Bombala
Pest Plants
What the results tell us for Bombala
Bombala Council identified seven weeds as a priority within the council area during the reporting period. All the priority weed species have the potential to reduce primary productivity, while two species are poisonous or potentially harmful to livestock, and one species also has the potential to restrict stock access to water courses. All the priority weed species also have the potential to adversely impact on biological diversity and two threatened ecological communities in the council area. High and medium density infestations of three species decreased during the current reporting period, one species increased, one species remained stable and one species decreased slightly overall.
Council undertook control measures for all priority pest plant species during the reporting period. High and medium infestations of three species, and overall infestations of one species were estimated to have decreased over that time. The NSW Department of Environment and Conservation undertook a range of weed control activities in Kosciuszko National Park and Merriangaah Nature Reserves, often as collaborative programs. No information was available on weeds and weed management in the nine state forests associated with Bombala Council Area.
Pest plant infestations
Seven priority pest plant species were identified in the Bombala Council Area during the reporting period: African Lovegrass (Eragrostis curvula), Blackberry (Rubus fruiticosus), Chilean Needle Grass (Nassella neesiana), English Broom (Cytisus scoparius), Nodding Thistle (Carduus nutans), Serrated Tussock (Nassella trichotoma) and St John's Wort (Hypericum perforatum).
All the priority pest plant species are invasive and have the potential to reduce primary productivity, with St John's Wort also poisonous to stock, and Blackberry potentially able to restrict stock access to water courses. The seven priority species also have the potential to adversely impact on two threatened ecological communities that occur in the council area. The communities are 'Natural Temperate Grasslands of the Southern Tablelands of NSW and the ACT', which is listed as nationally Endangered under the Commonwealth's Environment Protection and Biodiversity Conservation Act 1999, and 'White Box Yellow Box Blakely's Red Gum Woodland communities' which is listed as Endangered under the NSW Threatened Species Conservation Act 1995.
The location, approximate area and density of infestation of the seven major pest plants in Bombala Council Area are summarised in Table 1. In the previous reporting period, high and medium density infestations of Serrated Tussock and St John's Wort were reported to be decreasing and low and scattered plants were either increasing or stable. This trend continued in the current reporting period for these species. In the previous reporting period, high density infestations of African Lovegrass were reported to be increasing, medium density infestations were decreasing and low density and scattered plants were stable. In the current reporting period, areas of medium and high density infestations of African Lovegrass decreased and areas of low density infestations and scattered plants increased. Areas of infestation of Blackberry decreased slightly during the current reporting period, and English Broom remained stable.
Chilean Needlegrass was first detected within the council area in July 2001. The infestation was small (0.5 hectare) and effectively controlled. Since this time, four new infestations have been detected, three of which were on private property and one along a roadside.
| Pest plant species | Location and area of infestations * |
|---|---|
| African Lovegrass (Eragrostis curvula) | Rural land and roadsides within Bombala Council Area. Area of infestation is unknown. |
| Blackberry (Rubus fruticosus (agg. spp)) | Rural land and some roadsides within Bombala Council Area, predominantly in the eastern and southern rainfall areas. Area of infestation is unknown. |
| Chilean Needlegrass (Nassella neesiana) | Rural land and roadsides within Bombala Council Area Medium—2 ha Low—4 ha |
| Nodding Thistle (Carduus nutans) | Rural land within Bombala Council Area. Area of infestation is unknown. |
| Scotch/English Broom (Cytisus scoparius) | Rural land and some small roadside infestations within Bombala Council Area. Area of infestation is unknown. |
| Serrated Tussock (Nassella trichotoma) | Rural land and roadsides within Bombala Council Area. Area of infestation is unknown. |
| St John's Wort (Hypericum perforatum) | Ungrazed urban and rural blocks. A major weed of roadsides in Bombala Council Area. Area of infestation is unknown. |
Source: Bombala Council; * Medium density infestation (50–79% cover); Low density infestation (10–49 % cover).
At least 20 pest plant species were considered a problem in conservation areas within Bombala Council Area during the reporting period (see NSW Government agencies). No information was available regarding the presence of pest plants within the nine state forests located wholly or partially within the council area.
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 (NSW) was made by the NSW Scientific Committee during the current reporting period. The grasses included African Lovegrass and Serrated Tussock, both of which are of concern within the council area. The impacts of exotic perennial grasses outlined in the final determination include (DEC 2004):
- competition with or displacement of native species
- local and regional declines in many native plant species and communities.
Pest plant control activities
NSW Government agencies
The Department of Environment and Conservation (DEC—formerly NSW National Parks and Wildlife Service) undertook control for at least 20 weed species within Kosciuszko National Park and three weed species within Merriangaah Nature Reserve in the council area in the 2003–04 financial year (see Table 2). As no detailed information was provided on the locations of the infestations within Kosciuszko National Park targeted during the 2003–04 financial year, it is not possible to ascertain which control programs were actually located within the Bombala Council Area.
