State of the Environment Report title
2 0 0 4

2004 Report



Young

Pest Plants

Indicator description

Results for this indicator are also available for  

What the results tell us for Young

photo of blackberry, credit: Jackie Miles and Max Campbell, http://www.esc.nsw.gov.au/Weeds/

Young Shire Council identified seven weeds of priority within the shire. Infestations of six priority species decreased in area during the current reporting period and infestations of one other species remained relatively stable. All the priority species have the potential to adversely impact on primary productivity as they are pasture invasive, with four being potentially harmful or poisonous to livestock.

Council carried out weed control activities for all seven priority weeds during the reporting period, and achieved significant reductions in densities for most of the species. The NSW Department of Environment and Conservation undertook activities to control two weed species in nature reserves over the reporting period. No data were available on weeds or weed management in the 23 state forests located wholly or partly within the shire.

Pest plant infestations

photo of scotch thistle flower, credit: Jackie Miles and Max Campbell, http://www.esc.nsw.gov.au/Weeds/

Seven plant species were identified as pests in Young Shire during the reporting period: Blackberry (Rubus fruticosus), Scotch Thistle (Onopordum acanthium), Serrated Tussock (Nassella trichotoma), Silverleaf Nightshade (Solanum elaeagnifolium), St John's Wort (Hypercum perforatum), Sweet Briar (Rosa rubiginosa) and Wild Radish (Raphanus raphanistrum). All the priority species have the potential to adversely impact on primary productivity as they are pasture invasive. St John's Wort, Silverleaf Nightshade, Wild Radish and Serrated Tussock are also potentially harmful or poisonous to livestock.

The location and approximate area and density of infestation of the seven major pest plants in Young Shire are summarised in Table 1. Infestations were reported to occur predominantly in grazing lands, with St John's Wort also present along roadsides. Six priority species were reported to have decreased since the last reporting period, while the seventh (Silverleaf Nightshade) remained stable.

Table 1. Priority pest plant species in Young Shire, July 2000 to June 2004
Pest plant speciesLocation and area of infestations *
Blackberry
(Rubus fruticosus)
Hilly country and along waterways.
Infestations cover approximately 2% of the shire and are at the following densities:
High—100 hectares
Medium—1,000 hectares
Low—2,000 ectares
Scattered plants—2,000 hectares
Scotch Thistle
(Onopordum acanthium)
Fertile grazing or cropping land.
Infestations cover approximately 5% of the shire and are at the following densities:
High—1,000 hectares
Medium—1,000 hectares
Low—2,000 hectares
Scattered plants—10,000 hectares
Serrated Tussock
(Nassella trichotoma)
Railway corridor.
Infestations cover less than 0.1% of the shire and are at the following densities:
Scattered plants—10 hectares
Silverleaf Nightshade
(Solanum elaeagnifolium)
Isolated to one major infestation at Young.
Infestations cover approximately 0.2% of the shire and are at the following densities:
High—50 hectares
Medium—75 hectares
Low—75 hectares
Scattered plants—20 hectares
St John's Wort
(Hypercum perforatum)
Unsupered and ungrazed land, roadsides and reserves.
Infestations cover approximately 0.8% of the shire and are at the following densities:
High—50 hectares
Medium—500 hectares
Low—500 hectares
Scattered plants—1,000 hectares
Sweet Briar
(Rosa rubiginosa)
Hillier high country.
Infestations cover approximately 0.6% of the shire and are at the following densities:
Medium—100 hectares
Low—500 hectares
Scattered plants—1,000 hectares
Wild Radish
(Raphanus raphanistrum)
Cropping lands within the shire.
Infestations cover approximately 1.5% of the shire and are at the following densities:
High—45 hectares
Medium—45 hectares
Low—175 hectares
Scattered plants—175 hectares

* Note: High density infestation (80–100% cover); Medium density infestation (50–79% cover); Low density infestation (10–49 % cover); Scattered plants (less than 10% cover); Source: Southern Slopes Noxious Plants Authority

Dananbilla Nature Reserve and 63% of Koorawatha Nature Reserve occur within the shire. Weeds recorded by the Department of Environment and Conservation (DEC—formerly NSW National Parks and Wildlife Service) within Dananbilla Nature Reserve included Paterson's Curse (Echium sp.), Thistles, Willows (Salix spp) and Capeweed (Arctotheca calendula). Paterson's Curse occurred over 10% of Dananbilla Nature Reserve, while the other species covered less than 2.5% each. Weeds recorded by DEC within Koorawatha Nature Reserve included St John's Wort, Tree of Heaven (Ailanthus altissima), Paterson's Curse, Thistle, pasture grasses, Spiny Burr-grass (Cenchrus longispinus), African Boxthorn (Lycium ferocissimum) and Peppertree (Schinus areira). Coverage of these species within Koorawatha Nature Reserve varied from 0.01% to 5% of the reserve area.

