Harden
Indicator: Pest Plants
Results for this indicator are also available for [an error occurred while processing this directive]
What the results tell us for Harden
Harden Shire Council falls into the area covered by South West Slopes Country Council for control of noxious weeds. There have been nine identified weeds of priority within the Shire. All the priority species have the potential to adversely impact on primary productivity as they are pasture invasive, with four potentially harmful or poisonous to livestock. A number of the priority weeds also have the potential to adversely impact on biodiversity and native vegetation.
During the current reporting period, South West Slopes County Council carried out control activities for all priority weeds, however no information is available on the effectiveness of these control methods for the current reporting period (Table 2. outlines total change in relative abundance and spread (as a % ) resulting from implementation of controls and management plans between 2001 and 2008,over two reporting periods).
No information was available on the status of weeds within various national parks and other reserves over the reporting period, or on weed management activities undertaken by the New South Wales (NSW) Department of Environment and Climate Change (NSW) in those areas. No information was available on weeds or weed management in Young State Forest, of which 2% is located within Harden Shire.
Pest plant infestations
Nine plant species were identified as priority pests in Harden Shire during the reporting period: African Lovegrass (Eragrostis curvula), Blackberry (Rubus fruticosus), Chilean Needle Grass (Nasella neesiana), Fireweed (Senecio madagascariensi), Gorse (Ulex europaeus), Scotch Thistle (Onopordum acanthium), Serrated Tussock (Nassella trichotoma), Silverleaf Nightshade (Solanum elaeagnifolium), and St John's Wort (Hypercum perforatum). All these species have the potential to adversely impact on primary productivity as they are pasture invasive. St John's Wort, Silverleaf Nightshade and Serrated Tussock are also potentially harmful or poisonous to livestock.
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. A number of the priority weed species also have the potential to negatively impact on two threatened ecological communities that occur in the Council area. No information is available to assess the potential impact of these weeds on these threatened plant communities.
The largest infestations were of Scotch Thistle, with significant infestations of Blackberry and St John’s Wort. The location, approximate area and density of infestation of the nine priority species within Harden Shire are summarised in Table 1. Infestations were reported to occur predominantly on grazing lands, with St John's Wort also present along roadsides.
Table 1. Priority pest plant species in Harden Shire, July 2004 to June 2008 (opens in new window)
Pest plants as threatening processes
A number of the priority weed species also have the potential to negatively impact on biodiversity and native vegetation. Harden Shire contains three threatened ecological communities listed as endangered or critically endangered nationally or in NSW (see Ecological communities) (DECC, 2008a; DECC, 2008b; DEWHA, 2008a). (Note: threatened ecological community lists are generated based on Bioregions). White Box Yellow Box Blakely's Red Gum woodland is listed under the NSW Threatened Species Conservation Act 1995, White Box Yellow Box Blakely's Red Gum Grassy Woodlands and Derived Native Grasslands and Natural temperate grasslands of the Southern Tablelands of NSW and the ACT communities is listed as endangered under the Commonwealth's Environment Protection and Biodiversity Conservation Act 1999.
All of these threatened ecological communities are considered at risk from invasive weeds, (DECC, 2008d, DEWHA, 2008a) particularly when existing as small and/or fragmented remnants. These include exotic perennial grasses, pasture weeds, noxious weeds and environmental weeds. Weeds compete with native plants for resources such as light and nutrients, and can aggressively invade areas, displacing native plants and animals. The control of weeds at these priority sites can help recover threatened species. No information is available to assess the impact of weeds on these threatened plant communities.
According to the Department of Environment and Climate Change (DECC) website, there is one priority action under the ‘habitat management: weed control’ recovery strategy in Harden Shire. This action applies to one threatened species, the Eastern Bentwing-Bat (Miniopterus schreibersii oceanensis) (DECC, 2008c).
Pest plant control activities by NSW Government agencies
No information was available regarding control programs undertaken by NSW Government agencies. No figures were available regarding areas of infestation, distribution, expenditure on control programs or changes in distribution due to DECC's control measures. No information was available on control programs for pest plant species within state forests partly located within the Shire.
Pest plant control activities by Harden 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 Noxious Plants Committee is responsible. Regional plans remain active and cover infestations of the seven priority weeds within the Shire. Local Weed Management plans have been in place for over 30years for all weed species, superseded by the Regional Weed Management plans. Two weed species are covered by Local Weed Management plans. Regional Weed Management plans for the Southern Tablelands Region were developed during the reporting period for the pest plant species shown in Table 2.
Table 2. Pest Plant control in Harden Shire, July 2004 to June 2008 (opens in new window)
Control actions for the major weeds within Harden Shire focused largely on prioritising operational and control response, mapping, preventing spread into clean areas, controlling all rare and isolated infestations, strategically reducing infestations in marginal and core areas, implementing protocols to prevent seed spread, education and extension, facilitating coordination between land managers, continually monitoring major roadways such as Hume Highway for isolated outbreaks, and protecting vulnerable high conservation areas.
Weed control methods used within the Shire predominantly involved the use of herbicide. Other methods used included some slashing for African Lovegrass, manual removal and burning for Chilean Needlegrass and Gorse, and biological control methods were used in conjunction with other methods to control Blackberry and St John’s Wort.
Expenditure on and effectiveness of pest plant control
The majority of funding for control of nine of priority weed species was sourced either through Council and/or NSW DPI funding, with an National Heritage Trust Grant for the control of Blackberry in 2005/06. No figures were available for expenditure during the current reporting period on weed control by community groups or individuals.
During the current reporting period, no information was available to assess the effectiveness resulting from implementation of controls and management plans for priority weeds.
No information was available for the percentage of total area treated for each of the nine priority weeds treated by community groups.
About the data
A spread sheet was supplied to each Council, with fields summarising priority plant species, the status of control plans and their objectives. The spreadsheet also included a field nominating the types of control methods used and the areas that were treated, either by community groups, individuals or local government. A field describing the change in relative abundance within the density classes of high (75-100% cover), medium (20-74% cover) and low (1-19%) was also included. In compiling the Pest Plant indicator chapters, the authors compared this data to data for the previous reporting period (2000-2004), as well as sourcing information available on the DECC website. In some cases, missing data impeded comparison.
References
Department of Environment and Climate Change (2008b), Threatened Species – species, populations and ecological communities in NSW , search on endangered ecological community, viewed 29 September 2008, http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/home_species.aspx
Department of Environment and Climate Change (2008c), Threatened Species – species, populations and ecological communities in NSW , Recovery and threat abatement, Harden Shire Council, viewed 13 October 2008, http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/pas_lga_recovery_details.aspx?
lga=Bega%20Harden%20Shire%20Council&type=habitat+management:+weed+control
Department of Environment, Water, Heritage and the Arts (Commonwealth) (2008a), Biodiversity, search on endangered ecological community, viewed 29 September 2008, http://www.environment.gov.au/biodiversity/index.html
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 29 September 2008,
STSCNPC—see Southern Tablelands and South Coast Noxious Plants Committee