| Location and Pest plant species | Total area treated (ha) | |
|---|---|---|
| Kosciuszko National Park | ||
| African Lovegrass | Unknown | |
| Blackberry | 201 | |
| Broom | Unknown | |
| Cotoneaster (Cotoneaster glaucophyllus) | Unknown | |
| Firethorn (Pyracantha sp.) | Unknown | |
| Fruit Trees | Unknown | |
| Hawthorn (Crataegus monogyna) | Unknown | |
| Hemlock (Conium maculatum) | Unknown | |
| Holly (Ilex aquifolium) | Unknown | |
| Horehound (Marrubium vulgare) | Unknown | |
| Nodding Thistle | Unknown | |
| Pasture grasses | Unknown | |
| Paterson's Curse (Echium spp) | Unknown | |
| Pine (Pinus spp) | Unknown | |
| Poplar (Populus sp.) | Unknown | |
| Serrated Tussock | Unknown | |
| St John's Wort | Unknown | |
| Sweet Briar (Rosa rubiginosa) | Unknown | |
| Tutsan (Hypericum androsaemum) | Unknown | |
| Willow (Salix spp) | Unknown | |
| Yarrow (Achillea millefolium) | Unknown | |
| Merriangaah Nature Reserve | ||
| Blackberry | 10 | |
| Serrated Tussock | 10 | |
| St John's Wort | 10 | |
Source: Department of Environment and Conservation
Control programs undertaken by DEC within Kosciuszko National Park between 2001 and 2003 included the following (NPWS 2001, 2002, 2003):
- control of willows (Salix spp) in the Snowy River valley, in cooperation with Snowy Hydro, the Department of Planning Infrastructure and Natural Resources (formerly Department of Land and Water Conservation), Kosciuszko Alpine Resort and Landcare groups
- whole of catchment control program for willows along the Genoa River, in conjunction with Forests NSW and Parks Victoria
- a Serrated Tussock mapping and control program, with Landcare groups
- mapping of Scotch Broom, with Snowy Hydro, to enable infestations to be located for follow-up control
- commencement of a pro-active search program for Scotch Broom, to identify new infestations after bushfires.
Between 2001 and 2003 DEC also undertook a control program for Serrated Tussock in South East Forests National Park.
No information was available regarding control programs for pest plant species within state forests within the council area.
Bombala Council
The control of all of the priority pest plants within the council area 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. Regional Weed Management plans for the Southern Tablelands and South Coast Region developed during the reporting period, in which the Bombala Council Area is involved, covered 10 pest plant species (see Table 3).
| Pest plant species | Reference |
|---|---|
| African Lovegrass | STSCNPC, 2003a |
| Broom (includes Scotch/English Broom, Cape/Montpellier Broom (Genista monspessulana), Spanish Broom (Spartium junceum)) | STSCNPC, 2002b |
| Blackberry | STSCNPC, 2002a |
| St John's Wort | STSCNPC, 2003d |
| Serrated Tussock | STSCNPC, 2003c |
| Fireweed (Senecio madagascariensis) | STSCNPC, 2003b |
| Chilean Needlegrass (Nassella neesiana) | STSCNPC, 2002c |
| Gorse | STSCNPC, 2002b |
Within the current reporting period, sub-regional plans were prepared for the Monaro sub-region for African Lovegrass, St John's Wort, Vipers Bugloss/Paterson's Curse (Echium plantagineum), Scotch/Nodding Thistles, Horehound and Serrated Tussock. These sub-regional weed management plans were developed in sympathy with the regional weed management plans but override the latter. A sub-regional management plan is currently being developed for the Monaro sub-region for Aquatic Noxious Weeds.
The current sub-regional plans outline management actions for the period from 2003 to 2008. The major objective of all priority weed control programs within the council area is to ensure maximum suppression and destruction of declared noxious weeds on private property and public lands.
Expenditure on and effectiveness of pest plant control
Limited information was available regarding expenditure on control of pest plants within the council area (see Table 4). Control of the three weed species shown in Table 4 was undertaken as part of the sub-regional weed management program. Apart from those for Serrated Tussock, no expenditure figures were available for pest plants for 2000–2003. Overall during the current reporting period high and medium density infestations of these three species were reported to have decreased while low density and scattered infestations increased.
| Pest plant species | Annual expenditure | Source of funding* | |
|---|---|---|---|
| Year | Amount | ||
| St John's Wort (Hypericum perforatum) | 2003–04 | $12,800 | Council and DPI |
| Serrated Tussock (Nassella trichotoma) | 2002–03 | $3,563 | Council (roadsides only) |
| 2003–04 | $2,500 | Council and DPI | |
| African Lovegrass (Eragrostis curvula) | 2003–04 | $15,500 | Council |
Source: Snowy River Council Area; *DPI = Department of Primary Industries—formerly NSW Agriculture
Council reports that persistent drought conditions during the past 11 years have hindered weed control activities within the council area. Drought conditions have placed large financial burdens on landholders, limiting their ability to fund control programs, particularly those long-term programs such as sowing competitive pastures. Drought conditions lessen the effectiveness of this particular approach as competitive pastures thin out making them susceptible to weed invasion. Despite the adverse conditions experienced by landholders within the council area, the majority were maintaining their weed control programs.
About the data
Data were provided by Bombala Council. Information on expenditure for Serrated Tussock, St John's Wort and African Lovegrass was provided by Snowy River Council.
Photographs of scotch broom flower and nodding thistle flower were taken by Jackie Miles and Max Campbell (both images), see http://www.esc.nsw.gov.au/Weeds/ for more.
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.
NPWS—See NSW National Parks and Wildlife Service
NSW National Parks and Wildlife Service (2001) Weed Management Programs 2001, NSW National Parks and Wildlife Service, Hurstville.
NSW National Parks and Wildlife Service (2002) Weed Management Programs 2002, NSW National Parks and Wildlife Service, Hurstville.
NSW National Parks and Wildlife Service (2003) Weed Management 2003, NSW National Parks and Wildlife Service, Hurstville.
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 (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