Our place. People, priorities and practice in weed management

14TH QUEENSLAND WEED SYMPOSIUM

4-7 DECEMBER 2017, PORT DOUGLAS, QUEENSLAND

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USB SPONSOR A Threat to the Wet Tropics MICONIA (PHOTO: DAF AND AND DAF (PHOTO: MICONIA QPWS) ~ ROACH CHRIS Weeds Wet Tropics: An Exceptional Ecosystem Current Programmes The Wet Tropics region houses Australia’s greatest diversity The Wet Tropics Management Authority collaborates with of distinctive and irreplaceable plants and animals within community, governments and landholders on monitoring just 0.26% of the continent: and eradication programmes for tropical weeds such as: limnocharis, mikania vine and three miconia species. ~ 65% of Australia’s fern species However vigilance is key, as many ‘sleeper’ weeds exist ~ 60% of Australia’s butterfly species now in the Wet Tropics, with the potential to proliferate ~ 40% of Australia’s bird species under the right conditions. ~ 42% of Australia’s freshwater fish ~ 30% of Australia’s mammal species ~ 30% of Australia’s orchid species The region’s close links to its neighbours and ideal growing climate makes it particularly vulnerable to invasive plants.

MICONIA RACEMOSA FRUIT LIMNOCHARIS PLANTS, FLOWER AND MICONIA FLOWERS (PHOTO: DAF) (PHOTO: TRAVIS SYDES) SEED PODS (PHOTOS: DAF)

The Wet Tropics Management Authority is committed to community education, awareness and participation as vital tools to prevent the introduction and spread of invasive species into the Wet Tropics.

| wettropics.gov.au th The Authority is proud to support the 14 Queensland Weed Symposium as part of its ongoing work | [email protected] to protect biodiversity in the Wet Tropics from invasive pests. | 07 4241 0500

CONTENTS

Session one: biological control – research investment AT LAST, BIOLOGICAL CONTROL OF BELLYACHE BUSH ...... 4 Dianne B. J. Taylor, Elizabeth L. Snow, Kerri Moore and Kunjithapatham Dhileepan ...... 4 UPDATE ON BIOLOGICAL CONTROL AGENT, ACERIA LANTANAE (LANTANA BUD MITE) ON LANTANA CAMARA IN NORTHERN QUEENSLAND ...... 10 Kelli Pukallus1, Michael Day2, Natasha Riding2, Judy Clark1 ...... 10 IMPLEMENTATION OF THE LAND PROTECTION FUND CO-INVESTMENT MODEL ... 16 Kristy Gooding ...... 16 Session two: eradication – two steps forward one step back ERADICATION OF RED WITCHWEED – ONE STEP AT A TIME! ...... 21 Peter J. Austin1, Daniel C. Stampa1 and Joseph S. Vitelli2 ...... 21 SIAM WEED (CHROMOLAENA ODORATA) THE RECENT PAST AND OPTIONS FOR THE FUTURE ...... 27 David Green ...... 27 KOSTERS’ CURSE – A MULTI-AGENCY APPROACH TO MANAGEMENT ...... 32 Kelly Ashwood1, Damon Sydes1 ...... 32 ADVANCING PRICKLY ACACIA MANAGEMENT THROUGH THE WAR ON WESTERN WEEDS INITIATIVE...... 39 Nathan March1, Wayne Vogler2 and Kunjithapatham Dhileepan 3 ...... 39 UNDERSTANDING AND IMPROVING THE BEST MANAGEMENT PRACTICE OF MEXICAN BEAN TREE IN THE WILDERNESS OF TROPICAL NORTH QUEENSLAND...... 44 Michael Graham ...... 44 Session three: protecting values CONSERVING BLACK-THROATED FINCH HABITAT ...... 50 Jaymie Rains ...... 50 LANTANA CONTROL ON EASTERN TORRES STRAIT ISLANDS USING SPLATTER GUN TECHNIQUE...... 56 Janine Buist2, John Lynn1, Aaron Bon1 and Boggo Gela1 ...... 56 BRIDGING BARRIERS THROUGH PARTNERSHIPS FOR WEED MANAGEMENT ON CAPE YORK ...... 61

1 Peta-Marie Standley1, Vicki Wundersitz1, Wunthulpu Aboriginal Land Trust...... 61

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Session four: biocontrol part two BROAD SCALE INTRODUCTION OF CROWN ROT IN WEEDY SPOROBOLUS GRASSES (GIANT RAT’S TAIL AND GIANT PARRAMATTA GRASS) ...... 66 Jeremy Bradley and Cathy Eggert ...... 66 BIOLOGICAL CONTROL OF PARTHENIUM: PROGRESS ON THE REDISTRIBUTION OF ESTABLISHED AGENTS TO SOUTHERN QUEENSLAND ...... 72 J.T. Callander1, B. Shi1, S. Raghu2 and K. Dhileepan1 ...... 72 BIOLOGICAL CONTROL: NOT AS SIMPLE AS IT SEEMS ...... 77 Elizabeth Snow, Michael Day ...... 77 Session five: invasive grasses TO BURN OR NOT TO BURN: USING FIRE TO MANAGE A COMPLEX GRASS ECOSYSTEM ...... 82 Wayne Vogler ...... 82 MANAGING BUFFEL GRASS TO PROMOTE SPECIES RICHNESS AND FACILITATE ECOSYSTEM RECOVERY ...... 88 Melzer R.1 and Melzer A.2 ...... 88 GIANT RAT’S TAIL GRASS: LESSONS LEARNT FROM CONTROL TRIALS AND LANDHOLDER ENGAGEMENT IN THE MACKAY WHITSUNDAY REGION ...... 94 Emily Wood ...... 94 THE POTENTIAL FOR FERTILISER TO CONTROL WEEDY SPOROBOLOUS SPP. IN CENTRAL QUEENSLAND: RESULTS FROM BYFIELD...... 98 John Reeve1, Stuart Buck2 and Leisa Childs3 ...... 98 Session six: surveillance tools and approaches TESTING THE UTILITY OF NOVEL, PRE-EMPTIVE SURVEILLANCE TECHNIQUES TO ACHIEVE EARLIER DETECTION OF FIVE HIGH-RISK WEEDS...... 104 Steve Csurhes, Duncan Swan, Matt Ryan and Lyn Willsher ...... 104 UAV’s – A SNAZZY TOY OR A REAL SOLUTION FOR AERIAL WEED SURVEILLANCE ...... 109 Jochem van der Reijden ...... 109 BITOU BUSH SURVEILLANCE UAV TRIAL ...... 113 Stacy Harris¹, Peter Trotter²...... 113 WHAT CAN I DO WITH WEED CONTROL DATA? ...... 119 Brooks1, S.J...... 119 SOME RAPIDLY EMERGING WOODY WEEDS IN SOUTH-EASTERN QUEENSLAND

...... 126 2

Sheldon Navie ...... 126 Page

Session seven: informed decisions SURVIVAL AND BUOYANCY OF HYGROPHILA COSTATA STEM FRAGMENTS IN SALT, BRACKISH AND FRESH WATER...... 132 Setter, M.J.1, Setter, S.D. 1 and Styman, D.T.2 ...... 132 IMPLEMENTING PEST PLANNING ON THE GROUND: KEEPING THE PIGS OUT OF THE CHOCOLATE PUDDING...... 138 Geoff Lundie-Jenkins and John Hodgon ...... 138 GOOD NEIGHBOUR PROGRAM (GNP) – MANAGING PESTS IN THE FLINDERS SHIRE ...... 143 Robyn Young ...... 143 SUCCESSFUL COMMUNITY ENGAGEMENT FOR WEED CONTROL ON PRIVATE LAND. CONSERVATION PARTNERSHIPS – CITY OF GOLD COAST ...... 147 Lexie Webster, Todd Burrows and Donald Mackenzie ...... 147 Posters presentations: SIAM WEED DISPERSAL MECHANSIMS ...... 153 Brooks1, S.J., Setter2, S.D. and Gough1, K.L...... 153 EXTENDING FLUPROPANATE USE – SPOT APPLICATION ON PERENNIAL MISSION AND GAMBA GRASS ...... 159 Wayne Vogler1, Emma Carlos1 and Kelsey Hosking1 ...... 159 FROM PRICKLY ACACIA TO PASTURE – KEY LESSONS FROM A MECHANICAL CONTROL FIELD STUDY ...... 164 Nathan March1 and Samantha Cullen2 ...... 164

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AT LAST, BIOLOGICAL CONTROL OF BELLYACHE BUSH

Dianne B. J. Taylor, Elizabeth L. Snow, Kerri Moore and Kunjithapatham Dhileepan Biosecurity Queensland, Department of Agriculture and Fisheries, Ecosciences Precinct, Boggo Road, Dutton Park, Queensland 4102, Australia.

ABSTRACT

Jatropha gossypiifolia, commonly known as bellyache bush, is a serious weed of rangelands and riparian zones of northern Australia. Since bellyache bush became a target for biological control in 1997, only one agent has been released and this failed to establish. A renewed biological control effort has identified a number of potential agents. A small leaf-mining moth, Stomphastis sp. (Lepidoptera: Gracillariidae), was imported from Peru into quarantine for further research in 2014. Newly emerged larvae mine directly into a leaf and remain there until pupation. No-choice host specificity testing of Stomphastis sp. has been completed for 43 test plant species. The moth laid eggs on numerous non- target species; however development of the agent only occurred on bellyache bush and its congener J. curcas, which is also a weed. Quarantine testing has thus confirmed that the leaf miner is highly host specific and suitable for release in Australia. An application to release this agent will be submitted to the Australian government in the near future. A second agent, Sciota divisella (Lepidoptera: Pyralidae) from India, was imported into quarantine in 2015. The larvae of this moth feed on the leaves, stems and fruit of bellyache bush. No-choice host specificity testing of this agent is in progress. To date, complete development has occurred on five exotic species and two natives. The potential use of the two native species as hosts is being investigated further. Other prospective agents under consideration include a gall midge from Bolivia and a leaf-feeding midge from Paraguay.

Keywords: Jatropha gossypiifolia, Stomphastis, Sciota, Australia

INTRODUCTION

Jatropha gossypiifolia L. (Euphorbiaceae), commonly known as bellyache bush, is a serious weed of rangelands and riparian zones of northern Australia, and it has the potential to invade much of northern Australia (Heard et al. 2012). It forms dense thickets, reducing the usefulness of land for pastoral and grazing purposes. Monotypic stands supress seedling recruitment of native species, reducing biodiversity and impacting fire regimes due to reduced fuel load. The shallow root system causes increased erosion along creek and river banks (Bebawi et al. 2007). All parts of the plants are toxic to stock and humans. Biological control is an important component of the long-term management strategy for J. gossypiifolia in Australia. Biological control of bellyache bush was initiated in 1999. Since then, only one agent, the jewel bug, Agonosoma trilineatum (F.) has been released and there is no evidence of its establishment (Heard et al. 2012).

A renewed biological control effort, involving exploration in South America, identified a 4 number of potential biological control agents (Dhileepan et al. 2014). The most promising was a small leaf-mining moth Stomphastis sp. (Lepidoptera: Gracillariidae) which was imported from Peru into quarantine in 2014 for further research. A second agent, Sciota Page

divisella (Duponchel) (Lepidoptera: Pyralidae), was found on bellyache bush during opportunistic surveys conducted in India and was imported into quarantine in 2015. The larvae of this moth feed on the leaves, stems and fruit of bellyache bush. In this paper, we discuss the progress of quarantine testing for both of these species and future actions.

MATERIALS AND METHODS

Stomphastis sp.

Stomphastis sp. was imported into our quarantine facility in Brisbane in November 2014 (Taylor et al. 2016). Adult Stomphastis sp. are small moths (less than 1 cm long) and live for an average of 10 days under quarantine conditions. Females lay eggs singly on leaves. Newly emerged larvae mine directly into the leaf and remain in the leaf as they develop. Larvae exit the leaf to pupate, mainly on the leaf. A generation from adult to adult takes around 22 days under quarantine conditions (Taylor et al. 2016).

