cropping.  As a consequence, some of the largest and most intact grassland remnants in Victoria occur on the western and northern fringes of Melbourne, where they are now vulnerable to urban expansion.  Temperate native grasslands around Melbourne support a range of threatened species including the matted flax-lily, spiny rice-flower, button wrinklewort, golden sun moth, growling grass frog, striped legless lizard and grassland earless dragon.

Existing ecological models of this system include:

1. Statistical models demonstrating that the probability a patch of grassland will be degraded or destroyed is much higher if it is on private land, is close to the CBD and/or close to a major road.
2. Models showing that the probability that populations of grassland plants will be extirpated is a function their of life-history characteristics or traits, encroaching urbanisation and changing disturbance regimes.
3. Models of the mean time to extinction for grassland plants showing that small patches of grassland (eg 10-20 ha) are sufficient to support populations for at least 100 years.
4. An algorithm identifying the optimal size of nature reserves to protect multiple species of grassland plants, which shows that many small reserves would be more efficient than fewer, larger reserves. Metapopulation models of the growling grass frog in northern Melbourne, indicating the importance of both habitat quality and connectivity for this species.
5. A variety of modelling tools that integrate conservation planning and land-use planning on the urban fringe.

Questions

Which models of the effects of threatening processes on this ecosystem have been useful for conservation or land-use planning?

Could good decisions about management of grasslands have been made without models?  Is expert judgement enough?

What, if anything, has impeded data collection and the development of useful models?

How can existing data and models be better used to inform land-use planning decisions that affect temperate grasslands on Melbourne’s urban fringe?

What systems/technologies/innovations could be developed to better model the effects of urban expansion and land-use policies on temperate grasslands?

What additional resources or capabilities are required to achieve this?

How could models of this ecosystem be applied more broadly to other ecosystems (eg to other urban landscapes, or to the other three breakout group scenarios)?

Which models of the effects of threatening processes on this ecosystem have been useful for conservation or land-use planning?

Could good decisions about management of grasslands have been made without models?  Is expert judgement enough?

What, if anything, has impeded data collection and the development of useful models?

How can existing data and models be better used to inform land-use planning decisions that affect temperate grasslands on Melbourne’s urban fringe?

What systems/technologies/innovations could be developed to better model the effects of urban expansion and land-use policies on temperate grasslands?

What additional resources or capabilities are required to achieve this?

How could models of this ecosystem be applied more broadly to other ecosystems (eg to other urban landscapes, or to the other three breakout group scenarios)?