Plant Protection Quarterly Vol.15(4) 2000 169 The broom containment program is re- vised and implemented on an annual ba- Controlling broom (Cytisus scoparius (L.) Link) in sis. Current control techniques have natural ecosystems in Barrington Tops National Park evolved to minimize environmental im- pact. Since implementation of the contain-

A B ment program in the late 1980s broom has Mellesa Schroder and Chris Howard been successfully contained along con- A National Parks and Wildlife Service, Hunter Region, Locked Bag 99, Nelson tainment lines within the National Park, Bay, New South Wales 2315, Australia. however this has not prevented an in- B Barrington Tops National Park, National Parks and Wildlife Service, PO Box crease in density of broom within the 236, Gloucester, New South Wales 2422, Australia. main infestation. The containment pro- gram has been successful in treating iso- lated infestations and protecting unaf- Summary fected catchments. Isolated broom plants In 1996 the New South Wales National established in woodlands and open forest in the Gloucester Tops area subalpine en- Parks and Wildlife Service (NPWS) de- dominated by Eucalyptus pauciflora Sieber vironment (separated from the infested veloped a formal management strategy ex Spreng. with occurrences of other spe- area on the Barrington Tops by a forested for broom containment in Barrington cies such as E. stellulata Sieber ex DC. and area at slightly lower altitude) have been Tops National Park. This strategy was E. dalrympleana Maiden (NPWS 1989). removed as part of this program. based on a review of the 1987 contain- Since the 1980s broom has also began to When the containment strategy was ment strategy developed by the NPWS in infest both the edge of subalpine wetlands implemented it was recognized that the association with the Broom Council. The and the open plains of the plateau (M. only long term solution to reducing the strategy recognizes the impact of broom Newton personal communication). Veg- size of the main infestation appeared to be on the natural ecosystem and aims to en- etation communities below the Barrington establishment of suitable biological con- sure annual implementation of an effec- Tops plateau within the National Park are trol agents. The Broom Council in the tive containment program without com- dominated by subtropical rainforest, 1980s campaigned for funding to under- promising natural values of the area by warm temperate rainforest, beech forest take research into biological control causing further impacts on this sensitive (Nothofagus moorei (F.Muell.) Krasser) and (Adams 2000). subalpine environment. wet and dry sclerophyll forests. Whilst rainforests do not provide conditions suit- Broom management strategy for Introduction able for the establishment of broom, large Barrington Tops National Park Broom (Cytisus scoparius (L.) Link) has be- disturbed areas and drainage lines within The NPWS is developing control strate- come a major weed on the Barrington rainforests, where there is more light, may gies for all major weeds in National Parks Tops plateau (including Barrington Tops provide suitable conditions. Dry sclero- across New South Wales. In 1996 the National Park) since it was first intro- phyll forests at high altitude also provide NPWS developed a ‘Scotch Broom Man- duced as a garden plant on the property suitable open conditions for broom estab- agement Strategy’ which includes an an- ‘Tomalla’, at the northern end of the pla- lishment. nual works program based on the original teau, in the 1840s. Broom was recognized Broom control was initiated as early as containment program. No review had as a major weed by 1964 and its spread 1972 in Barrington Tops National Park. been undertaken since the original con- was associated with grazing, fire and log- Experimental plots were established to tainment program was developed in 1987 ging trails throughout the plateau (Water- trial various control methods including and the annual works program had suf- house 1988). clearing, fire and a range of chemicals (M. fered from limited resources. Barrington Tops National Park con- Newton personal communication). Early The strategy was developed to ensure serves about 80 000 hectares of rugged control methods involved large scale her- an integrated approach to containing the landscapes varying in altitude from 1585 bicide spraying. This method was largely infestation. The strategy incorporates the m above sea level (asl) on the Barrington ineffective as it involved a high degree of following objectives: Tops plateau down to 170 m