The host test list for Stomphastis sp. contains 43 species from the Euphorbiaceae and closely related families; 33 are native species and 10 are exotic species (Table 1). All test plants were subjected to no-choice oviposition/larval development trials, with at least five replicates conducted for most species. Twenty newly emerged, unsexed Stomphastis sp. adults were released into a 45 x 45 x 90 cm gauze covered cage, containing a single potted test plant. With each round of testing, at least one bellyache bush plant was also included as a control, however only ten newly emerged adults were released into this cage. Test plants were maintained until a new generation of adults were recovered from bellyache bush, at which time they are disposed of. Test species on which Stomphastis sp. completed development, were subject to choice oviposition/larval development trials with bellyache bush.

Sciota divisella

In India, S. divisella was observed feeding on bellyache bush, J. curcas and Euphorbia grantii Oliv., (Snow et al. 2016). A colony was established in quarantine in July 2015, with a further importation in October 2015 to augment the colony. Female S. divisella lay eggs in clumps or rows on leaves and the upper portions of stems of bellyache bush plants (Snow et al. 2016).

Native, crop and ornamental species from the Euphorbiaceae and closely-related families were included in the host testing. Initially test plants were subject to no-choice larval development trials, with at least five replicates for each species. Ten newly-hatched S. divisella larvae were carefully placed onto each potted test plant which were each enclosed in a 45 x 45 x 90 cm gauze covered cage. With each round of testing, at least one bellyache bush plant was also included as a control. Test plants were maintained until a new generation of adults were recovered from bellyache bush, at which time they are disposed of. Native species on which complete development occurred will be subject to further testing including oviposition and choice trials.

RESULTS

Stomphastis sp. 5 Under no-choice conditions, Stomphastis sp. females laid eggs on 29 of the 43 test species, predominantly on leaves at the top of the plants. Egg hatch occurred on 24 of Page

these species. However, in all cases except on bellyache bush and J. curcas, the 1st instar larvae died shortly after emerging (Figures 1 and 2). When female Stomphastis sp. were provided with both bellyache bush and J. curcas, they oviposited at an equal rate on both species. The proportion of eggs that developed into adults was also similar for the two species.

Sciota divisella

To date larval development trials have been completed for 13 test species and partially completed for further 22 species (Table 1). These include 25 native and ten exotic species. Complete larval development has occurred on seven non-target species – five exotic species (J.curcas, J. podagrica Hook., Manihot esculenta Crantz., Euphorbia nerifolia L. and E. grantii) and two native species (Macaranga tannarius (L.) Müll.Arg. and E. plumerioides Teijsm. ex Hassk.) (Figure 3). In no-choice oviposition trials females have laid eggs on M. tannarius. Euphorbia plumerioides is yet to be tested.

DISCUSSION

No-choice tests are rigorous tests and identify the absolute host range; insects either feed/lay eggs on the test plant or die. Host specificity test results for Stomphastis sp. provide strong evidence that it is highly host specific and suitable for release in Australia. The non-target species on which eggs were laid have been shown to be unsuitable hosts by the absence of any larval development. Larval development only occurred on bellyache bush and J. curcas. Though not declared as a weed in Queensland, J. curcas is regarded as invasive and is an approved target for biological control in Australia. Utilisation of this species in the field by Stomphastis sp. would thus be beneficial. Jatropha curcas was the only congener of three tested to support any development of the insect past the first instar.

Biological studies conducted in quarantine demonstrated that Stomphastis sp. has both a short generation time and high fecundity. This bodes well for its future as a biological control agent. It is expected that like other Gracillaridae, Stomphastis sp. will be an adept disperser, a desirable characteristic given the expansive areas across which bellyache bush occurs. A release application will be submitted to the relevant regulatory bodies later this year. If approved for release, the release effort for Stomphastis sp. will be focussed in areas with major bellyache bush infestations, such as along the Burdekin River from Charters Towers to Home Hill, Hughenden and Gulf of Carpentaria, along the Gregory River and Normanton, and along the Palmer River in Cape York. Given the ease with which the insect can be reared, there will be an opportunity to explore partnerships with various community and NRM groups. Insects will also be supplied to stakeholders in the Northern Territory and Western Australia (in partnership with the respective government bodies).

The second bellyache bush insect currently in our quarantine facility, S. divisella, is a highly damaging insect. However, due to the development of the insect on two native species (M. tannarius and E. plumerioides) and cassava (M. esculenta) during host testing, the insect is unlikely to be pursued for release. Testing of S. divisella is continuing on species partially tested (where feeding has occurred), as well as oviposition tests with

M. tannarius and E. plumerioides to elucidate results from larval development trials. Other 6 prospective insects under consideration for bellyache bush include a gall midge from Bolivia (Prodiplosis longifila Gagné) and a leaf-feeding midge from Paraguay (Prodiplosis Page

sp. near longifila) (Dhileepan et al. 2014). The gall midge induces galls in shoot-tips, emerging leaves and stems of bellyache bush. Preliminary testing of the gall midge is in progress in South America and South Africa. If results are favourable, the gall midge will be imported into quarantine for further testing and research. Host specificity testing and field trials with the Jatropha rust, Phakopsora arthuriana, have been completed and indicate that it is highly host specific. Studies are currently in progress to determine if the rust is autoecious or heteroecious (completes its lifecycle on a single species or requires a second unrelated host).

ACKNOWLEDGEMENTS

This project was funded by Meat and Livestock Australia and the Queensland Government’s War on Western Weeds funding initiative. We thank Dr Stefan Neser (Plant Protection Research Institute, South Africa), Dr Marion Seier, Kate Pollard (CABI-UK), Victor Hugo Sanchez (Instituto National de Investigacion Agraria, Tarapoto, Peru), Dr A. Balu and S. Murugesan (Institute of Forest Genetics and Tree Breeding, India), Dr Damian Rumiz (Santa Cruz, Bolivia) for their help with the overseas field studies, Dr Jurate De Prins (Royal Belgian Institute of Natural Sciences, Belgium) for her help with the identification and description of the leaf miner, David Fredericks for technical support and Dr Marianne Horak (CSIRO, Canberra) and Dr David Lees (Natural History Museum, UK) for their help with identifying the leaf webber. Thanks to Tony Pople for comments on this manuscript.

REFERENCES

Bebawi, F.F., Vitelli, J.S., Campbell, S.D., Vogler,W.D., Lockett, C.J., Grace, B.S., Lukitsch, B. and Heard, T.A. 2007. The biology of Australian weeds 47. Jatropha gossypiifolia L. Plant Protection Quarterly 22, 42-58.

Dhileepan, K., Neser, S. and J. De Prins. 2014. Biological control of bellyache bush (Jatropha gossypiifolia) in Australia: South America as a possible source of natural enemies, pp. 5-10. In: Impson, F.A.C., Kleinjan, C.A., and Hoffmann, J.H. (eds), Proceedings of the XIV International Symposium on Biological Control of Weed, Kruger National Park, South Africa, 2-7 March 2014.

Heard, T.A., Dhileepan, K., Bebawi, F., Bell, K. and Segura, R. 2012. Jatropha gossypiifolia L. – bellyache bush. In ‘Biological control of weeds in Australia: 1960 to 2010’, eds M. Julien, R.E. McFadyen and J. Cullen, pp. 324-33. (CSIRO Publishing, Melbourne)

Snow, E. L., Dhileepan, K. and Taylor, D.B.J. 2016. The Jatropha webber (Sciota divisella): a potential biological control agent for Jatropha gossypiifolia (bellyache bush) from India. pp. 237-240. In: Randall, R., and Lloyd, S. Borger, C. (eds), Proceedings of the 20th Australasian Weeds Conference, Weeds Society of Western Australia, Perth, 11-15 September 2016.

Taylor, D.B.J. and Dhileepan, K. 2016. Prospects for the biological control of Jatropha

7 gossypiifolia: Stomphastis sp. as a potential agent from South America. pp. 233-237. In: Randall, R., and Lloyd, S. Borger, C. (eds), Proceedings of the 20th Australasian Weeds

Conference, Weeds Society of Western Australia, Perth, 11-15 September 2016. Page

Table 1. Host test list and replicates completed for no-choice tests. Test plants Status# Stomphastis sp. Sciota divisella Euphorbiaceae Crotonoideae Jatropha gossypiifolia L. Target 36 16 Jatropha curcas L. I 5 5 Jatropha multifida L. O 5 4 Jatropha podagrica Hook. O 5 3 Aleurites sp. N 5 3 Baloghia inophylla (G.Forst.) P.S.Green N 5 1 Beyeria lechenaultii (DC.) Baill. N 6 5 Beyeria viscosa (Labill.) Miq. N 5 5 Codiaeum variegatum (L.) A.Juss. E 5 1 Croton acronychioides F.Muell. N 7 5 Croton insularis Baill. N 5 3 Croton verreauxii Baill. N 5

Manihot esculentum Crantz C 6 3 Manihot grahamii Hook. I 6

Ricinocarpos pinifolius Desf. N 3

Acalyphoideae Acalypha capillipes Müll.Arg. N 5 5 Alchornea ilicifolia (J.Sm.) Muell.Arg. N 5

Endospermum sp. N 5 5 Macaranga tanarius (L.) Müll.Arg. N 5 5 Mallotus philippensis (Lam.) Muell.Arg. N 5 2 Omphalea celata P.I.Forst N 6 3 Ricinus communis L. I 5 1 Euphorbioideae Euphorbia grantii Oliv. E 5 5 Euphorbia inermis Mill. E 3

Euphorbia nerifolia L. E 5

Euphorbia plumerioides Hassk. N 3 4 Euphorbia pulcherrima Willd. ex Klotzsch E 5 3 Euphorbia tannensis Spreng N 5 2 Euphorbia tithymaloides L. E 5

Homalanthus populifolius Graham N 5 3 Microstachys chamaelea (L.) Hook.f. N 5

Phyllanthaceae Antidesma bunius (L.) Spreng. N 5 3 Antidesma ghaesembilla Gaertn. N 5

Actephila lindleyi (Steud.) Airy Shaw N 5 5 Breynia cernua (Poir.) Mull.Arg. N 5 5 Breynia oblongifolia (Mull.Arg.) Mull.Arg N 3 3 Bridelia exaltata F. Muell. N 6

Cleistanthus hylandii Airy Shaw N 6 2 Flueggea virosa (Willd.) Voigt N 5 2 Glochidion ferdinandi (Muell.Arg.) F.M.Bailey N 5 3 Phyllanthus cuscutiflorus S.Moore N 5

Picrodendraceae Austrobuxus swainii (Beuzev. & C.T.White) Airy Shaw N 5 5 Dissiliaria baloghioides F.Muell. ex Baill. N 5 5 Petalostigma pubescens Domin N 5 2 Sankowskya stipularis P.I.Forst. N 5

Putranjivaceae 8 Drypetes deplanchei (Brongn. & Gris) Merr. N 5 2 (#Status: N=native, O=ornamental, C=crop, I=invasive). Page

Figure 1. 1st instar larval mines of Stomphastis sp. on Croton verreauxii Baill. (left) and Baloghia inophylla (G.Forst.) P.S.Green (right).

Figure 2. Stomphastis sp. damage to bellyache bush (left) and J. curcas (right).

Figure 3. Sciota divisella feeding damage on bellyache bush (left) and on Euphorbia plumerioides (right).

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UPDATE ON BIOLOGICAL CONTROL AGENT, ACERIA LANTANAE (LANTANA BUD MITE) ON LANTANA CAMARA IN NORTHERN QUEENSLAND

Kelli Pukallus1, Michael Day2, Natasha Riding2, Judy Clark1 1 Department of Agriculture and Fisheries, Tropical Weeds Research Centre, Charters Towers, Queensland. 2 Department of Agriculture and Fisheries, Ecosciences Precinct, Dutton Park, Queensland.

