Eurobodalla
Indicator: Pest Plants
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What the results tell us for Eurobodalla
Eurobodalla Shire Council identified 16 weeds of priority within their Shire. Infestation areas of one species increased significantly during the reporting period, while areas of infestation decreased for eight species. All of the priority weed species have the potential to adversely impact on biological diversity and native vegetation. Many of these weeds also have the potential to reduce primary productivity. Four are also poisonous or potentially harmful to livestock, while one has the potential to impact on native aquatic ecosystems within the Shire.
The Shire Council carried out weed control activities for all 16 priority weeds during the reporting period, and achieved significant reductions for some species. No information was available on control activities undertaken by the New South Wales (NSW) Department of Environment and Climate Change (DECC) within various national parks and other reserves in the Shire over the reporting period. No data were available on weeds or weed management in the 15 state forests located wholly or partly within the Shire.
Pest plant infestations
Sixteen priority pest plants were identified in Eurobodalla Shire: African Lovegrass (Eragrostis curvula), Bitou Bush (Chrysanthemoides monilifera), Blackberry (Rubus fruticosus), Chilean Needle Grass (Nassella neesiana), Fireweed (Senecio madagascariensis), Giant Parramatta Grass (Sporobolus fertilis), Groundsel Bush (Baccharis halimifolia), Lantana (Lantana camara), Pampas Grass (Cortaderia sp.), Patersons Curse (Echium spp), Prickly Pear (Opuntia spp), Salvinia (Salvinia molesta), Scotch Broom (Cytisus scoparius), Serrated Tussock (Nassella trichotoma) and St John's Wort (Hypericum perforatum).
All of the priority weed species have the potential to adversely impact on biological diversity and native vegetation and many have the added potential to reduce primary productivity. St John's Wort, Fireweed Groundsel Bush and Patersons Curse are also poisonous or potentially harmful to livestock. Salvinia has the potential to impact on native aquatic ecosystems, including creeks and wetlands, and to infest farm dams within the Shire. The location, approximate area and density of infestation of the priority pest plant species in the Shire are summarised in Table 1.
Table 1. Priority Pest Plants in Eurobodalla Shire, July 2004 to June 2008 (opens in new window)
African Lovegrass increased in area during the reporting period by 25% in low and scattered infestations. Fireweed infestations appeared to remain the same as the last reporting period, except for scattered infestations which was not determined. This report is positive as significant increases for Fireweed were documented in the previous reporting period. Both of these weeds are on the increase within large areas of southern NSW. Serrated Tussock decreased in areas of medium and low density, however remained unchanged in areas of high density.
Giant Parramatta Grass was reported to have shown no change in abundance in low to high density infestations, however scattered plants were not found. Bitou Bush and Lantana, both listed as threatening processes to biodiversity, were reported to have been reduced during the current reporting period. Lantana decreased 25% in scattered, low and medium densities, and by 20% in high density infestations. Bitou Bush decreased by 100% in medium and high density infestations, and by 75% and 50% in low and scattered densities respectively.
Salvinia, a serious waterweed, reduced by an estimated 50% in high density infestations, and by 100% in medium and low density infestations. This report is positive as Eurobodalla has a RAMSAR listed wetland and nine wetlands of national significance.
No information was available to assess the distribution and abundance of priority weeds within conservation areas. No information was available regarding the presence of pest plants within state forests located wholly or partially within the Shire.
Pest plants as threatening processes
A number of the priority weed species also have the potential to negatively impact on biodiversity and native vegetation. Eurobodalla Shire may contain 12 threatened ecological communities listed as endangered or critically endangered within NSW or nationally (DECC, 2008a; DECC, 2008b; DEWHA, 2008a). (Note: threatened ecological community lists are generated based on Bioregions). Eleven threatened communities are listed under the NSW Threatened Species Conservation Act 1995, one is listed under the Commonwealth's Environment Protection and Biodiversity Conservation Act 1999.
Most (possibly 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 DECC threatened species website, there are 12 priority actions under the "habitat management: weed control" recovery strategy in the Eurobodalla Shire Council. These actions apply to 12 threatened species, populations and communities, including four Endangered Ecological Communities (DECC, 2008e). The impacts of a number of weed species such as Bitou Bush (Chrysanthemoides monilifera) are identified as Key Threatening Processes. The control of weeds at these priority sites can help recover threatened species.
Invasion of native plant communities by Bitou Bush and Boneseed' was listed as a threatening process under the Threatened Species Conservation Act 1995 in the previous reporting period. The impacts of Bitou Bush as outlined in the final determination made by the Scientific Committee include (DECC 2008b):
- local and regional declines in many native plant species and communities
- alteration of structure and habitat for native vertebrate and invertebrate species, favouring proliferation of non-indigenous species.
A draft threat abatement plan was during the previous reporting period for Bitou Bush. This plan provides a collaborative strategy for Bitou Bush control and monitoring programs for the primary purpose of conserving threatened species in NSW (DECC 2008a).