asl at Chich- disturbance to native vegetation and soils 1. Contain and treat broom within the ester Dam. This large altitudinal range which in turn promoted broom seed ger- existing infestation. Broom is control- combined with a mosaic of geology, soils, mination. There were also concerns about led along roadways, walking tracks rainfall and aspects provide a diversity of the safety of spray operators using such and recreational areas to minimize vegetation communities and faunal habi- large amounts of herbicides. spread into non-infested area. The tats. Vegetation communities grade from As a result of unsuccessful control tech- boundaries of the infestation are also subtropical rainforests and tall open for- niques the Broom Council was formed in treated biennially. These boundaries ests in the valleys through to cool temper- 1987. The council recognized that the dis- are either road edges or natural ate rainforests and subalpine woodlands tribution and ecology of broom did not al- boundaries such as rainforest. Recently and wetlands on the plateau (the latter low for its total eradication (Howard broom control has commenced in areas two are impacted by broom). Rainforests 1995). In 1987 a containment strategy was identified as containing threatened of Barrington Tops National Park are the developed between affected landholders, plant species. southern limit of World Heritage listed including New South Wales National 2. Identify and treat any isolated infes- rainforests of eastern Australia. The di- Parks and Wildlife Service (NPWS), State tations outside the main infestation. verse vegetation communities found Forests of New South Wales (SF NSW) Isolated infestations are identified by a in the park provide habitat for over 60 and private landholders. The aim of the biennial aerial survey and subse- rare or threatened plant and animal spe- strategy was to protect non-infested quently treated. Previously treated in- cies. subalpine and lower catchment areas and festations are mapped and monitored Broom infests an estimated 10 000 minimize broom spread from the main in- biennially. hectares of the Barrington Tops and is festation. In addition the NPWS has a re- 3. A monitoring program. Aims to: having a major impact on the natural ecol- sponsibility to contain broom in a way (a) identify isolated infestations, ogy of the subalpine environment (Water- that minimizes further environmental im- (b) measure changes in the density and house 1988, Smith 1994). This weed is pacts. distribution of the main infestation, 170 Plant Protection Quarterly Vol.15(4) 2000 (c) measure success of the annual con- The cut and paint technique minimizes Current treatment techniques have tainment program, soil disturbance reducing potential broom limitations and the cost of physical re- (d) monitor impact and spread of bio- seed germination. Physical removal re- moval and chemical application on such a logical control agents. duces impact to non-target species and grand scale (even for containment only) is 4. Co-ordination of management with protects water quality and aquatic fauna. high. Table 1 shows the cost of broom and adjoining landholders. As part of the containment strategy within associated control measures since 1985. 5. Provide community information and the main infestation herbicide spraying Considering the seed longevity and the awareness. using triclopyr is undertaken along verges quantity of soil stored seed (Hosking et al. 6. Support the biological control pro- of vehicle trails and walking trails. Treat- 1998) containment alone must continue to gram. Participate in the release of bio- ment extends 10–20 m from the road edge. protect subalpine areas outside the main logical control agents and implement Treatment of trails reduces seed spread to infestation and sensitive communities suitable monitoring programs. other areas by vehicles, walkers and ani- within the main infestation. This contain- 7. Identify the resources required to im- mals. Some of the treated areas along trail ment program also involves control of ver- plement the management strategy an- edges have become refuges for native tebrate pests. Dense broom thickets pro- nually. An annual works program has plant species including rare and threat- vide shelter for feral animals (Parsons and been developed for objectives 1 and 2. ened plants. Triclopyr is used, as it is not Cuthbertson 1992) such as pigs and foxes. This provides a detailed account of the detrimental to Poa sieberiana Spreng. var. The annual pig control program reduces location of treatment areas and