ABSTRACT

Between 2014 and mid-2017, over 1300 lantana bud mite-filled galls were released at 70 sites in northern Queensland, encompassing the area from Mackay north to Cairns. Aceria lantanae has been detected at only four release sites at Charters Towers, Tully, Kuranda and Clare. Additionally A. lantanae has spread across hundreds of kilometres, with the furthest distance detected from a known release site being approximately 50 kilometres.

Keywords: Aceria lantanae, Lantana camara, lantana bud mite, biological control, northern Queensland.

LANTANA

Lantana camara has been regarded as one of Australia’s worst weeds and a target of biological control efforts since 1914. Thirty two biological control agents have been introduced for its control, with 19 of these confirmed established, including Aceria lantanae (lantana bud mite). Native to tropical and subtropical South America, L. camara forms dense thickets, threatens biodiversity, reduces productivity of pastures and forestry, and is toxic to stock. It prefers open sunny areas, but can be found in part-shade locations under canopies and is adapted to a wide variety of environmental and climatic conditions (Day et al. 2003). Flowering is triggered by rain events and warm, humid conditions, enabling lantana to flower almost all year round in northern Queensland. Twenty nine different weedy varieties of L. camara have been noted within Australia by Smith & Smith (1982) but this number could be more due to the trans-varietal nature and phenotypical variance in the flowers. These variations in flower colour, occur throughout seasons and a plant can simultaneously display more than one flower colour (Figure 1d.). Australian lantana are commonly sorted into five flower colour varieties: pink, pink-edged red, red, orange and white (Day 2012).

ACERIA LANTANAE

Aceria lantanae (Cook) (Acari: Trombidiformes: Eriophyidae), are microscopic (0.1-0.15 mm long) mites (Figure 1a.) native to tropical America and the Caribbean (Flechtmann and

Harley 1974). The lantana bud mite was approved as a biological control agent for L. 10 camara in Australia in 2012. The feeding activity of A. lantanae causes galling, a clustering of abnormally grown plant cells, primarily on the flower heads (Figure 1b.), thus Page

reducing seed production and subsequent spread of the plant. Galls can also form in vegetative plant material (Figure 1c.), causing distortion to leaves and shoot growth. Galls form 2-8 weeks after mite activity and can reach 45 mm in diameter. Formation occurs mainly in summer and autumn, associated with high humidity and active growth after rainfall events. Most mites are females, with the lifecycle completed within the developing gall, in less than 15 days under ideal conditions, (Sabelis and Bruin 1996, Riding et al. 2015).

Figure 1. a) Aceria lantanae (left); b) Flower head galls on lantana (middle left); c) Vegetative galls on lantana (middle right); d) Dual coloured pink/pink-edged red lantana (right).

RELEASES

Mass-rearing occurred at two Department of Agriculture and Fisheries (DAF) facilities: Ecosciences Precinct (Brisbane) and Tropical Weeds Research Centre (Charters Towers). Releases initially focused on red flower variants (pink-edged red, red and orange) due to preferences shown through host testing (Riding et al. 2015) and in areas where the Ecoclimatic Index (EI) values were greater than 51 as generated from the CLIMEX modelling software (Figure 3.). Over 1300 mite-filled galls have been released from 2014 to mid-2017 at 70 sites in northern Queensland, encompassing the area from Mackay north to Cairns (Figure 2.). This included the local government areas of Cassowary Coast, Charters Towers, Townsville, Burdekin, Mareeba, Tablelands, Hinchinbrook, Mackay and Whitsunday (Table 1). Releases were conducted by local government employees, Department of National Parks, Sports & Racing and DAF employees and landholders.

Table 1. Aceria lantanae galls released into local government areas in northern Queensland (2014 -2017) and number of established sites (including new detection sites).

Local Government Area # galls released # established sites

Burdekin 105 9 Cassowary Coast 235 0

11 Charters Towers 85 11 Hinchinbrook 53 1 Page

Mackay 191 0 Mareeba 213 1 Tablelands 226 0 Townsville 249 5 Whitsunday 20 0

Total 1377 27

Release sites consisted of roadside verges, gullies or creek systems, National Parks, State Forest, paddocks or power line corridors in full sun, shaded or partly shaded locations and at varying altitudes. These locations were expanded to include lower EI valued locations and include the pink flowering variety as the project progressed. Releases were conducted by placing mature galls or gall segments in active growing tips of lantana plants. Preference was given to actively growing plants in sunny locations and those about to develop flowers. Galls were sourced from rearing colonies or redistributed from field collections at established sites. Each site received galls, with repeated releases conducted in some cases.

ESTABLISHMENT

Establishment has been noted at only four release sites in northern Queensland “Barkla” (Charters Towers), “Woodhouse” (Burdekin), Cardstone Rd-Tully hydro station (Hinchinbrook) and Kuranda (Mareeba), with many sites still unchecked in the far north. All established release sites have had only one release of galls before establishment was noted, although the number of galls released varied: “Barkla” – 20 galls, “Woodhouse” – 20 galls, Cardstone Rd-Tully Hydro station – 3 galls, Kuranda - 4 galls. In the far north, detections have been on red or pink-edged red flowering varieties and in the lower coastal areas on the pink flowering variety.

Aceria lantanae has spread to 23 new locations (>500m from a release site), all on the pink variety. Most notably, A. lantanae has been detected across hundreds of kilometres spanning Charters Towers through to the coast, and from Townsville to south of Home Hill (Figure 2.). The furthest distance A. lantanae has been detected from a known release site is approximately 50 km (Figure 2.). In South Africa, dispersal rates varied of A. lantanae between six and 40.6 km per year, averaging 25.8 km per year (Mukwevho et al. 2017a). Natural dispersal of A. lantanae is by crawling from one plant to another, catching wind currents by crawling to the mature gall surface (prior to the gall senescing), phoresy (on birds or insects) or by rain (Sabelis and Bruin 1996, Michalska et al. 2010).

Within northern Queensland, the altitude of established sites ranged from 6 metres (Cape Cleveland) to 323 metres (Kuranda) above sea level with associated large differences in climatic conditions. Consequently, there appears to be no distinct preference of A. lantanae for establishment or spread within northern Queensland. Similarly, establishment of A. lantanae within South Africa was not affected by altitude and it varied within the same region and between climatic regions (Mukwevho et al. 2017b). It was found established in drier inland regions as well as humid coastal regions and is classified as widely 12 established with sporadic pattern and performance, based on varietal differences and peak flower production (Mukwevho et al. 2017a). All of these factors are seen in northern

Queensland, with gall formation inconsistent with known varietal preferences e.g. galls Page

formed on pink flowers but not on pink-edged red flowers on adjacent nodes on the same plant (Figure 1d.).

IMPACT

Over 100 galls have been counted within a cubic metre of lantana bush at several locations, severely affecting the flowering and growth of the bush. Lantana camara is still capable of producing seeds on gall-infested flower heads, but production is severely decreased. Aceria lantanae has persisted over varying seasonal conditions and significantly spread unaided.

ACKNOWLEDGEMENTS

We thank the many local government, Departments of National Parks, Sports & Racing and Agriculture & Fisheries employees, landholders and Natural Resource Management groups, for their assistance in the dispersal, transport and information dissemination of Aceria lantanae in northern Queensland. Thank you to Joshua Nicholls for mapping assistance.

REFERENCES

Day, M.D. (2012). Lantana camara L. - lantana, In Biological Control of Weeds in Australia. Julien, McFadyen and Cullen (Eds) CSIRO publishing, Australia.

Day, M.D., Wiley, C.J., Playford, J. and Zalucki, M.P. (2003). Lantana: Current management status and future prospects. Australian Centre for International Research, Canberra.

Flechtmann, C.H.W. and Harley, K.L.S. (1974). Preliminary report on Mites (Acari) associated with Lantana camara L. in the neotropical region. Anais da Sociedade Entomolgica do Brasil. CEPEC, Itabuna, Brasil 3(1): 69-71.

Michalska, K., Skoracka, A., Navia, D. and Amrine, J.W. (2010). Behavioural studies on eriophyoid mites: an overview. Experimental and Applied Acarology 51: 31-59.

Mukwevho, L., Olckers, T. and Simelane, D. (2017a). Establishment, dispersal and impact of the flower-galling mite Aceria lantanae (Acari: Trombidiformes: Eriophydiae) on Lantana camara (Verbenaceae) in South Africa. Biological Control 107: 33-40.

Mukwevho, L. Simelane, D. and Olchers, T (2017b). Host-plant variety and not climtate determines the establishment and performance of Aceria lantanae (Eriophyidae), a biological control agent of Lantana camara in South Africa. Experimental and Applied Acarology 71: 103-113.

Riding, N., Pukallus, K.J. & Day, M.D. (2015). Aceria lantanae, the latest biocontrol agent for Lantana camara. In: Proceedings of the 13th Queensland Weeds Symposium. (Ed. 13 Vogler, W.). Pp. 67-70. Weed Society of Queensland.

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Sabelis, M.W. and Bruin, J. (1996). Evolutionary ecology: life history patterns, food plant choice and dispersal. In Lindquist, E.E, Sabelis, M.W & Bruin, J. (eds). Eriophyoid Mites: their Biology, Natural Enemies and Control. Elsevier, Amsterdam, Netherlands. Pp 329- 366.

Smith, L.S. and Smith, D.A. (1982). The naturalised Lantana camara complex in eastern Australia. Queensland Botanical Bulletin 1: 1-26.

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Figure 2. Map of northern Queensland showing Aceria lantanae release and detection 14 sites. Page

Figure 3. CLIMEX model Ecoclimatic Index (EI) values for Aceria lantanae in Queensland. The higher the value the greater the suitability for Aceria lantanae.

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IMPLEMENTATION OF THE LAND PROTECTION FUND CO- INVESTMENT MODEL

Kristy Gooding Local Government Association of Queensland, PO Box 2230, Fortitude Valley, BC, QLD 4006

ABSTRACT

The Local Government Association of Queensland in partnership with Biosecurity Queensland has recently implemented the Invasive Plants and Animals Co-investment Model which involved the development of improved governance arrangements between the State and local government. The project involved the establishment of Regional Pest Management Sub-committees to prioritise and facilitate the delivery of invasive plant and animal control actions on a regional scale. A Statewide Oversight Group was also established to guide research and on-ground works at a state level. Importantly, the model allows for improved communication between state and local government, and the inclusion of NRM groups and industry bodies in invasive plant and animal decision making.

INTRODUCTION

The Land Protection Fund collects approximately $2.8 million per annum in local government contributions in addition to State government co-investment to manage and support strategic weed and pest animal control initiatives in Queensland. The Biosecurity Act 2014 outlines that appropriate activities that may be funded from the Land Protection Fund include: research about managing invasive animals and plants in the local government’s area; the maintenance of an invasive animal board of any part of the barrier fence; or acting under a biosecurity program for invasive plants or animals in the local government’s area.

Local governments had expressed a desire to move from the existing Land Protection Fund annual payment arrangements to a more transparent and accountable system allowing them greater control over the outcomes delivered from these funds.

The LGAQ and the Department of Agriculture and Fisheries (DAF) undertook to develop a new Invasive Plants and Animals Co-investment Model. The model finalised in 2014, was developed consultatively between members of DAF and local government. The Model is a new approach that includes state and local government joint decision making and will allow investment by other parties. The Model involves new Land Protection Fund governance arrangements which are as follows: • Formation of Regional Pest Management Sub-committees (RPMS) to inform the priorities for Land Protection Fund expenditure; 16 • Formation of a State-wide Oversight Group (SOG) to oversee the expenditure of on-ground and research funds from the Land Protection Fund and; Page

• Reporting to the Minister for Agriculture and Fisheries and the LGAQ Policy Executive by the SOG.

In 2016, Biosecurity Queensland funded the LGAQ to implement the Invasive Plants and Animals Co-investment Model.

