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- Bioregional Assessment Program
- Gippsland Basin bioregion
- 1.1 Context statement for the Gippsland Basin bioregion
- 1.1.7 Ecology
- 1.1.7.2 Terrestrial species and communities
1.1.7.2.1 Principal vegetation types and distribution patterns
The impact of vegetation clearing in the Gippsland Basin bioregion is evident with 57% of the bioregion covered with non-native vegetation and buildings (Table 20). Of native vegetation identified in the NVIS, 12% of the Gippsland Basin bioregion is covered in eucalyptus tall open forest and open forest with ferns, herbs, sedges, rushes or wet tussock grasses predominately in the east (Figure 44). A large area of open forest is situated in the southern Strzelecki Ranges. The combined eucalyptus open forest categories in Table 20 occupy 23% of the Gippsland Basin bioregion. Collectively, Eucalyptus woodlands occupy a smaller area (8%) but show a high association with palustrine and lacustrine wetlands (16%) compared to eucalyptus open forest (9%);Table 20). Acacia, Melaleuca and Banksia forest or shrublands are associated with marine and estuarine wetlands (12%) as are saline or brackish sedgelands or grasslands (5%).
Figure 44 National Vegetation Information System (NVIS) major vegetation subgroups
Data: Department of the Environment and Water Resources (Dataset 2)
1.1.7.2.2 Species and ecological communities of national significance
The EPBC Act lists threatened flora, fauna and ecological communities under a number of classifications. In the Gippsland Basin bioregion the common classifications and their definitions include:
- Critically Endangered: species face a high risk in the wild of extinction in the immediate future
- Endangered: species face a high risk in the wild of extinction in the near future
- Vulnerable: species face a high risk in the wild of extinction in the medium-term future.
Approximately 24 flora species are nationally protected, with six classified as Endangered and 15 as Vulnerable (Table 22).
Within the fauna biodiversity asset group (Table 22), a total of 45 fauna species are listed as threatened including frogs (one Endangered, four Vulnerable), bats (one Vulnerable), fish (two Vulnerable), invertebrates (one Vulnerable), mammals (six Endangered, five Vulnerable), marine birds (two Endangered, six Vulnerable), waders (one Vulnerable), passerine birds (two Endangered), non-passerine birds (one Critically Endangered, three Endangered, two Vulnerable) waders (one Vulnerable) and reptiles (one Endangered, one Vulnerable).
The Orange-bellied Parrot (Neophema chrysogaster), endemic to southern Australia, is the only Critically Endangered species thought to occur in the Gippsland Basin bioregion in association with Jack Smith Lake, indicating potential water dependence.
The importance of the natural diversity maintained within Wilsons Promontory National Park is highlighted with designation of the National Park as a UNESCO biosphere reserve in 1981. Diverse vegetation communities exist which include warm temperate and cool temperate rainforest, tall open forests (Eucalyptus spp.), woodlands, heathlands, swamp and coastal communities including mangroves (Parks Victoria, 2002). Three threatened fauna species and three flora species occur within Wilsons Promontory National Park (species name identified with c in Table 22) and one EPBC Act listed migratory species, Sanderling (Calidris alba).
Threatened ecological communities
Ecological communities consist of a naturally occurring group of animals, plants or other biota that interact in a unique habitat. There are 12 EPBC Act listed threatened ecological communities (not shown) in the East and West Gippsland Catchment Management Authorities, however, only four are likely to occur in the Gippsland Basin bioregion (Table 22). Three communities are Critically Endangered including the ecologically significant Gippsland Red Gum (Eucalyptus tereticornis subsp. mediana) Grassy Woodland and Associated Native Grassland. One community, the Subtropical and Temperate Coastal Saltmarsh, is listed as Vulnerable.
The Gippsland Red Gum Grassy Woodland and Associated Native Grassland community is endemic to the region and nationally important as a temperate grassland and grassy woodland ecosystem. Temperate grassland ecosystems are poorly preserved and conserved nationally, and their decline in Gippsland is largely due to land clearing (DEWHA, 2010). The community provides habitat to other threatened flora and fauna and is known to be rich in wildflowers and other plant species (DEWHA, 2010). The association of this vegetation community with water bodies (Table 20) suggests some level of water dependency.
1.1.7.2.3 Species of regional significance
Victoria’s Flora and Fauna Guarantee Act 1988 (the FFG Act) provides the statutory mechanism for the conservation of flora and fauna that are threatened in the state. In the Gippsland Basin bioregion, 41 flora species are listed as Threatened (FFG Act) of which 16 are listed as Endangered and 11 as Vulnerable (the EPBC Act) (Table 22).
Threatened fauna species total 35 and include four frogs, one bat, two fish, one invertebrate, nine mammals, eight marine birds, two passerine birds, six non-passerine birds, one wader and two reptiles. Many of the FFG Act listed fauna species are also EPBC Act listed (Table 22).
The Victorian Department of Environment, Land, Water and Planning (DELWP) Threatened Species Advisory List is an additional non-statutory state listing of importance to planning processes. Approximately 32 flora species are listed as Endangered and 70 as Vulnerable. There are ten fauna species that are listed as Critically Endangered, 15 are listed as Endangered and 12 listed as Vulnerable.
Threatened ecological communities
State ecological vegetation community mapping (Native Vegetation-Modelled 2005 Ecological Vegetation Classes (EVC)) identifies 629,569 ha of vegetation communities in the Gippsland Basin bioregion of which 139,906 ha (22%) have a Victorian Bioregional Conservation Status of Vulnerable and 100,775 ha (16%) are Endangered (Figure 45). Broad EVC groups that are Endangered include riparian scrubs or swamp scrubs and woodlands (31,000 ha), plains woodlands and forest (including grasslands, 25,000 ha) and damp forests (24,000 ha). Many other Endangered EVC groups exist within the bioregion, but cover much smaller areas. Lowland forest (51,000 ha), plains woodlands and forest (including grasslands, 30,000 ha) are considered Vulnerable. Approximately 12,000 ha of wetland species are also threatened.
Data: Department of Environment and Primary Industries (Dataset 4)
1.1.7.2.4 Threatening processes
The following potentially threatening processes were collated under the FFG Act. Processes such as alteration to natural flow regimes of rivers and streams, collection of native orchids, degradation of native riparian vegetation along rivers and streams, and fragmentation of habitat are pertinent threats. Introduced plants and animals threaten both terrestrial and aquatic systems through outcompeting and damaging or destroying native biodiversity. In coastal areas, dune degradation resulting from vegetation removal and human impacts threaten biodiversity. In aquatic systems, water quality is threatened by agricultural practices and erosion mechanisms (landslips, gully, sheet rill and river bank erosion) generating sediment and nutrient movement into waterways. In such instances, stream ecology is altered impacting flora and fauna. Grazing or altered hydrology also results in loss of fringing wetland vegetation. Further land clearing poses a major threat to bioregional habitats and biodiversity.
Table 22 Species and ecological communities within the Gippsland Basin bioregion listed as threatened nationally under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). State-listed threatened species under Victoria’s Flora and Fauna Guarantee Act 1988 (the FFG Act) are indicated with a box
Data: Department of Environment and Primary Industries (Dataset 5)
na – Not applicable as species is not listed
NA – Data related to water dependence are not available
a - Species occurs at Corner Inlet Ramsar site
b - Species occurs at the Gippsland Lakes Ramsar site
c - Species occurs at Wilsons Promontory National Park