Semi-evergreen Vine Thicket

Semi-evergreen Vine Thicket is the name given to the threatened ecological community Semi-evergreen Vine Thickets of the Brigalow Belt (South) and Nandewar Bioregions. It is a semi-arid form of dry rainforest dominated by a diversity of non-eucalypt trees and shrubs such as Native olive (Notelaea microcarpa), Wilga (Geijera parviflora) and Peach bush (Ehretia membranifolia) with numerous vine species present.

Unfortunately large areas of this community have been cleared across our catchments and remaining fragments are listed as endangered. The community provides an essential home to many of our catchments' most threatened species.

Semi-evergreen Vine Thicket is listed as a threatened ecological community under both the Australian Government's Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and the NSW Threatened Species Conservation Act 1995 (TSC Act).

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Where does the community occur?

Semi-evergreen Vine Thicket is found on both private and public land on the slopes and the eastern parts of the plains. It occurs on rocky hills and gullies, on light clays on hillsides and on sandy clay loams with gravel on low rises on the plains.

While predominantly a Queensland community, Semi-evergreen Vine Thicket occurs in northern NSW in the Border Rivers-Gwydir and Namoi catchments. Semi-evergreen Vine Thicket is common around Terry Hie Hie, Bingara and Yetman.

Identification

Semi-evergreen Vine Thicket has an uneven canopy which is 4-12 m high, dominated by a range of different species. Common dominant species in the catchment include Native olive, Wilga, Peach bush, Red olive plum (Elaeodendron australe) and Red ash (Alphitonia excelsa).

The community may also have emergent species such as Silver-leaved ironbark (Eucalyptus melanophloia), Belah (Casuarina cristata) or White cypress pine (Callitris glaucophylla). There is usually a high diversity of shrubs with sparse grasses and herbs. A range of vine species are usually present. Most patches of the community in NSW are less than 1 ha.

What is not Semi-evergreen Vine Thicket?

Semi-evergreen Vine Thicket does not occur on floodplains or on the tablelands. Many species occurring in Semi-evergreen Vine Thicket also occur as understorey in adjoining communities (such as Weeping Myall, Belah Forest and Brigalow).

Threats

Semi-evergreen Vine Thicket is threatened with extinction or continued decline from a number of historical and current sources.

Clearing – broad scale clearing was the major threat to this community in the past but it has ceased to be a threat in NSW with the introduction of the Native Vegetation Act.

However, removal of small fragments, clearing along fencelines, tracks and roadsides, and clearing for mining development and exploration remains a significant threat.

Fire – semi-evergreen Vine Thicket is naturally resistant to fire when in good condition, but in heavily grazed or weedy patches the threat from fire is greatly increased. It is slow to regenerate from fire, and may not recover if invaded by weeds after a fire. Exotic pastures adjacent to thickets can increase the intensity of fires.

Grazing – domestic stock will affect the composition of the understorey in Semi-evergreen Vine Thicket, although the impact is likely to be greatest in degraded patches or small fragments. Sheep, cattle and horses can also prevent seed regeneration by eating new seedlings. Goats, horses and other browsing animals will cause more damage than sheep or cattle by eating a wider range of species. Feral pigs may also cause damage by grazing and trampling ground layer plants. Disturbance by grazing animals will increase the likelihood of invasion by weeds.

Weeds – grassy weeds such as Buffel grass (Cenchrus ciliaris), Coolatai grass (Hyparrhenia hirta) and Green panic (Megathyrsus maximus var pubiglumis) pose a threat to Semi-evergreen Vine Thicket by increasing the risk of fire and by displacing other ground layer species. These species will normally be a problem in damaged or sparse patches but are capable of invading undisturbed patches. Other weeds of significance in the catchment include Prickly pear (Opuntia stricta var stricta) and African boxthorn (Lycium ferocissimum).

Climate change – is likely to have an effect on distribution and composition of Semi-evergreen Vine Thicket and increase the impact of other threats, particularly fire and weeds.

Management

The aim of management of Semi-evergreen Vine Thicket is to maintain or increase the extent and condition of the community.

Maintain large areas with buffers to prevent fire. Brigalow community makes a good buffer as it is more fire resistant and does not include a lot of grass. Mow, spray or plough fire breaks around edges adjacent to eucalypt or grass communities. Develop a fire management plan to strategically reduce the risk of fire reaching patches.

Retain all remaining patches and where possible change fence lines and road alignment to prevent new clearing. Avoid tidying up around the edges of existing patches. Where possible, leave a buffer around the edge of existing patches to encourage regeneration and expansion of the patch.

Provide long-term protection for Semi-evergreen Vine Thicket through Agreements with the CMA or Conservation Agreements with the Office of Environment and Heritage or the Nature Conservation Trust.

Establish new stands of Semi-evergreen Vine Thicket through revegetation and assisted regeneration or reconnect existing stands. Many species will re-establish by seed distributed by birds, so use easily established compatible species such as Cooba (Acacia salicina) to establish a canopy. Select species to match the type of Semi-evergreen Vine Thicket that you have. Look at existing patches to pick suitable species. Collect seed locally and use within one year after storing in a cool environment. Seek advice from the CMA for revegetation.

Manage grazing to prevent damage to existing plants and to allow flowering, seed set and germination. Fence patches to control the access grazing animals have to patches, particularly goats and horses.

Control feral pigs and goats in patches through baiting, shooting or trapping.

Control weeds in and around Semi-evergreen Vine Thicket patches, particularly exotic pasture species. Maintain a grass free buffer around existing patches. Act quickly to identify and control new outbreaks of weeds in and around patches.

Ecosystem function: how healthy woodlands work for you

Healthy Semi-evergreen Vine Thicket provides a wide range of benefits that are called 'ecosystem services'. These include:

  • financial benefits
  • soil formation and cycling
  • nutrient cycling
  • water capture, filtration and delivery to water bodies
  • pollination
  • pest management (e.g. reducing pest pressure on crops)
  • regional climate buffering
  • shade and shelter (e.g. for livestock)
  • breakdown and absorption of wastes
  • a sense of place
  • scenery

Further Information

Look for "Semi-evergreen Vine Thicket" on the EPBC Species Profiles and Threats database (SPRAT) at
www.environment.gov.au/biodiversity/threatened/index.html.

National recovery plan for semi-evergreen vine thickets of the Nandewar and Brigalow
Belt (South and North) bioregions
www.environment.gov.au/biodiversity/threatened/publications/recovery/pubs/semi-evergreen-vine-thickets.pdf

The listing for this community under the NSW Threatened Species Conservation Act
can be found at
www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10749

Contact the Border Rivers-Gwydir Catchment Management Authority at 02 6728 8020 or visit our website at www.brg.cma.nsw.gov.au

 

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