A priority action to conserve threatened ecological communities includes the undertaking of weed control for Bitou Bush and Boneseed at priority sites in accordance with the approved Threat Abatement Plan and associated PAS actions. This priority action applies to the following threatened ecological communities. Freshwater wetlands on coastal floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions, Littoral Rainforest in the NSW North Coast, Sydney Basin and South East Corner Bioregions and Swamp oak floodplain forest of the NSW North Coast, Sydney Basin and South East Corner bioregions. To view other priority actions for threatened species, populations and communities relating to weeds, refer to (DECC, 2008d).
Pest plant control activities by NSW Government agencies
No information was available regarding control programs undertaken by NSW Government agencies. No information was available regarding control programs for pest plant species within state forests located in Eurobodalla Shire.
Pest plant control activities by Eurobodalla Shire Council
The control of pest plants within the Shire is undertaken either according to Regional Weed Management Plans or local plans. The Regional Weed Management Plans cover the area for which the Southern Tablelands and South Coast Noxious Plants Committee is responsible. The coastal group of Councils seeks funding from the Department of Primary Industries (DPI) (formerly NSW Agriculture) and the respective Councils for the implementation of the relevant management plans.
The South Coast Regional Bitou Bush Strategy, which was developed during the reporting period, is applicable within the Australian Capital Region to the coastal areas of Bega Valley and Eurobodalla Shires (see Broese and Wolfenden, 2001).
The South Coast Regional Bitou Bush Strategy, which was developed during the previous reporting period, is applicable within the Australian Capital Region to the coastal areas of Bega Valley (see Broese and Wolfenden, 2001). Regional weed management plans for the South Coast Region developed during the reporting period covered three priority pest plant species in Eurobodalla, while regional weed management plans remained active for a further nine pest plant species for the Shire (see Table 2).
Table 2. Pest plant control in Eurobodalla Shire, July 2004 to June 2008 (opens in new window)
Control actions for the major weeds within Eurobodalla Shire focused largely on preventing or restricting spread into uninfested areas, and containing, controlling and/or eradicating all rare, isolated and new infestations. The Shire Council aimed to eradicate new infestations of Giant Parramatta Grass, Goundsel Bush and Chilean Needle Grass within two months of detection and Lantana within six months. Weed control methods predominantly involved the use of herbicide, with some mechanical and manual removal. Biological control methods were used in conjunction with other methods to control Lantana, Bitou Bush and Prickly Pear.
No infestations of Chilean Needlegrass have been detected to date within the Shire. However, control actions are in place for this plant and involve inspections for its presence.
Expenditure on and effectiveness of pest plant control
Bitou Bush control was jointly funded by the Shire Council and the DPI. The majority of funding for controlling another 11 priority species was sourced either through the Shire Council and/or the Department of Primary Industries. Control programs for the remaining four species were funded solely through the Shire Council's budget. The Shire Council received funds from the National heritage Trust for the control of bitou bush. The Shire Council also used funds collected through its Environment Fund levy to support weed control activities.
The majority of funding for weed control within the Shire was expended on Bitou Bush, Blackberry, Fireweed and Lantana. This resulted in a 100% reduction in high and medium density infestations of Bitou Bush had the greatest reduction in area due to control works, decreasing by 75% and 50% in low and scattered densities respectively. Lantana decreased by 25% in scattered, low and medium densities, and by 20% in high density infestations. Fireweed infestations remained the same during the reporting period, after increasing significantly during the previous reporting period. Salvinia reduced by an estimated 50% in high density infestations, and 100% in medium and low density infestations.
The area of Blackberry decreased by 50% in scattered plants, and were not found at higher densities during the current reporting period. Similarly scattered plant infestations of Patterson's Curse were reduced by 30%. Scattered plant infestations of Prickly Pear were reduced in area by 10% and scattered plants by 10%. The area of scattered plants of Pampas Grass was also reduced by 10%. African Lovegrass increased in area during the reporting period by 25% in low and scattered infestations.
No information was available regarding control measures taken by individuals (such as farmers) or community groups for other priority pest plant species.
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
DECC—see Department of Environment and Climate Change
Department of Environment and Climate Change (2008a) Draft NSW Threat Abatement Plan—Invasion of native plant communities by bitou bush/boneseed (Chrysanthemoides monilifera), Department of Environment and Conservation, Hurstville, viewed 29 September 2008, http://www.nationalparks.nsw.gov.au/PDFs/TAP_draft_BitouBush_Boneseed.pdf
Department of Environment and Climate Change (NSW) (2008b) NSW Scientific Committee—Final Determination, Invasion of Native Plant Communities by Bitou Bush and Boneseed—Key Threatening Process Declaration, NSW Department of Environment and Conservation, viewed 29 September 2008, "http://www.nationalparks.nsw.gov.au/npws.nsf/Content/Invasion+of+native+plant+
communities+by+bitou+bush+and+boneseed+key+threatening+process+declaration
Department of Environment and Climate Change (2008c), 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 (2008d), Threatened Species – species, populations and ecological communities in NSW , Recovery and threat abatement, Eurobodalla Shire Council, viewed 13 October 2008, http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/pas_lga_
recovery_details.aspx?lga=Bega%20Eurobodalla%20Shire%20Shire Council&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
