Commonwealth of Australia

Inclusion of ecological communities in the list of threatened ecological communities under section 181 of the Environment Protection and Biodiversity Conservation Act 1999

I, PETER ROBERT GARRETT, Minister for the Environment, Heritage and the Arts, pursuant to section 184(1)(a) of the Environment Protection and Biodiversity Conservation Act 1999, hereby amend the list referred to in section 181 of that Act by:

including in the list in the critically endangered category

Natural Temperate Grassland of the Victorian Volcanic Plain

as described in the Schedule to this instrument.

Dated this….............29th........................day of…...............May............................2008

Peter Robert Garrett

Minister for the Environment, Heritage and the Arts

SCHEDULE

Natural Temperate Grassland of the Victorian Volcanic Plain

The Natural Temperate Grassland of the Victorian Volcanic Plain is an ecological community that is restricted to western Victoria. The ecological community occurs on a large, Quaternary basaltic plain with scattered volcanic cones and stony rises. The soils of the plain are heavy grey to red cracking clays, with black cracking clays common in the low-lying areas. It occurs primarily within the Victorian Volcanic Plain IBRA Bioregion with some occurrences extending into the adjacent Victorian Midlands and South East Coastal Plain IBRA bioregions.

The Natural Temperate Grassland of the Victorian Volcanic Plain is a type of lowland natural temperate grassland. The vegetation is mostly limited to a ground layer of grasses and herbs. Large shrubs and trees are absent to sparse. The ground layer is dominated by native tussock-forming perennial grasses with a variety of herbs occupying the spaces among grass tussocks. The main grass species present are Kangaroo-grass (Themeda triandra), Wallaby-grasses (Austrodanthonia spp.), Spear-grasses (Austrostipa spp.) and Tussock-grasses (Poa spp.). Low gradient ephemeral and intermittent drainage lines may be dominated by a dense sward of the River Tussock-grass (Poa labillardierei). Many of the herbs present are from the daisy, lily, pea and orchid families.

The key defining attributes for the Natural Temperate Grassland of the Victorian Volcanic Plain are:

• It is mainly associated with Quaternary basalt soils within the Victorian Volcanic Plain IBRA bioregion. Pockets of similar grassland extend into the adjacent Victorian Midlands and South East Coastal Plain bioregions. These are included in the ecological community if they meet the other defining and condition thresholds.
• At least one of the following grass genera is the dominant native species in the ground layer: Themeda (Kangaroo-grass), Austrodanthonia (Wallaby-grass), Austrostipa (Spear-grass) and/or Poa (Tussock-grass).

• The minimum size of the grassland patch and the maximum cover of woody vegetation depends on the native vegetation remnant within which the grassland patch occurs. The small minimum size takes into account the fragmented nature of remnants, that small grassland patches can remain effective for conservation purposes, and that grassy woodlands may include naturally open gaps amongst trees.
  • For a native vegetation remnant hectare in size, the minimum contiguous size of the grassland patch is 0.05 hectare and the crown cover of shrubs and trees over one metre tall within the grassland patch should not exceed 5%;
  • For a native vegetation remnant  hectare in size, the minimum contiguous size of a grassland patch is 0.5 hectare and the density of mature trees within the grassland patch should not exceed 2 trees per hectare.

All patches of the Natural Temperate Grassland of the Victorian Volcanic Plain now show a degree of disturbance and degradation. The listed ecological community comprises the patches of better quality that show the key attributes, above, and meet the condition thresholds, below.

• The total perennial tussock cover represented by the native grass genera Themeda, Austrodanthonia, Austrostipa or Poa is at least 50%; OR
• If the total perennial tussock cover represented by the above 4 native grass genera is less than 50%, then the ground cover of native forbs (wildflowers) is at least 50% of total vegetation cover during spring-summer (September to February); OR
• The cover of non-grass weeds is less than 30% of total vegetation cover at any time of the year.

Patches that do not meet the attributes and thresholds above are considered degraded and are no longer included in the listed ecological community.

A patch of the Natural Temperate Grassland of the Victorian Volcanic Plain ecological community is considered to have enhanced conservation value if it shows one or more of the following features:

         a high native plant species richness;

         large patch size;

         minimal weed invasion;

         presence of listed threatened plant and/or animal species;

         presence of natural exposed rock platforms and outcrops; or

         well-developed soil crust (of mosses or lichens) on the soil surface.