The majority of Bendick Murrell State Forest and Young State Forest occur within Young Shire. No information was available regarding the presence of pest plant species within these areas.

Pest plants as threatening processes

A final determination to list 'Invasion of native plant communities by exotic perennial grasses' as a key threatening process under the Threatened Species Conservation Act 1995 was made by the NSW Scientific Committee during the current reporting period. The grass species included Serrated Tussock, which is a species of concern within Young Shire. The impacts of exotic perennial grasses outlined in the Scientific Committee's final determination include (DEC 2004):

Pest plant control activities

NSW Government Agencies

In the 2003–04 financial year, DEC undertook control programs for Paterson's Curse and St John's Wort within Dananbilla Nature Reserve and Paterson's Curse within Koorwatha Nature Reserve. No information was available regarding expenditure or effectiveness of control measures.

No information was available on control programs for pest plant species within Bendick Murrell or Young state forests.

Young Shire Council

The control of pest plants within the shire is undertaken according to Regional and Local Weed Management Plans. Regional Weed Management plans cover the area for which the Southern Tablelands and South Coast Noxious Plants Committee is responsible. Local weed management plans were prepared in 2002 and 2003 to target local infestations of the seven priority weeds within the shire. Control programs for the seven priority weeds have been in place within the shire for the last 30 years.

Regional Weed Management plans for the Southern Tablelands and South Coast Region were developed during the reporting period for the pest plant species shown in Table 2.

Table 2. Pest plants for which regional weed management plans were prepared, July 2000–June 2004
Pest plant species Reference
African LovegrassSTSCNPC, 2003a
Alligator Weed (Alternanthera philoxeroides),STSCNPC, 2001a
Bitou Bush (Chrysanthemoides monilifera)STSCNPC, 2002e
Blackberry (Rubus fruticosus)STSCNPC, 2002a
Broom (includes Scotch/English Broom (Cytisus scoparius), Cape/ Montpellier Broom, Spanish Broom (Spartium junceum))STSCNPC, 2002b
Cabomba (Cabomba spp)STSCNPC, 2001a
Chilean Needlegrass (Nassella neesiana)STSCNPC, 2002c
Fireweed (Senecio madagascariensis)STSCNPC, 2003b
Gorse (Ulex europaeus)STSCNPC, 2002b
Groundsel Bush (Baccharis halimifolia)STSCNPC, 2002d
Horsetail (Equisetum spp)STSCNPC, 2001a
Lagarosiphon (Lagarosiphon major)STSCNPC, 2001a
Lantana (Lantana camara)STSCNPC, 2001b
Salvinia (Salvinia molesta)STSCNPC, 2001a
Senegal Tea Plant (Gymocoronis spilanthoides)STSCNPC, 2001a
Serrated Tussock (Nassella trichotoma)STSCNPC, 2003c
St John's Wort (Hypericum perforatum)STSCNPC, 2003d
Water Hyacinth (Eichhornia crassipes)STSCNPC, 2001a
Water Lettuce (Pistia stratiotes)STSCNPC, 2001a

Priority control actions for the major weeds within the shire included:

Weed control methods used within the shire predominantly involved the use of herbicide. Other methods used included cultivation and pasture establishment (Serrated Tussock), mechanical removal and burning (Blackberry) and physical removal (Sweet Briar). Biological control methods were also used in conjunction with other methods to control Scotch Thistle.

Expenditure on and effectiveness of pest plant control

Expenditure on weed control and outcomes of control programs for selected priority pest plant species within the shire is summarised in Table 3. The majority of funding for weed control was sourced through council and the Department of Primary Industries (DPI—formerly NSW Agriculture) during the 2000–03 financial years, and was expended on Serrated Tussock (10 ha treated by council) and St John's Wort (2,000 ha treated by council). DPI provided no funding in 2003–04. Because of this, the Noxious Plants Authority was required to expend additional funding from its contract budget; control efforts remained largely equivalent to that in the previous three financial years. Blackberry control within the shire was also partially funded through Natural Heritage Trust grants.