appro- sieberiana which is the dominant ground- soil disturbance and potential movement priate control techniques. cover, thus protecting the soil from distur- of broom seed by pigs. bance. Other non-target species, particu- Biological control of broom is integral Control techniques larly rare plants can be at risk from herbi- to the longer-term containment program. Three control techniques are used during cides if applied indiscriminately (Heinrich Three biological control agents have been the annual program from October to Janu- and Dowling 1998, 2000). Staff and con- released in locations throughout the ary these include: tractors are being trained to identify rec- Barrington Tops plateau, Leucoptera 1. physical removal of immature broom, ognizable rare plant populations and less spartifoliella (Hübner) (twig mining moth), 2. cut and paint technique (stems are cut obvious ones are tagged to avoid herbi- Artainilla spartiophila (Förster) (a broom and neat glyphosate is applied), cide application to broom plants within psyllid) and Bruchidius villosus Fabricius 3. herbicide spraying. the vicinity. These broom plants are re- (seed feeding bruchid). Release sites have High costs are associated with physical moved either physically or by using the been recorded and impact and spread of removal and the cut and paint technique cut and paint technique. agents from these sites is being monitored. because they are labour intensive. There- The herbicide, triclopyr, is sprayed Once numbers build up a planned and fore these techniques are only employed from vehicle mounted rigs but is not used systematic approach to their redistribu- on isolated plants, small infestations or in near waterways, or in wetlands, in the tion is anticipated. the following areas: area because of potential impact to aquatic (a) where some populations of threatened ecosystems. All staff and contractors are Monitoring of the broom infestation plants are located, trained in appropriate use of herbicides to Previous ad hoc monitoring of the broom (b)along the edge of water ways and in decrease potential ecological impacts from infestation has indicated the need for a co- the subalpine wetlands, herbicide use. ordinated and consistent approach in the (c) in and around recreational areas.

Table 1. Expenses associated with broom control in Barrington Tops National Park from 1985 to 1999. Program 1985/ 1986/ 1987/ 1988/ 1989/ 1990/ 1991/ 1992/ 1993/ 1994/ 1995/ 1996/ 1997/ 1998/ 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996A 1997 1998 1999 NPWS labour / administration 15 000 15 000 18 000 20 000 22 000 25 000 20 000 15 000 15 000 5 000 5 000 4 000 4 000 5 000 Broom spraying (temporary labour) 2 500 3 500 4 000 5 000 5 000 3 000 Broom spraying (contract labour) 6 000 8 000 25 000 30 000 35 000 Broom physical removal 6 000 10 000 20 000 Herbicide and materials 7 000 11 500 13 000 16 000 10 000 6 000 4 500 5 500 4 000 4 500 5 000 12 000 12 000 10 000 Pig control staff and materials 3 000 3 000 4 000 4 000 4 000 4 000 5 000 4 000 4 000 5 000 7 000 10 000 7 000 7 000 Biological control program 25 000 25 000 27 000 33 000 33 000 27 000 27 000 25 000 20 000 Rare and threatened plant survey 30 000 Aerial survey (by helicopter) 2 000 2 000 Mapping of main infestation 20 000 Total 27 500 33 000 39 000 45 000 41 000 63 000 54 500 51 500 56 000 53 500 52 000 86 000 118 000 119 000 A In 1996 the Barrington Tops National Park received new additions which included 1000 hectares of crown land infested with broom. As a result of this new land resources were increased to support the Scotch Broom Management Strategy. Plant Protection Quarterly Vol.15(4) 2000 171 future. The two main infestations were Many of these species utilize the sub al- within the wetlands and along the edges first mapped by NPWS in 1988 from 1982 pine woodlands and wetlands. of rivers (M. Newton personal communi- aerial photographs. In 1989 SF NSW pro- Fauna species listed on the Threatened cation). Wetlands of high ecological duced maps showing the density (i.e. infill Species Conservation Act 1995 and known significance are being prioritized for within the infestations) from 1987 aerial to occur within Barrington Tops National physical broom removal. photographs. In 1992/3 SF NSW mapped Park and likely to occur on the plateau are: Since the 1970s fire on the plateau has the perimeter of the broom infestations. been largely restricted. Prior to this time, This map indicated a slight increase in the Birds low intensity summer burns associated area of the main infestations from 1987. Powerful owl with