PROJECT OBJECTIVES

Implementation of the co-investment model included three main objectives: 1. The formalisation of Regional Pest Management Sub-committees within regional local government decision-making forums; 2. The establishment of a Statewide Oversight Group; and 3. Determination of an agreed funding methodology for the on-ground and research component of the Land Protection Fund.

PROJECT DELIVERABLES

Establishment of Regional Pest Management Sub-committees

Regional Pest Management Sub-committees were formed on the basis of the Regional Organisation of Councils (ROC) groupings as suggested in the Co-investment Model. Each ROC was approached by the LGAQ and provided an opportunity to be briefed on the project. Ten sub-committees have been established across the State according to the following ROC groupings: • Council of Mayors South East Queensland • Wide Bay Burnett Regional Organisation of Councils • Far North Queensland Regional Organisation of Councils • North West Queensland Regional Organisation of Councils • North Queensland Regional Organisation of Councils • Remote Area Planning and Development Board • Whitsunday Regional Organisation of Councils • Darling Downs South West Queensland Council of Mayors • Central Queensland Regional Organisation of Councils • Torres Strait Invasive Species Advisory Group

The establishment of the sub-committees involved numerous face-to-face briefings and teleconferences. Once each group was established, a regional invasive plant and animal prioritisation workshop was held. Biosecurity Queensland collated data from each council’s Pest Management Plan to develop a list of regional priorities. The workshop process allowed for the generation of priority species and priority project lists, developed by consensus. In total, twelve regional workshops were delivered in tandem by LGAQ and Biosecurity Queensland and were well received by local government participants.

The benefits of the workshops were numerous including the establishment of working relationships across a number of sectors in relation to biosecurity, participation of 17 biosecurity research staff to provide updates regarding the latest information in relation to biocontrols, new herbicides and establishment of integrated management techniques, and

improved communication between Biosecurity Queensland and local government staff. Page

Each RPMS will be able to use the prioritisation process to develop projects (through Expressions of Interest) to the Land Protection Fund on an annual basis. Regional Pest Management Sub-committees will provide a framework for regional decision making regarding invasive plant and animal issues into the future.

Establishment of a state-wide oversight group

The purpose of the SOG is to oversee the development, alignment and implementation of projects that are funded through the Land Protection Fund. In response to the call by local government for greater transparency in how the Land Protection Funds are calculated and spent, the SOG was responsible for providing recommendations on the options presented for a revised calculation methodology for the On-ground and Research component of the Land Protection Fund.

Biosecurity Queensland invited participating councils in each RPMS to nominate a regional representative to sit on the SOG. The SOG membership consists of one member from each RPMS as well as one representative from both Biosecurity Queensland and LGAQ.

Beyond the review of the calculation methodology, the SOG will concentrate on delivering a communication strategy that focuses on improving the communication from Biosecurity Queensland to local government about how the Land Protection funds are spent. The SOG will also assist to determine how the On-ground and Research component of the Land Protection funds are expended to ensure regional and state-wide priorities are being addressed and that local government has significant input into the decision-making process.

Calculation methodology review

A key component of the project included a review of the calculation of individual local government contributions to the on-ground and research component of the Land Protection Fund. AEC Group Pty Ltd were contracted to deliver this piece of work which has resulted in the development of an Issues Paper, an Options Paper and a final Recommendations Paper. AEC Group Pty Ltd consulted with local government to identify the current issues with the calculation methodology. Further consultation regarding the development of potential options was undertaken via the SOG.

Issues Paper

The Issues Paper documents what local government stakeholders believed to be the main concerns associated with the current Land Protection Fund calculation methodology. Local government consultation revealed a strong desire to review the current calculation methodology. Through the consultation process, a number of issues with the calculation methodology and the use of the funds were identified by local government: • Limited understanding of how the methodology was developed; • Transparency and reporting of the investments and outcomes; • Capacity to pay; • Communication and engagement; and

• Implementation of proposed changes 18

Options Paper Page

Consultation with local government highlighted a number of parameters considered to be appropriate for inclusion in the calculation methodology. The Options Paper documents a range of scenarios based on a number of parameters and weightings. These parameters were confirmed at the first SOG workshop on the 19th April 2017. The parameters included in the scenarios are: Gross Value of Agricultural Production, general rates, and environmental parameters. The second workshop of the SOG concluded that the most appropriate environmental parameter to be included is current infestation. Potential infestation will remain in the calculation methodology as a zero percentage until such time that this data is rigorous enough for inclusion in the model.

Final recommendations

The final paper produced by AEC Group Pty Ltd outlines the process taken to arrive at a final recommendation for a revised calculation methodology. The Statewide Oversight Group developed a number of principles for consideration in the development of a new contribution calculation. Additionally, the SOG considered a range of parameters and weightings through the development of a number of potential calculation methodology scenarios (see Table 1).

The potential infestation is considered an important parameter; however, due to low levels of confidence in the data at this point in time, this parameter was given a 0% weighting. However, where additional and appropriate data is available in the future, the weighting should be revised. This scenario was observed by the SOG to present the scenario containing fewer dramatic spikes than other scenarios examined.

Whilst not discussed at the SOG meetings, AEC Group Pty Ltd have recommended that payments be capped at a maximum of $20 per capita, and the remaining funds should be collected and redistributed across other contributing parties. This recommendation reflects the principle of fairness adopted by the SOG.

Future work

Through consultation with local government, communication and engagement about the use of the Land Protection Funds was the most important issue. The SOG will focus its work over the next twelve months to improve the transparency and accountability of the current method of reporting and develop improved communication methods about latest research and how the funds are being spent.

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Table 1. Parameters for inclusion, their weightings and rationale for inclusion in the new contribution calculation.

Parameter Weighting Rationale

Queensland Agriculture, 57.5% An average over the preceding Forestry and Fishing GVA three years was identified as the (average of the previous three most appropriate means to years) incorporate the agricultural GVA estimate to address any short- term variability issues (for example, climatic seasonality or relatively volatility of some of the input parameters, such as the ABS’ Labour Force Survey data). Agriculture was given the largest weighting to retain consistency with the existing methodology and to recognise the importance biosecurity has to agriculture.

General Rates 32.5% General Rates was included as a measure as it was identified to best represent population mass and distribution, capacity to pay and is an accurate and comparable measure across the state.

Current Infestation 10% This was included to highlight and provide representativeness of the current levels of infestation throughout Queensland.

Potential Infestation 0% This was included to highlight and provide representativeness of the potential/ threat of infestation throughout Queensland. However, there was not sufficient confidence in the data to apply a score in the weighting. It is anticipated that the ensuing five years will see additional research and modelling around the potential future infestation.

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ERADICATION OF RED WITCHWEED – ONE STEP AT A TIME!

Peter J. Austin1, Daniel C. Stampa1 and Joseph S. Vitelli2 1 Biosecurity Queensland, Department of Agriculture and Fisheries, PO Box 668, Mackay, QLD 4740, Australia 2 Biosecurity Queensland, Department of Agriculture and Fisheries, GPO Box 267, Brisbane, QLD 4001, Australia

ABSTRACT (SUMMARY) The parasitic weed, Red witchweed (Striga asiatica) (L.) Kuntze) was first recorded at Habana, near Mackay in July 2013, the only known infestation to have established in Australia. An eradication response program was endorsed and commenced 1 July 2015 involving a treatment period of 3 years. A ‘targeted adaptive three zone approach’ was adopted, utilising the integration of three treatment methods (planting of false host crops, herbicides and ethylene fumigation) to specific sections, or zones, within each infested property, with the aim to expedite RWW soil seedbank depletion and minimise emergence. This paper will outline the treatment progress made to date and challenges encountered. The planting of the false host, soybean, in the high priority zone was completed in 2015- 16, 2016-17 & 2017-18. High rainfall occurring in the RWW area during 2016 (1607 mm) and 2017 (2100 mm), necessitated an active weed control program within the soybean crop. Potential grass hosts amongst the soybean; needed to be destroyed before RWW could germinate, establish and set seed. To accelerate RWW soil seed bank run-down ethylene gas was also injected into the soil at 1.5 to 2.0 kg/ha using a custom-made delivery system during the autumn period. Once delivered ethylene gas disperses readily through the soil from the point of injection, saturating the soil profile, initiating germination of any red witchweed seed in the soil that are in a pre-conditioned state. An integrated research field trial (efficacy trial) has also been established on an infested property examining 16 control options to help govern the management strategies utilised within the RWW eradication program. Keywords Striga asiatica, Red witchweed, eradication, treatment.

INTRODUCTION

History

Red witchweed (Striga asiatica) was confirmed on a 103.63 hectare sugar cane property at Habana, near Mackay, on 11 July 2013, and was the first confirmed identification in Australia.

In Africa, various species of witchweed collectively cause an estimated $7 billion damage per year to various grain crops. In the United States of America (USA), an eradication project targeted at Red witchweed has been running for 50 years at a cost of more than US$250 million (Eplee 1992; Sand 1987). Red witchweed can also impact on trade, as a

number of Australia’s trading partners have import restrictions on seed and grain 21 originating from countries where Red witchweed is known to occur (MICoR 2013). Page

Lifecycle

Red witchweed is a parasitic plant that produces 90,000 – 450,000 tiny, dust-like seeds per plant (Bebawi et al. 1984a; Bebawi et al. 1984b) that grows attached to the roots of suitable hosts, including commercially important grasses and summer cereals such as sugarcane, sorghum, maize, rice, wheat and barley (Figure 1).

22 Figure 1. Red witchweed (Striga asiatica) hosting off sugarcane.

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Red witchweed characteristics include: • Seeds take 18-24 months to be preconditioned for germination (favourable soil moisture & temperature); • Seed germinates and lives below-ground for approx. 4 weeks and flowering occurring in 16-18 days of emergence; and • Seeds have potential longevity of 9-14 years.

Eradication Response – Treatment Approach The Eradication Response Plan 2015-2025 covers for the eradication of Red witchweed for a period of 10 years starting July 2015. A ‘targeted three zone approach’ has been employed during the 10-year eradication strategy applying the integration of three treatment methods (planting of false host crops, soil fumigation and herbicides) to specific sections, or zones, within each infested property (IP).

The three zones include: Zone A. – confirmed Red witchweed sightings, where the area is buffered to 30 metres from known detections of Red witchweed. If the 30 metre buffer encroaches into a crop area the crop is taken out of production; Zone B. – this area extends from the outer perimeter of Zone A for further 30 metres (hence, the area that is 30 - 60 metres from each point where a Red witchweed plant has been detected). Zone C. – comprises of the remaining area of an infested property outside Zones A and B.

Surveillance Surveillance and monitoring is undertaken every 5-14 days across all infested properties throughout the year. The optimum period for Red witchweed germination occurs from January – May period when eradication surveillance focuses on early detection of flowering plants and the prevention of any plant going to seed. During this period, surveillance of Zone A areas ensures all IP’s have been surveyed within 5-8 day cycle. Any site with a positive detection are re-visited daily until the site is deemed clear, with plants found destroyed.

Zone treatments Zone A - areas are subject to an integrated control program combining the use of false hosts, catch crops, herbicides (pre- and post-emergent), and soil fumigants (ethylene gas and dazomet fumigation).

False host crop (soybean) grown in Zone A are kept as long as possible, as they stimulate the suicidal germination of seeds of Red witchweed without attachment, thereby helping to reduce the quantity of Red witchweed seeds in the soil.

The catch crop (corn) is also strategically planted in Zone A areas for a period of 2-3 months during treatment period, as an indicator of abundance and/or presence or absence of Red witchweed. Corn has the ability to trigger germination and attachment of Red witchweed. 23

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Ethylene gas (soil fumigant) is the “backbone” of the eradication tools and is used in conjunction with the false host or applied in fallow in Zone A areas (Figure 2). Ethylene gas is applied to Zone A at least once per annum and if suitable ground conditions exist, twice a year. Soil moisture and temperature levels determine what time of year ethylene gas can be applied.

Figure 2. Tractor mounted ethylene injection system.