Table 3. Pest plant control in Young Shire, July 2000 to June 2004
Annual expenditure on controlling pest plant speciesOutcome: Change in abundance or spread from levels in 2001Total Area treated (ha) #
YearAmount*Source of funding
Blackberry (Rubus fruticosus)
2000–01$10,000Council, DPI and NHTHigh density infestations—10% reduction
Medium density infestations—5% reduction
Low density infestations—20% reduction
Scattered plants—50% reduction
1,550 ha
(30% of infested area)
2001–02$10,000
2002–03$10,000
2003–04$2,000
Scotch Thistle (Onopordum acanthium)
2000–01$12,000Council and DPIMedium density infestations—5% reduction
Low density infestations—10% reduction
Scattered plants—20% reduction
2,000 ha
(14% of infested area)
2001–02$10,000
2002–03$8,000
2003–04$1,400
Serrated Tussock (Nassella trichotoma)
2000–01$1,000Council and DPIScattered plants—40% reduction10 ha
(100% of infested area)
2001–02$20,000
2002–03$20,000
2003–04$100
Silverleaf Nightshade (Solanum elaeagnifolium)
2000–01$2,500Council, DPI and NHTAll populations remain stable.440 ha
(100% of infested area)
2001–02$2,500
2002–03$2,000
2003–04$2,000
St Johns Wort (Hypercum perforatum)
2000–01$20,000Council and DPIHigh density infestations—10% reduction
Medium density infestations—5% reduction
Low density infestations—10% reduction
Scattered plants—10% reduction
2,000 ha
(98% of infested area)
2001–02$20,000
2002–03$20,000
2003–04$20,000
Sweet Briar (Rosa rubiginosa)
2000–01$3,000Council and DPIHigh density infestations—no reduction
Medium density infestations—5% reduction
Low density infestations—5% reduction
Scattered plants—10% reduction
500 ha
(31% of infested area)
2001–02$3,000
2002–03$2000
2003–04$400
Wild Radish (Raphanus raphanistrum)
2000–01$1,500Council, DPI and NHTAll infestations have undergone minor decreases due to drought440 ha(90% of infested area)
2001–02$1,500
2002–03$1,500
2003–04$1,500

# Total area includes area covered by control works undertaken by council and community groups only; * Funding includes only expenditure by the Southern Slopes Noxious Plants Authority on behalf of council on their roadsides and reserves within the shire; it does not include expenditure on contractors or individuals to undertake weed control outside these areas; Source: Southern Slopes Noxious Plants Authority

Despite funding for weed control within the shire decreasing dramatically in the 2003–04 financial year, the majority of the priority pest plants experienced reductions within the current reporting period. Minor reductions were due to the effects of drought.

The pest plants that had the greatest reduction in area due to control works were:

Council undertook control measures for all species, with community groups undertaking additional works (50 ha) for Blackberry. No information was available regarding control works undertaken by individuals such as farmers for any of the priority pest species.

About the data

Data were provided by Southern Slopes Noxious Plants Authority.

The Southern Slopes Noxious Plants Authority's data collection and reporting methodology for pest plants greatly improved over the current reporting period due to the introduction of Regional Weed Management plans. When comparing figures for area of infestation from the previous reporting period with the current period, some priority weeds in the shire (such as Blackberry and St John's Wort) appeared to have increased dramatically. This, however, is not the case: increased monitoring and data collection identified greater areas of infestation, and showed false increases in areas of infestation which were not apparent on the ground. Because of this effect, data for the previous reporting period was used as a rough baseline only, and actual reported increases were relied upon to assess the current state of pest plants within the shire.

Data collected for the Ecologically Sustainable Forest Management Program 2003–04 financial year were provided by DEC South West Slopes Region.

Photographs were taken by Jackie Miles and Max Campbell (see http://www.esc.nsw.gov.au/Weeds).

References

DEC—see Department of Environment and Conservation (NSW)

Department of Environment and Conservation (NSW) (2004) NSW Scientific Committee—Final Determination, Invasion of Native Plant Communities by Exotic Perennial Grasses—Key Threatening Process Declaration, NSW Department of Environment and Conservation, viewed 3 February 2005, http://www.nationalparks.nsw.gov.au/npws.nsf/Content/Invasion+of+native+plant+communities+by+exotic+perennial+grasses+key+threatening+process+declaration.

Southern Tablelands and South Coast Noxious Plants Committee (2001a) Regional Weed Management Plan for Aquatic Noxious Weeds 2001–2006, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/Fwortregionalplan.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2001b) South Coast Lantana Management Plan 2001–2005, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/Lantana.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2002a) Blackberry Regional Management Plan 2002–2007, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/BlackberryRMP02–07.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2002b) Broom and Gorse Regional Management Plan 2002–2007, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/BroomRMP02–03.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2002c) Chilean Needle Grass Regional Weed Management Plan 2002–2007, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/Chileanneedlegrass.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2002d) Groundsel Bush Regional Weed Management Plan 2002–2007, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/Groundselbush.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2002e) South Coast Bitou Bush Management Plan 2002–2007, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/BitouRMP02–07.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2003a) African Lovegrass Regional Management Plan 2003–2008, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/AfricanLovegrassfinal.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2003b) Fireweed Regional Weed Management Plan 2003–2008, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/fireweedplan.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2003c) Serrated Tussock Regional Weed Management Plan 2003–2008, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/FSerratedtussockweedplan.pdf.

Southern Tablelands and South Coast Noxious Plants Committee (2003d) St John's Wort Regional Management Plan 2003–2008, Southern Tablelands and South Coast Noxious Plants Committee, viewed 5 January 2005, http://www.esc.nsw.gov.au/Weeds/Fwortregionalplan.pdf.

STSCNPC—see Southern Tablelands and South Coast Noxious Plants Committee