cattle grazing were common (NPWS Broom densities have only been recorded Ninox strenua (Gould) 1989). Broom infestation has resulted in on one occasion, therefore density Masked owl increased soil moisture levels (Water- changes within the main infestation are Tyto novaehollandiae (Stephens) house 1988) and a lack of ground cover. currently unknown. Additional aerial sur- Sooty owl There are now very few days where con- veys of the boundary of the broom infesta- Tyto tenebricosa (Gould) ditions are dry enough to carry fire result- tion were undertaken in 1996 and 1998 Rufous scrub-bird ing in a decline in fire events. Further re- with particular emphasis on locating iso- Atrichornis rufescens (Ramsay) search is required to gain an understand- lated infestations for on-ground treat- Painted snipe ing of fire ecology on the Barrington Tops ment. Aerial photographic runs were Rostratula benghalensis (Linnaeus) plateau and potential changes to fire ecol- completed in December 1998. Aerial pho- Glossy black-cockatoo ogy due to broom infestations. tographic interpretation (API) has re- Calyptorhynchus lathami (Temminck) cently been undertaken and will provide Olive whistler Research information regarding the rate of spread Pachycephala olivacea Vigors & There have been various research projects and densities. This information will be Horsfield undertaken on broom on the Barrington compared with the 1989 maps. Tops. More information, however, is re- Mammals quired to improve overall management of Threatened species and other Spotted-tailed quoll the broom infestations particularly in ref- environmental impacts Dasyurus maculatus (Kerr) erence to the ecology of species native to Broom is causing major ecological Parma wallaby the Barrington Tops plateau. The authors changes to the natural environment of the Macropus parma Waterhouse consider further research would be valu- Barrington Tops plateau (Waterhouse Broad-toothed rat able on: 1988, Smith 1994). The subalpine natural Mastacomys fuscus Thomas (a) impact of broom on threatened species, environment of Barrington Tops National Brush-tailed phascogale (b)impact of broom on the fire ecology of Park provides habitat for a range of threat- Phascogale tapoatata (F.A.Meyer) the Barrington Tops plateau, ened species. In 1997 the NPWS employed Koala (c) relationship between broom and intro- consultants to undertake a rare plant sur- Phascolarctos cinerus (Goldfuss) duced vertebrate pests, vey of the plateau area (Heinrich and Eastern freetail-bat (d)changes in broom density within the Dowling 1998). Although the survey had Mormopterus norfolkensis (J.E.Gray) main infestation, limitations it was designed to identify the Eastern false Pipistrelle (e) changes to the soil profile in areas of location, abundance and provide further Falsistrellus tasmaniensis (Gould) infestation, information on rare or threatened plants Common bent-winged bat (f) impact of broom on subalpine wet- likely to occur within the broom infesta- Miniopterus schreibersii (Kuhl) lands, waterways and open plains. tions. The information gained has been in- Little bentwing bat valuable in assisting with the protection of Miniopterus australis (Tomes) Future broom management those species. Distribution records from Yellow-bellied sheathtail-bat Broom containment forms just part of the the survey are being used to assist in tar- Saccolaimus flaviventris (Peters) annual operational management of geting broom control. Greater broad-nosed bat Barrington Tops National Park, which In total, 28 species of rare or threatened Scoteanax rueppellii (Peters) also includes management of feral ani- plants have been identified within the mals, fire, recreational use as well as natu- main broom infestations of the Barrington Amphibians ral and cultural resources. Part of the Tops plateau (Heinrich and Dowling Glandular frog success of the broom containment pro- 1998). Of these, four are listed as vulner- Litoria subglandulosa Tylers & Anstis gram has been due to ongoing communi- able under the New South Wales Threat- Stuttering frog cation with surrounding landholders ened Species Act 1995 and seventeen (in- Mixophyes balbus Straughan to ensure a coordinated program. The cluding the four vulnerable species) are NPWS is committed to a regional/catch- listed as rare or poorly known in Briggs In the case of the broad-toothed rat, broom ment approach to pest management (Leys and Leigh (1996). Five possible new spe- is invading the edges of the subalpine 1998). cies of orchids were also discovered in the wetlands, outcompeting grasses such as