During winter, dazomet (a dry formulation fumigant) is applied evenly to the soil surface at a rate of 330 kg/ha to targeted Zone A areas. For activation and soil incorporation dazomet requires 10 to 25 mm of rain within a few days of application to move the material into the soil profile.

Pre-emergent and post-emergent herbicides are applied throughout the treatment period in accordance with APVMA permit requirements.

Zone B. Areas within cane paddocks are regularly monitored by the program response staff and treated accordingly with herbicides. IP owners also undertake passive surveillance and support control activities by undertaking normal production spray treatments.

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Zone C. No treatment are applied to Zone C areas. Stringent hygiene practices are in place for machinery and other risk items required to work and upon leaving Zone A and B. Zone C areas follow industry best practice hygiene requirements.

Detections – Grid Mapping The eradication response program has moved to a grid based (10m X 10m area) mapping system (referred as a management grid) to record the presence and absence of Red witchweed on infested properties. In 2016-17 period, a total of 942 Red witchweed plants were detected in 132 grids, representing 8.41% of Zone A areas on 1IP, 2IP, 4IP, 5IP and 80IP. NO seed bearing plants were detected during the 2016-17 period. Whilst detections have occurred, 95% of clear management areas exist across all infested properties.

Efficacy Trial

A research trial agreement was signed with the owners of 4-IP to establish an integrated control efficacy trial, to investigate the use of false host plants, host plants, herbicides and fumigants aimed at reducing the viability of red witchweed in the field, over a ten year period. The efficacy trial aims to develop reliable and effective control options that can be integrated into the red witchweed eradication program.

To determine treatment effectiveness, 1000 canisters containing 5800 satchels have been buried in the field. One hundred canisters are exhumed annually and red witchweed seed viability tested following the annual application of treatments (Vitelli et al 2016).

Twenty four months retrieval data from the 4-IP integrated trial is showing some encouraging trends. As seed burial depth increases from surface to 500 mm deep, seed viability increases from 33 to 59%. The fumigant, ethylene (6%), is having the biggest reduction in seed viability. After 24 months of seed burial the false hosts, cotton, soybean, cowpea and lablab, have reduced red witchweed seed viability to 51, 52, 58, and 60, respectively. Whilst the true hosts corn, sorghum and sugarcane, reduced red witchweed seed viability to 35, 42 and 74 %, respectively. The preliminary data indicates that through the use of ethylene, a false or true host, the time required to exhaust the soil seed bank may be achievable within 3 to 5 years.

ACKNOWLEDGMENTS

The Red witchweed Eradication Response is nationally cost shared response apportioned to government jurisdictions including the Commonwealth, Queensland, New South Wales and the Northern Territory and Industry including MLA on behalf of Cattle Council and live export sector, Grains Producers Australia and Canegrowers. The authors acknowledge the financial assistance provided by all funding partners.

REFERENCES

Bebawi, F.F., Eplee, R.E., Harris, C.E. and Norris, R.S. (1984a). Longevity of witchweed 25 (Striga asiatica) seed. Weed Science 32, 494–497. Page

Bebawi, F.F., Eplee, R.E., and Norris, R.S. (1984b). Effects of seed size and weight on witchweed (Striga asiatica), seed germination, emergence, host-parasitization. Weed Science 32, 202–205.

Eplee, R.E. (1992). Witchweed (Striga asiatica) - an overview of management strategies in the USA. Crop Protection 11, 3–7.

Sand, P.F. (1987). The American witchweed quarantine and eradication program. In ‘Parasitic weeds in agriculture. Volume I. Striga’, eds L.J. Musselman, pp 207-223. (Department of Biological Sciences, Old Dominion University, Norfolk, Virginia).

Vitelli, J.S., Williams, A.M., Riding, N., Chamberlain, A.A., Austin, P., and Stampa, D. (2016). Operation witch hunt: conjuring eradication of the parasitic red witchweed plant with trickery and potions. Proceedings of the 20th Australian Weeds Conference, eds R Randall, S. Lloyd and C. Borger, pp. 292-295 (Weeds Society of Western Australia, Perth).

MICoR 2013, Manual of Importing Country Requirements. Australian Government, Department of Agriculture Fisheries and Forestry http://www.daff.gov.gov.au/micor/plants

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SIAM WEED (CHROMOLAENA ODORATA) THE RECENT PAST AND OPTIONS FOR THE FUTURE

David Green Biosecurity Queensland, Department of Agriculture and Fisheries Centre for Wet Tropics Agriculture, PO Box 20, South Johnstone, 4859

ABSTRACT There has been much spoken about Siam weed (Chromolaena odorata) and the relative merits or otherwise of ceasing to pursue eradication in 2012. Since the closure of the eradication program, management of Siam weed has been supported by members of the Siam Weed Management Group, advised by the Siam Weed Management Strategy, with on-ground action being conducted by relevant landholders and managers. Further to this, Siam weed has been scheduled as restricted matter category 3, under the Queensland Biosecurity Act 2014. Since the closure of the eradication program Siam weed is expanding its range around known areas, and has also been detected in several catchments previously thought to be free of the weed. This paper will summarise; Current known extent of Siam weed in Queensland; Summary of on-ground efforts in some priority areas over the last 5 years; Options for future management, including a summary of the draft Siam Weed Management Strategy 2018–2023.

Key words: Siam weed, on-ground effort, future management.

INTRODUCTION

In response to the first detection of Siam weed on mainland Australia, in 1994 near Bingil Bay in north Queensland, a cost-shared National Siam Weed Eradication Program (NSWEP) was established. In 2012, the cost share partners agreed that eradication of Siam weed from mainland Australia was not feasible, and the NSWEP ceased (Biosecurity Queensland 2012)

Following on from the NSWEP, stakeholders and managers have continued oversight of

activities supporting Siam weed management through participation in the Siam Weed 27

Management Group, and other regional and local planning processes. A Siam Weed Management Strategy was drafted in 2013, and is currently under review. Page

DISCUSSION

Zone Recommendations from the Siam Weed Management Strategy 2013 The strategy identified three zones (see Figure 1: Biosecurity Queensland 2013) to help prioritise management actions needed to contain and limit the impact of current and future Siam weed infestations: Siam Weed-Free Zone; Prevention and Removal Zone; and Impact Reduction Zone. Known Distribution This paper will focus on areas outside the Impact Reduction Zone, and Figure 2 identifies where Siam weed has been detected post eradication program outside this zone. Figure 2 includes the year of detection (note: not the date of infestation). It has proven difficult to estimate the age and identifying a specific source of most infestations. Some judgements regarding age of infestations can be made due to the relative size of any infestation, size of the basal ball and the number of stems (‘leaders’) in the larger plants, however growth can be site specific and there are no empirical measurements to comprehensively determine age of infestations. Under the strategy, Biosecurity Queensland collated spatial information on infestations in zones i and ii, but not zone iii. Further to this, one of the challenges facing the Siam Weed Management Group at present is the capture and recording of absence data. Some detections outside of the Impact Reduction Zones are of single plants (to date), while others, listed below, consist of larger infestations: − Shoalwater Bay; − Emu Creek (detected towards the end of the NSWEP); − Mary Farms; − Goldsborough/ Mulgrave River; − Tinaroo Falls Dam; − Lower Herbert River − Magnetic Island. Summary of on-ground efforts in the Impact Reduction Zones Control of Siam weed in the Impact Reduction Zones has largely been the responsibility of the relevant local government and landholders. Removal of Siam weed infestations along roadsides has been a priority in these areas, however in more recent years reports of

Siam weed increasing in the Impact Reduction Zone may put additional pressure on the 28 roadside maintenance, and subsequently increase the risk of long range spread. Roadside management is not the only activity in the Impact Reduction Zones; providing Page

control advice to landholders and usually neighbouring properties occurs regularly during flowering season, and controlled burns have been used to suppress some infestations in these zones. Identification of areas posing high risk to long range spread of Siam weed has led to increased control in those areas, and efforts to protect areas like National Parks continue.

Figure 1. Distribution of Siam weed in Queensland (Biosecurity Queensland 2013).

The Douglas Shire Council have continued to support land owners in this shire to remove Siam weed from the local government area, and Cairns Regional Council also conducts survey and control along the Russell River, and in support of the recent detections along the Mulgrave River. Future Management Summary of the (draft) Siam Weed Management Strategy 2018 – 2023 At the time of writing there is a review of the Siam Weed Management Strategy being undertaken. This paper provides a summary of some of the discussions to date, however what is carried forward into the revised strategy is yet to be determined. During consultation, stakeholder groups have identified a need for a revised strategy to support

on-going coordinated management of Siam weed, in particular in outlier infestations, and

to also support their own internal and external funding bids. There are substantial areas of 29

Queensland as well as other areas of the mainland and offshore Australia that are thought Page

to be free of Siam weed. The rate of spread of Siam weed within Queensland will likely be influenced by the level of control occurring in known infestations. The general language used in the revised management strategy should better reflect the change in legislation to the Biosecurity Act, 2014, and may benefit from including recommendations regarding processes to achieve improved Siam weed management utilising local government biosecurity plans, and subsequent surveillance or prevention and control programs.

Figure 2. Areas where Siam weed has been detected post eradication program outside the Impact Reduction Zone.

During the review of the strategy, it has been identified that local government biosecurity planning processes have advanced in many areas since 2013, and the Siam Weed Management Strategy should reflect these changes. For example, ensuring language used to describe zonal arrangements become consistent: − Weed Free Zone to become Prevention Zone; − Prevention and Removal Zone to become Intensive Control Zone; and − Impact Reduction Zone to become Asset Protection Zone.

There has been recognition that the original zone boundaries were not aligned to 30 geographical or readily identifiable locations, and that this might be improved by aligning the boundaries to catchments. This would also likely support the strategy being scalable,

and more useable at the state, regional, local, and sub-catchment levels. Page

The management group may also explore options to improve the asset identification process and the reporting of activities that targets the protection of these assets. Areas currently being explored include establishing criteria to determine assets at risk from the impact of Siam weed infestation, and assets at risk of infestation due to proximity to infestations. More control tools Biosecurity Queensland is currently working on several tools to increase options for Siam weed control. Once efficacious options are identified, the next steps will be to confirm how they can be integrated to achieve management objectives other than eradication. Biological control agent – application to release has been submitted to the relevant agencies; Pre-emergent herbicide – trial underway at Charters Towers Research Centre; Impact of controlled burn – trials completed, internal review of paper occurring; and Low volume, high concentration herbicide application – available now.

ACKNOWLEDGEMENTS The transition away from a fully funded eradication program has not been easy, and the author recognises, acknowledges and thanks all stakeholders who continue to participate in planning mechanisms, and on-ground control of Siam weed. In particular members of the Siam Weed Management Group, relevant local government staff, state agencies and individual land managers undertaking awareness raising and on-ground control actions are acknowledged. Those stakeholders managing infestations in the Impact Reduction Zone, in particular local governments, merit additional mention for their on-going efforts to limit the rate of spread of Siam weed. There would be significantly more Siam weed present in Queensland’s landscape without these efforts. The on-going research effort by Biosecurity Queensland Science staff, and their interactions with Siam weed control practitioners is also acknowledged, and will be vital to improving integrated control recommendations in to the future.

REFERENCES Biosecurity Queensland; Department of Agriculture, Fisheries and Forestry (2012) ‘Discussion paper: Future Management Options for Siam weed (Chromolaena odorata) in Australia Biosecurity Queensland; Department of Agriculture, Fisheries and Forestry (2013). ‘National Siam Weed Management Strategy’

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KOSTERS’ CURSE – A MULTI-AGENCY APPROACH TO MANAGEMENT

Kelly Ashwood1, Damon Sydes1 1Cassowary Coast Regional Council1 PO Box 887 Innisfail, Queensland, 4860

SUMMARY

Koster’s curse (Clidemia hirta) was first detected at a small plant nursery in Julatten, north Queensland in August 2001. The method of entry into Australia is unknown but is suspected to have been as a contaminant of packaging material. (Biosecurity Queensland 2015). In July 2015 a second infestation of Kosters' curse, (Clidemia hirta L. D. Don), was found within the Wooroonooran National Park in the Misty Mountains section of the Wet Tropics World Heritage Area. Previously Julatten was the only known location for Kosters' curse in Australia. The Julatten infestation was managed by the Biosecurity QLD under the National cost-shared Four Tropics Weeds Eradication Program (4TW). Due to the size, extent and difficult terrain the new infestation was located in, the program for Kosters' curse was deemed unfeasible to eradicate by the Consultative Committee for Exotic Plant Incursions (CCEPI). The species was withdrawn from the national eradication program and a "transition to management process" began to transition the lead role in management to local stakeholders.

Keywords: Taskforce, Kosters’ curse, eradication, transition to management

INTRODUCTION

Kosters’ curse can have a serious negative impact on the environment by forming large infestations, out-competing understorey species and smothering out native seed recruitment. The rapid growth rate, seed longevity (5+ years), bird dispersed fruits and quick maturation of plants (12 months) gives this species a distinct advantage over native rainforest species resulting in significant biodiversity impacts. While there is acceptance that eradication no longer remains a realistic management aim there was concern amongst stakeholders that allowing it to spread along road sides and walking tracks will increase maintenance costs and de-value some of our most highly valued natural and cultural assets. Kosters' is a native to tropical America but has naturalised its self in many other places including tropical parts of Africa, Madagascar and many Oceanic Islands. Kosters' curse has the ability to invade disturbed and undisturbed habitats. Appearance may change slightly depending on the location. Kosters' can reach heights of 3m in thick canopy cover and around 1m if growing out in unprotected areas. This perennial shrub has rounded stems covered with reddish hairs. Kosters' curse has five longitudinal veins 32 running down the leaf, and leaves are covered in reddish brown hairs and are quilted in Page

appearance. The shrub produces small white flowers and dark purple mature berries. These berries can be easily spread by birds, bats, pigs, machinery and humans.

Kosters' Curse is listed as a restricted invasive plant category 2,3,4,5 under the Biosecurity Act 2014. It is also an identified priority weed in the Cassowary Coast Biosecurity Plan, the Innisfail QPWS Weed Strategy and is included as a threat to the Wooroonooran National Parks Key Values under QPWS’ Values Based Planning and Management Framework.

Detection, delimitation and a transition to management.

Following on from the initial detection (Stephen McKenna) in 2015, surveys were conducted in the immediate area by QPWS staff scouring roadsides and tracks to get an idea of the nature and size of the infestation. A joint operation between the 4TW program, Biosecurity Queensland, CCRC and QPWS then conducted an extended survey (delimitation) of the area. This delimitation exercise detected a large infestation off the road network. The size, age and density of this infestation ultimately led to the decision to withdraw Kosters’ curse from the National cost-shared eradication program.

Works continued in the adjoining areas to identify the extent of the core population; control high risk plants on potential spread pathways and if possible identify the source of the infestation. In addition to controlling mature plants, longer distance surveys on road and walking track networks were conducted to define the approximate extent of the core infestation.

On the ejection of Kosters’ curse from the national cost shared program a transition to management process was initiated. A plan for the transition process was developed following detailed consultation with the immediate stakeholders for both the original infestation area in Julatten, and the new infestation in Wooroonooran National Park. The plan included two key areas of support for the Wooroonooran response from the 4TW program; the storage of data collected during operations; and the conducting of herbicide trials to establish foliar herbicide rates to control plants within the core infestation.

In the first stages of the transition to management QPWS were funded by the 4TW transition program to continue survey and control works. With these funds QPWS continued to carry out works on road sides to reduce the risk of spread. To further establish information about the infestation, and to ascertain the size and extent, the first multiagency "taskforce" operation was conducted in 2016. In 2016 the Cassowary Coast Regional Council (CCRC) put forward a proposal to the Local Natural Asset Management Advisory Committee (NAMAC) to gain support from stakeholders and to determine its priority status within the region and consider its’ inclusion in the CCRC Biosecurity Plan. A prioritisation process determined that Kosters’ curse was a "very high priority" and given its potential for significant impacts in the region, and history in similar overseas locations, that a multiagency approach would be the best way forward. CCRC hosted a local stakeholder taskforce at the Wooroonooran National Park site to map the extent of infestation and develop a plan for long term management. Stakeholders including Queensland Parks and Wildlife (QPWS), Biosecurity Queensland (BQ), Cassowary Coast Regional Council (CCRC), Traditional Owners Environmental Team (TOES) and Tablelands Regional Council (TRC); all agreed to commit personnel to the project for a 3 year period followed 33 by a review and discussion for a strategy plan for future management.

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Challenges

The current infestation in the Wooroonooran National Park is located in some very unforgiving country with many steep to vertical cliff faces present in dense rainforest vegetation. This area has also been impacted by two major cyclones (TC Larry 2006, TC Yasi 2011) that have created many disturbed areas that are ideal for Kosters' recruitment. Previous logging activities prior to WHA declaration have also left disturbed areas for the species to recruit into. In many areas where vegetation has been disturbed there are very thick patches of wait-a-while (a native vine covered in sharp, hooked spines) making access difficult, slow-going and at times extremely dangerous. The scale and complexity of the job has meant that a multi-agency approach to management is the best way forward. By utilising and sharing the combined resources of all the agencies involved, stakeholder's skills, knowledge and experience will benefit this project and make it sustainable into the future.

Figure 1. location of the Misty Mountains infestation 130 kilometres from the existing infestation area at Julatten and The Wet Tropics World Heritage Area (left). Dense vegetation in steep terrain makes survey work hard going (right). Image Chris Roach, QPWS.

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Figure 2 the infestation area is dominated by steep ravines (left). Kosters’curse takes advantage of disturbance and clearings within the rainforest (right). Images Chris Roach QPWS. TASKFORCE OPERATIONS

Although the immediate response efforts were unable to identify the source of the infestation, there was a degree of confidence that it was an isolated occurrence albeit one with an unknown origin. Managers were optimistic that the early management steps taken to suppress the seedbank, control mature plants and limit the opportunities of spread of soil-borne seed from roads and tracks significantly reduced the risk and set the scene for the next phase of management.

Following on from these efforts the initial taskforce operation focused on delimitation surveys to determine the footprint of Kosters' curse within the World Heritage area with the assistance from committed stakeholders. Subsequently, CCRC were successful in acquiring funds from the Queensland Feral Pest Initiative to carry out on-ground operations in the core infestation area over a 3 year period. Taskforce operations will continue to focus on extended surveys for outlying infestations, whilst contract works will treat all known sites. The project aims to prevent new seeding events from occurring; reduce the core infestation size; and minimise the risk of spread to surrounding high value agriculture land by containing the infestation within the Wooroonooran National Park. Other activities in conjunction with CCRC’s Biosecurity Plan and advisory group (NAMAC) are also delivering community education and awareness programs as well promotion and awareness raising through various media outlets.

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Figure 2. a). Original detection and transition to management surveys. b). 2016 taskforce c) 2017 taskforce and new detections beyond core infestation d) QPFI-TOES contract works undertaken in 2017 and wider QPWS delimitation of track network (Data from QPWS and 4TW) Taskforce one

The first Taskforce event hosted by CCRC in October/ November 2016 proved to be successful with large numbers of dedicated staff from all stakeholders attending the week long operation. No new detections were found to be present outside of the core infestation. Averaging 19 people on ground per day with 508 person hours delivered on ground over the week. The results from the taskforce operations identified that the current infestation size is spread across approximately 30Ha of rainforest and includes approx. 2km of publicly accessible roadsides. Taskforce two The second CCRC hosted Taskforce was held in August 2017 with over 100ha successfully surveyed over a 3 day period. During the Taskforce operations 9 new detections beyond the core were made to the north, west and east, out to around 200m from the known infestation. This was disappointing, but expected due to the extremely difficult nature of the terrain and known dispersal methods. The survey averaged 1.93ha per person per day with a total of 456 person hours on ground for the week operation. Following the Taskforce a further 320 hours were dedicated to treatment of roadsides, walking tracks and the core infestation site. These works were carried out in conjunction with the Traditional Owners Environmental Services team funded through the Queensland 36 Feral Pest Initiative.

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CONCLUSION

The data collected and collated from the taskforce operations indicate that the current distribution is restricted to a core area with outlying fringes around the known infestation. With regular works being carried out in these areas over a 3 year period it is anticipated the core size and extent will reduce and the risk of further spread along with it. If all plants are removed before they have a chance to reproduce, seed banks will be run down and Kosters’ curse may be able to be contained to its current infestation area minimising the threat to the surrounding World Heritage Rainforest and surrounding high value agriculture land. It is clear from the first two taskforce operations that the key to successful suppression will be to continue with a multi-agency approach to management through the current 3 year commitment given by stakeholders. The continuation of the partnership will provide a greater chance of containing Kosters’ curse and reducing the impacts on the natural and cultural values of the Wet Tropics World Heritage Area, and the future risk to the economic value of agricultural land in the region. Keeping Kosters’ curse high on the priority list within the Cassowary Coast Biosecurity Plan, Innisfail QPWS Weed Strategy as well as the will benefit all stakeholders and landowners as well as the broader community. Stakeholders in the partnership look forward to seeing some great results in the near future regarding the reduction of core size and successful containment of Kosters’ within the Wooroonooran National Park.

Figure 3 Kosters' curse fruits make it attractive to most rainforest birds (right) and a dense infestation in Maui, Hawaii, provides an example of the potential impact of Clidemia hirta in the Wet Tropics

ACKNOWLEDGMENTS

Cassowary Coast Regional Council would like to thank the following for their ongoing support in the Misty Mountains Kosters’ curse response; Queensland Parks and Wildlife Service, Biosecurity Queensland, Tablelands Regional Council, Traditional Owners

Environmental Services, CCRC staff and Local Natural Assets Management Advisory 37 Committee. Queensland Feral Pest Initiative Funding and In-kind stakeholder Page

contributions In particular Chris Roach, QPWS, and Michael Graham BQ for their dedication

REFERENCES

Biosecurity Queensland (2015), Plan for Transition to Management of Kosters’ curse (Clidemia hirta).

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ADVANCING PRICKLY ACACIA MANAGEMENT THROUGH THE WAR ON WESTERN WEEDS INITIATIVE

Nathan March1, Wayne Vogler2 and Kunjithapatham Dhileepan 3 1 Biosecurity Queensland, Department of Agriculture and Fisheries, P.O Box 53 Cloncurry, Queensland 4824, Australia. 2 Biosecurity Queensland, Department of Agriculture and Fisheries, Tropical Weeds Research Centre, P.O Box 187 Charters Towers, Queensland 4820, Australia. 3 Biosecurity Queensland, Department of Agriculture and Fisheries, Ecosciences Precinct, GPO Box 267, Brisbane, Qld 4001, Australia

ABSTRACT

Prickly acacia (Vachellia nilotica) is a landscape level weed problem affecting large areas of western Queensland and other areas of the state. Following high rainfall related mass germination events of 2010 – 2012, the Department of Agriculture and Fisheries (DAF) launched the War on Western Weeds (WoWW) initiative in 2013. WoWW focussed on three key areas: refining new tools and approaches; improving biosecurity systems; and, exploring biocontrol opportunities. Notable outcomes have included: refinement of misting, weed sniper and skattergun as control options; two Good Neighbour Program case studies demonstrating the practicalities of property boundary weed-free buffer zones; ecological studies as a basis for seed spread prevention actions; and, renewed biological control investigations involving searches for prospective agents in India and North Africa. Initiative results have been extended through forums, field days and publication of a decision support tool factsheet series. The increased capacity, skills, tools and motivation from the WoWW initiative are helping to achieve practical and cost-effective outcomes for prickly acacia management – helping land managers to help themselves.