P. As land managers the NPWS have a re- 1998 survey (Heinrich and Dowling 1998). sieberiana var. sieberiana which are an im- sponsibility to continue to implement con- The study highlighted the importance of portant shelter and food source for the rat. tainment programs that will not compro- the Barrington Tops plateau for rare, Further research on the plateau is required mise existing natural ecosystems. NPWS threatened and endemic plant species and to determine the distribution of threat- will continue environmental assessment indicated the need for further survey ened fauna species and the potential im- of control techniques. The broom infesta- work to be undertaken. For more informa- pact of broom upon them. tion is likely to expand unless the contain- tion on rare and threatened plant species The wetlands within the subalpine area ment program is successful. The success of of the Barrington Tops see Heinrich and feed six river systems. Use of herbicides this program is reviewed annually. Dowling (2000). for broom control within wetlands and The program will continue to prevent Twenty seven species of threatened along waterways is unacceptable because infestation of unaffected catchments and fauna (NPWS Wildlife Atlas 1999) occur of potential impacts on aquatic flora and subalpine environments. NPWS also aims within Barrington Tops National Park. fauna. Broom is becoming more common to protect sensitive communities within 172 Plant Protection Quarterly Vol.15(4) 2000 the main infestation by using an inte- Strategy to include new areas of the Na- ssp. scoparius. In ‘The biology of Aus- grated management strategy. In addition tional Park. tralian weeds’ Volume 2, eds F.D. to the containment program, effective Panetta, R.H. Groves and R.C.H. monitoring and continued research are an References Shepherd, pp. 77-88. (R.G. and F.J. integral component of managing broom in Adams, B. (2000). Raising awareness of Richardson, Melbourne). the future. The use of biological control the broom (Cytisus scoparius (L.) Link) Howard, C. (1995). Hunter District Sub- agents is regarded as the only economic problem on the Barrington Tops. Pro- mission to the Wilderness Assessment long-term method of reducing the size of ceedings of the broom symposium held Report for Barrington Tops. Unpub- the main broom infestations. A planned at Ellerston and Moonan, 16–17 No- lished report. systematic redistribution program for bio- vember 1998, eds A.W. Sheppard and Leys, A. (1998). NSW National Parks and logical control agents will be undertaken J.R. Hosking. Plant Protection Quarterly Wildlife Service Summary of Pest Man- in collaboration with researchers once 15, 139-40. agement Programs 1997/98. Unpub- numbers of agents build up. Briggs, J.D. and Leigh, J.H. (1996). ‘Rare or lished. threatened Australian plants’. (CSIRO NPWS (1989). Draft plan of management Acknowledgments Publishing, Melbourne). of Barrington Tops National Park, New We would like to thank M. Newton, Sen- Heinrich, A. and Dowling, B. (1998). Rare South Wales National Parks and Wild- ior Field Supervisor, NPWS, for informa- and threatened plant survey of life Service, Raymond Terrace office of tion on broom control on the Barrington Barrington Tops National Park - pla- NPWS. Tops. He has been involved with broom teau area. Unpublished report pre- NPWS (1999). The NSW National Parks control in Barrington Tops National Park pared for the NSW National Parks and and Wildlife Atlas database, CD ROM. since the 1970s. Wildlife Service. Parsons, W.T. and Cuthbertson, E.G. Heinrich, A. and Dowling, B. (2000). (1992). ‘Noxious weeds of Australia’. Postscript Threats to the rare and threatened plant (Inkata Press, Melbourne and Sydney). In March 1999 the Barrington Tops Na- species of the Barrington Tops. Pro- Smith, J.M.B. (1994). The changing eco- tional Park was expanded to include areas ceedings of the broom symposium held logical impact of broom (Cytisus scopar- of Barrington Tops State Forest and at Ellerston and Moonan, 16–17 No- ius) at Barrington Tops, New South Polblue Crown Land Reserve. The NPWS vember 1998, eds A.W. Sheppard and Wales. Plant Protection Quarterly 9, 6-11. are now responsible for management of J.R. Hosking. Plant Protection Quarterly Waterhouse, B.M. (1988). Broom (Cytisus most of the broom infestations occurring 15, 172-6. scoparius) at Barrington Tops, New on community lands. The NPWS is cur- Hosking, J.R., Smith, J.M.B. and Sheppard, South Wales. Australian Geographical rently reviewing the 1996 Management A.W. (1998). Cytisus scoparius (L.) Link Studies 26, 239-48.