Keywords: Prickly acacia, Vachellia nilotica, War on Western Weeds

INTRODUCTION

The WoWW project is a five year DAF-funded initiative aimed at improving the management of prickly acacia through refinement of new tools and approaches; improving biosecurity systems; and, exploration of biocontrol opportunities. Complementary to these is the promotion of best practice management to reduce long term impacts of the weed. Delivery of the WoWW initiative is through a ‘Community of Practice’ approach that utilises community and industry input for all project processes. In particular, a project advisory group directs and supports research and extension priorities.

REFINING NEW TOOLS AND APPROACHES

Adaptive management trials - harnessing community innovation

Nine new management tools driven by community innovation were evaluated under field conditions. Spray misting, weed sniper and the skattergun (Figure 1) are examples of 39 successful community innovations for herbicide application where few similar tools were available.

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Spray misting using an agricultural mist blower has been shown to be an effective, lower labour method for foliar herbicide application to both long linear infestations (e.g. drainage lines) and denser thickets of immature prickly acacia. Following early landholder development, trials were conducted to formalise the herbicide application rates, weather conditions and methods for prickly acacia spray misting. This has resulted in the APVMA issuing minor use permit PER82366 for the use of spray misting for prickly acacia control.

Cloncurry Mustering Company have developed a herbicide applicator called the ‘weed sniper’ which when combined with an R22 helicopter delivers measured doses of the granular herbicide tebuthiuron for the control of prickly acacia. The use of the weed sniper allows the rapid detection and treatment of individual prickly acacia plants scattered across large, and sometimes inaccessible, landscapes. Field trials demonstrated that this device performed well in terms of cost and efficacy compared to basal bark spraying using Access™ and diesel but was slightly more costly than hand applied tebuthiuron in prickly acacia densities of 35 plants per hectare (all plant sizes) (Vogler and Carlos 2015).

The skattergun is a compressed air driven applicator for soil applied herbicides developed by Brett Epple. This device is mounted on a suitable vehicle and allows the operator to ‘shoot’ measured doses of tebuthiuron pellets up to 20 metres away from the distribution point. This enables the rapid treatment of low to high density prickly acacia infestations. Trials have confirmed that it is an efficient and cost effective tebuthiuron application method that reduces labour whilst enabling significant areas of prickly acacia to be treated quickly.

Figure 1. Agricultural mister (left), weed sniper (middle) and skattergun (right) prickly acacia herbicide application equipment.

Good Neighbour Program approaches

The establishment of weed-free property boundary buffer zones as part of Good Neighbour Program approaches was tested through case studies in the Hughenden and Muttaburra areas of western Queensland (March and Cullen 2015, March and Cullen 2017). Respective minimum buffer widths of 10 m and 250 m for fence lines and watercourses were deemed to be feasible with control operations usually quick, easy and of low to moderate cost. The identified benefits of GNPs included an immediate reduction 40 of weed seed spread between properties (Figure 2) and an incentive for landholders to progress their properties or some paddocks to weed-free status. Page

Figure 2. Good Neighbour Program approaches are reducing weed seed spread over property boundaries (left) through the establishment of weed-free boundary buffer zones (right).

IMPROVING BIOSECURITY SYSTEMS

To improve biosecurity systems, a number of ecology studies (Figure 3) were undertaken to address key gaps in knowledge and develop or refine spread prevention actions.

Riparian spread

While seeds have no intrinsic buoyancy, studies found that pods could float for up to 12 days (average 5 days) in agitated water. Subsequent field studies found that most seed deposition occurred within 7 km of a seed source although, along one creek, immature plants were observed as far as 15.2 km downstream (March et al 2015). The results have implications for riparian surveys, catchment based strategic control and Good Neighbour Programs.

Seed and pod maturity

Observations and laboratory studies found that pod and seed maturity is driven primarily by seasonal conditions with some seeds viable as early as July. Visual cues for pods and seeds were identified – firstly, that seed from flat pods and soft seeds were rarely viable, and secondly, that viability increases when pods change from green to grey. The results highlighted the need to manage risks associated with cattle grazing maturing pods and not just during latter periods of pod drop (Carlos and Vogler 2015).

Seed passage in cattle

To examine seed passage in cattle, 45 cattle were fed prickly acacia pods and sorghum stubble hay. Faeces were collected daily and seed retrieved. By the fourth day, cattle had passed 93% of seed. By day six 98% of seed had passed with the final seed found in faeces eight days after ingestion. The results indicate that to prevent seed spread, cattle movement must be carefully managed, including holding cattle in areas free of prickly acacia pods for at least six and up to eight days before or after transport or moving cattle.

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Seed longevity

Two seed longevity trials are currently being conducted using different seed sources. Seed lots have now been buried for either 3 or 8 years with viability averaging 13 and 5% respectively, which highlights the potential long term persistence of soil seed banks (Campbell 2017).

Revised biosecurity systems

Ecology research findings, relative importance of dispersal vectors and priority actions for spread prevention were discussed in a WoWW workshop at Longreach in 2015. Workshop outcomes were synthesised into recommended actions and guidelines to further reduce prickly acacia seed spread.

Figure 3. Studies of riparian seed spread (left), seed and pod maturation (middle) and seed passage through cattle (right) have assisted in refining new biosecurity systems.

EXPLORING BIOCONTROL OPPORTUNITIES

Biological control efforts commenced in the early 1980s with limited success to date. The need for an effective biological control for prickly acacia remained a high priority and was consequently progressed as a key component of the WoWW initiative.

Four prospective insects were prioritised from India for host specificity tests – a scale insect (Anomalococcus indicus), a brown leaf-webber (Phycita sp.), a green leaf-webber (Phycita sp.) and a leaf weevil (Dereodus denticollis). The scale insect and the brown leaf webber were not sufficiently host-specific to release. Host testing of the green leaf-webber and leaf weevil were abandoned due to continued difficulties in rearing them in quarantine.

With no more prospective agents available in India, survey efforts to find new biological control agents have been redirected to Africa. Based on climatic similarities and plant

phenotypic matching, Ethiopia in East Africa and Senegal in West Africa have been

prioritised for native range surveys. Surveys have commenced in Ethiopia and Senegal in 42 partnership with researchers from Central Ethiopia Environment and Forest Research Center. Gall thrips and a gall mite were identified as potential biological control agents. Page

Host specificity tests are in progress for the gall thrips in Australia while the gall mite has been exported to a facility in South Africa for colony establishment and host specificity testing. Future surveys will focus on yet-to-be-explored countries in North Africa.

ACKNOWLEDGEMENTS

• Advisory group: Scott Harrington, John Bellingham, Charles Curry (Southern Gulf NRM), Jenni Gray (Barcaldine Regional Council), Peter Spence (Desert Channels Queensland), Ninian Stewart-Moore and Robyn Young (Flinders Shire Council). • Adaptive management trials: Dr Emma Carlos, Dr Shane Campbell, Kelsey Hosking (Department of Agriculture and Fisheries); Samantha Cullen and Edward Brown (Southern Gulf NRM) and, Desert Channels Queensland for use of their mister. • Biological control research: Di Taylor, Jason Callander, Boyang Shi (Department of Agriculture and Fisheries) and overseas collaborators A. Balu, M. Murugesan, Mindaye Teshome, Stefan Neser, Anthony King and Nathalie Diagne. • Project funding: Queensland Government, Australian Government, Meat and Livestock Australia, and Rural Industries Research and Development Corporation. • The involvement of more than 50 landholders who gave their land, time and resources for field trials and other activities is gratefully acknowledged.

REFERENCES Campbell, S.D. 2017. Pers. Comm.

Carlos, E. and Vogler, W. 2015. Using pod and seed features to indicate prickly acacia seed viability. 13th Queensland Weeds Symposium, Longreach.

March, N., Carlos, E., Vogler, W., Kippers, E. September 2015. Riparian spread of prickly acacia and implications for catchment management. 13th Queensland Weeds Symposium, Longreach.

March, N. and Cullen, S. 2015. Flinders Shire Good Neighbour Program case study. Department of Agriculture and Fisheries.

March, N. and Cullen, S. 2017. Muttaburra Good Neighbour Program case study. Department of Agriculture and Fisheries.

Vogler, W. and Carlos, E. 2015. Using helicopters: taking prickly acacia control to the next level. 13th Queensland Weeds Symposium, Longreach.

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UNDERSTANDING AND IMPROVING THE BEST MANAGEMENT PRACTICE OF MEXICAN BEAN TREE IN THE WILDERNESS OF TROPICAL NORTH QUEENSLAND.

Michael Graham Department of Agriculture and Fisheries, PO Box 653 Cairns Queensland 4870

ABSTRACT

Following declaration of all species of Cecropia (Mexican Bean Tree) as high-risk pests in 2006, a concerted campaign has been implemented to detect and destroy these species wherever feasible. Since 2006, field observations have helped improve and refine the approach to management, with a best-practice approach evolving. In particular, observations have been made on key biological characteristics, including time to maturity, seed longevity, seed viability, dispersal vectors and dispersal distance. This information is an essential pre-requisite for sound management decisions.

Keywords: Mexican bean tree, Cecropia, invasive plant

INTRODUCTION

The genus Cecropia comprises 61 species, native to southern Mexico, through central America to northern Argentina. Referred to as Sloth Tree, Trumpet Tree and Mexican Bean Tree, Cecropia are fast-growing pioneer species (Csurhes 2016). Most problematic species within the genus are rainforest plants, well adapted to take advantage of natural or anthropogenic damage to rainforest canopies. Several species have become very abundant within their native ranges, generally in response to increasing land clearing and development (Conn et al. 2012). In addition, certain species, especially C. palmata and C. peltata, have established naturalised populations in parts of Africa, India, Indonesia, Malaysia, Singapore, the Pacific, New Zealand and Australia. (Conn et al. 2012)

Cecropia were actively traded around the world in the 18th and 19th centuries, mainly by botanical gardens and plant collectors (Conn et al. 2012). Elsewhere Cecropia have been introduced for other purposes including forestry, shade trees in coffee plantations and as garden ornamentals (Csurhes 2016). Cecropia are listed among the top 100 world’s worst invasive alien species (Lowe et al. 2004).

HISTORY OF CECROPIA IN AUSTRALIA AND NORTH QUEENSLAND

Distribution

The earliest record of Cecropia in Australia was in 1875 at the Brisbane Botanic Gardens. 44 In Queensland, the first detection was in 2000 on a property owned by a plant collector near Mission Beach. Since then, additional specimens and naturalised populations have

been recorded at Whyanbeel (2009), Clifton Beach (2011), Cairns City (2008), El Arish Page

(2004), Bingil Bay (2000), South Mission Beach (2010), Mackay (2008), Gold Coast (2013), Caloundra (2014), the north coast of New South Wales (2011) and Sydney (2013). Most infestations appear to be associated with botanical gardens or plant collectors.

Legislation

The Cecropia genus was subject to a process of pest risk assessment in 2004 and subsequently listed as ‘declared pests’ in 2006 under the then Queensland Land Protection Act (2002). Currently, all Cecropia species are prohibited biosecurity matter except for species that are present in Queensland, namely Cecropia pachystachya, C. palmata and C. peltata. The latter are restricted biosecurity matter as defined by the Queensland Biosecurity Act 2014. All sightings of Cecropia must be reported. In addition, Cecropia must not be kept, moved, given away, sold, or released into the environment without a permit.

Operations

Biosecurity Officers, in conjunction with multiple stakeholders, have been managing Cecropia in north Queensland since 2000. Over the past 17 years more than 1000 plants have been destroyed, including at least 500 mature specimens. Preventative management is continuing.

Description

Three species exist in far north Queensland: C. pachystachya, C. palmata and C. peltata, the latter being most common. Species are dioecious (separate male and female plants), neotropical pioneer trees, with an average height of 10 - 20 m (Figure 1). Cecropia are popular amongst plant collectors due to their unique stems (Figure 2), leaves (Figure 3) and flowers (Figure 4). (Csurhes 2016)

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Figure 1. Cecropia peltata emerging from the canopy in Garradunga in north Queensland.