extensive areas of almost treeless, wet Threats to the rare and threatened plant species of heath and sedgelands occurring in drain- age depressions of both Barrington and Barrington Tops Gloucester Tops. These areas are often very open and therefore exposed to dry- Anne HeinrichA and Bill DowlingB ing winds, ice and snow. Some wetlands A 389 Playfords Road, Comboyne, New South Wales 2429, Australia. were more protected from the extreme weather conditions as they occur between B PO Box 197, Dungog, New South Wales 2420, Australia. wooded areas e.g. Little Murray wetland. Mean annual rainfall over Barrington Tops and Gloucester Tops is approxi- Summary mately 1470–1700 mm (CMPS&F Environ- Future management of rare and threat- State Forests and private land should mental 1995). Some areas on the escarp- ened plant species in the Barrington place high priority on the protection of ment side receive higher rainfall than ar- Tops National Park on the Barrington the whole subalpine habitat as well as eas further north-west, away from the es- and Gloucester Tops plateau is depend- populations of rare plants by focusing carpment (CMPS&F Environmental 1995). ent upon knowledge of their locations, funding priorities to reduce these Mean annual temperature is about 9°C abundance and threats to their survival. threats. (Tweedie 1963). A literature and field survey was carried According to Veness and Associates out in summer 1997–98 and further field Introduction (1995) the two parent rock types on the surveys in summer 1998–99 and spring The plateau in the Barrington Tops Na- plateau area are granodiorite and tertiary 1999. Surveys found that 30 species of tional Park covers an area of 11 000 ha and basalt. Resulting soils are friable with scat- rare or threatened plants, 18 of which are is dominated by subalpine woodland tered stones. Granodiorite soils consist of possibly endemic, are likely to occur, or where the major tree species is Eucalyptus a dark reddish brown, silty clay loam A are known to occur, on the plateau area pauciflora Sieber ex Spreng. interspersed horizon while basalt topsoils are charac- of Barrington Tops and Gloucester Tops. with Eucalyptus stellulata Sieber ex DC., terized by strong pedal layers of a very Nine possible new species, all Orchid- Eucalyptus dalrympleana Maiden and Euca- reddish brown, subplastic, silty clay loam. aceae, were located during the literature lyptus fastigata H.Deane & Maiden. In ad- The A2 horizon in basalt areas consists of and field surveys. Populations of rare dition the plateau has an extensive system a dark reddish brown, silty clay or is and threatened plants were found both of subalpine wetlands and patches of cool unbleached (Veness and Associates 1995). in the National Park and in forestry land. temperate rainforest dominated by Much of the 11 000 hectares in the Na- Threats include further spread of broom Nothofagus moorei (F.Muell.) Krasser up to tional Park and extensive areas outside the (Cytisus scoparius), spread of other 1550 m above sea level (asl). Park are affected to varying degrees by weeds, feral pigs, recreational use and A considerable part of the plateau is broom (Cytisus scoparius (L.) Link subsp. fire. Managers of the National Park, occupied by subalpine wetlands which are scoparius) which has the potential to