Figure 2. Cecropia stems and bark; the timber is soft, stems are hollow and bark is smooth and grey with triangular leaf scars on younger branches. Trunks may be singular or coppiced and stilt roots may descend from about 1 m up the trunk.

Figure 3. Cecropia leaves; leaves on young plants are lanceolate, un-lobed and have a serrated edge. As the plant matures leaves become large (30 – 40 cm diameter), deeply lobed and densely pubescent on their underside making the surface appear silvery white. Leaves have long petioles (23 – 30 cm).

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Figure 4. Staminate (right) and Pistilate (left) inflorescences consist of a common stalk bearing a number of spikes arranged in umbellate clusters. The staminate inflorescences contain up to 50 spikes, 5 – 18 cm long, while pistillate inflorescences contain up to 14 spikes (5 to 30 cm long). The flowers in both cases are fairly inconspicuous, whereas the fruit of the female plant forms distinctive cylindrical, finger-like spikes with soft, sweet flesh surrounding the many small photoblastic seeds. (Csurhes 2016)

Ecology

Cecropia share ecological traits with many pioneer species. Their growth is rapid, from 0.7 m/year to greater than 2 m/year over the first four to five years, slowing at maturity. They recover quickly from damage to stems which triggers coppicing or vegetative reproduction from stem fragments. (Silanders & Lugo 2017)

Plants can reach reproductive maturity at 3 - 5 years. Female plants often reach maturity six months before males. The internodes between the leaf scares can be used to estimate age of plants less than seven years old when growing in areas with distinct wet and dry seasons (short internodes represent growth during the dry season and long internodes during the wet season). (Silanders & Lugo 2017)

Cecropia can live for over 30 years and produce up to 38 000 000 flowers and 6 - 7 million viable seeds. Seed viability is relatively low at 18%. Flowers are wind-pollinated. The fruit are soft and sweet, making them attractive to frugivores. Seed viability increases following passage through the digestive tract of frugivores such as birds and bats. (Csurhes 2016)

Seed longevity in Cecropia is short, compared to other invasive pioneer species currently being managed in Queensland such as Miconia species. Research on Cecropia seeds under field conditions found that seeds retained viability for only 2 to 3 months, although seeds have been successfully stored under lab conditions for more than 6 months (Silanders & Lugo 2017). Other trials involving artificial ageing of seeds suggest maximum seed longevity of up to 2 years (Biosecurity Queensland).

Cecropia seeds are photoblastic and require sustained sunlight to induce germination. Hence seeds under a closed canopy rarely germinate unless a gap forms. Alternatively, seeds that do get exposed to ideal conditions can achieve a germination rate up to 90%. Immature plants are extremely susceptible to shading and competition, with mortality rates up to 99%. However, survival rates improve once plants begin to mature, when they can

survive low light conditions for several months. (Silanders & Lugo 2017, Vázquez-Yanes

& Orozco-Segovia 1993) 47

In its native range, Cecropia flowers and produces seeds mainly in the dry season, when temperatures are lower and the day length is at its shortest (Santos 2000) Seed dispersal Page

is predominately by frugivores, movement of flowing water and soil adhering to machinery. In Indonesia, rate of spread has been recorded to be up to 0.68 km per year. (Sheil & Padmanaba 2011)

FIELD OBSERVATIONS DURING CONTROL ACTIVITIES IN THE WET TROPICS

Surveillance

When searching for Cecropia in the field, staff have learnt to adopt three techniques to maximise detection success, namely; 1) look up into the canopy, searching for the unique leaf shape and the leaves’ silvery/white underside; 2) look ahead for the distinctive leaf scars on the stems; and 3) look down for the large, dry, silvery grey leaves on the ground. (See Figures 1, 2 and 3)

There is a distinct difference in the shape or habit of mature trees which have been exposed to significant natural disasters in north Queensland, with damaged plants coppicing (forming multiple stems) which eventually fuse, forming a stem diameter (dbh) greater than 100cm. (see Figure 2)

Aerial surveillance can be very effective when applied to Cecropia (Figure 1). The species height and distinctive large leaves that fill gaps in the canopy are traits that facilitate detection. A trial commissioned by Biosecurity Queensland achieved very high detection rates using manned and unmanned aerial vehicles (Bulstrode 2014). Results were supported by similar work undertaken by the Four Tropical Weeds program.

Although plants are readily detected from both air and ground, a significant obstacle has always been the ability to access and survey huge areas of land that are potentially infested. At present, all land within a 2 km radius of any mature female plants is routinely searched (Panetta et al. 2010). One of the major leanings has been to record the sex of plants prior to treatment and follow-up surveillance. In the past, the inconspicuous nature of flowers and fruit has resulted in the sex of plants not being recorded, leading to unnecessary search areas being created around plants that may not have the ability to produce seeds. Recording the sex of plants is also important when you enter the monitoring phase of a control program as this begins once the last reproductive female has been removed.

Management areas in north Queensland extend from urban areas deep into the World Heritage listed rainforests. There was initial concern that on-ground surveillance resources were being expended mostly in the more accessible areas first, with lower priority given to inaccessible areas. However, considering the species’ photoblastic seeds and the high attrition rates suffered by seedlings under shade, it may not be so important to search challenging terrain under in-tact rainforest canopies as first thought. Field experience suggests that the highest densities of Cecropia occur in urban or rural areas in disturbed remnant forest, with very little recruitment and few immature plants being found in in-tact forest. In fact, in areas where Cecropia has invaded natural areas following disturbance (eg. Cassowary Coast Regional Council area subjected to two cyclones in 2006 and 2011) where these areas have had time to recover (>3 years), aerial surveillance has achieved very high detection rates. For example, at Garradunga, 25 plants were detected from the air, and only two additional plants were detected when surveillance was repeated on foot. Another observation is that many plants were observed 48 from the air prior to reaching sexual maturity; this and the fact that plants are dioecious and require a certain density of male and female plants for successful pollination, may Page

suggest that aerial surveillance combined with on ground control might be enough to suppress recruitment. As for seed longevity and return rates, three properties (from Clifton Beach, Cairns and Garadunga) where multiple mature male and female plants were observed with strong seedling recruitment were surveyed and controlled annually with no recruitment observed after two to three years. This is consistent with research that suggests seed longevity is less than 2 years.

Control

Application of Vigilant® herbicide gel (aminopyralid and picloram) using a cut-stump technique) was initially considered best-practice. However, revisiting older control sites has found that plants with fused stems or stilted roots did not have the desired mortality rate. Since this was discovered, a combination of alternative techniques has been trialled and proven successful, such as stem-injection and frilling with Unimaz® (imazapyr) or basal-barking with Access® (triclopyr and picloram). The proximity of plants to watercourses and public access need to be considered when choosing an appropriate control technique. Remote plants present the biggest challenge for surveillance efforts and, the development of herbicide that can be applied aerially would be highly desirable.

REFERENCES

Csurhes, S.M. (2016). Invasive plant risk assessment, Mexican bean tree (Cecropia spp.), Department of Agriculture and Fisheries, Brisbane, Queensland 4001.

Conn, B.J, Hadiah, B.L. and Webber, B.L. (2012). The status of Cecropia (Urticaceae) introductions in Malesia: addressing the confusion. Blumea 57:136-143.

Santos, F. (2000). Growth and leaf demography of two Cecropia species. Revista Brasileira de Botânica. 23:10.1590.

Bulstrode, M. (2014). Trials to improve the detection of Cecropia spp. using unmanned aerial systems. James Cook University, Cairns, Queensland 4870.

Silander S.R. & Lugo A.E. (2017). Cecropia peltata, Yagrumo Hembra, Trumpet-Tree. Website https://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/cecropia/peltata.htm

Sheil D. & Padmanaba (2011). Innocent invaders? A preliminary assessment of Cecropia, an American tree, in Java. Plant Ecology & Diversity Vol 4: 2-3 Pages 279- 288.

Lowe S., Browne M., Boudjelas S. & De porter M. (2004) 100 of the world’s worst invasive alien species. A selection from the Global Invasive Species Database, 2nd edition. The Invasive Species Specialist Group, Auckland.

Panetta, D. F., Csurhes S., Markula A. and Hannan-Jones M. (2010). Predicting the cost of eradication for 41 Class 1 declared weeds in Queensland. Department of Employment, Economic Development and Innovation, GPO Box 46, Brisbane 4001, Australia. 49

Vázquez-Yanes, C. & Orozco-Segovia, A. (1993) Patterns of Seed Longevity and

Germination in the Tropical Rainforest. Annu. Rev. Ecol. Syst. Vol 24 Pages 69-87. Page

CONSERVING BLACK-THROATED FINCH HABITAT

Jaymie Rains NQ Dry Tropics, PO Box 1466, Townsville QLD 4810

INTRODUCTION

The Black-throated Finch is a small (to 12cm), sleek and stocky bird with a grey head, thick black bill, cinnamon-brown, with a conspicuous black bib on its throat. They are predominantly granivorous birds that devote most of their daily activity to feeding on fallen seeds of native and exotic grasses and herbaceous plants. Although favouring fallen seed they are known to pull free-standing seed heads to the ground in order to access the seed. They are also known to occasionally feed on insects.

Their habitat is broadly described as comprising of open grassy woodlands or forests, often dominated by eucalypts, melaleucas or acacias, where there is access to seeding grasses and water (Zann 1976, Garnett and Crowley 2000, Higgins et al 2006, Garnett 1993).

There are two subspecies; the northern (Poephila cincta atropygialis) and the southern (Poephila cincta cincta), which have different habitat requirements and are regarded as different species by the State and Federal governments.

The southern subspecies of the Black-throated Finch (BTF) (Poephila cincta cincta) has suffered a major range contraction since European settlement (NRA 2007, TSSC 2005) and is found across only a fraction of its former range. This contraction and resultant population decline is largely the basis for the southern subspecies being listed as Endangered under the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999 (EPBC Act, 1999) and Queensland Nature Conservation Act 1992 (NC Act, 1992).

The Townsville Coastal Plain is home to one of the largest known populations of the BTF (southern subspecies), which experts regard as critical to the long term conservation of the subspecies (Buosi 2009). Due to increasing threats in the Townsville region, there is urgent need for regional conservation planning and management to ensure that the BTF population survives (Vanderduys et al, 2016).

NQ Dry Tropics, a non-governmental not-for-profit natural resource management organisation, applied the Open Standards for the Practice of Conservation to create the Black-throated Finch Conservation Project. The BTF Conservation project worked with regional stakeholders in a collaborative process, establishing an integrated management program, focussed on allocating resources in priority areas where suitable habitat occurs and BTF is consistently recorded.

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METHODS The Protecting Biodiversity Program at NQ Dry Tropics implemented the internationally recognised Conservation Measures Partnership Open Standards for the Practice of Conservation (CMP 2017). This process follows a collaborative adaptive management framework of setting goals and priorities, developing strategies, taking action and measuring results of on-ground works.

With community consultation, key conservation assets, or targets, were identified. Through several workshops, the BTF habitat was identified as an asset and its viability or health was analysed in accordance with Queensland Herbarium ranking criteria (Department of the Environment and Energy 2017). Following viability analysis, threats to the health of the asset were identified and ranked in accordance with the Open Standards guidelines (CMP 2017). Actions and measurable objectives were developed to achieve the long-term conservation of the assets and practical monitoring indicators identified. At the conclusion of these workshops, the Black-throated Finch Conservation Project team developed an integrated management program focusing on the protection, maintenance and restoration of priority areas where substantial suitable BTF habitat occurs and BTF are consistently recorded.

The Project Manager and a consultant ecologist conducted rapid site assessments to determine the potential presence of BTF habitat and the presence of the species at potential project sites on the Townsville Coastal Plain. A combination of habitat modelling and on-site ground-truthing was used to determine the level of priority for project sites.

Projects were prioritised based on: 1) consistent presence of BTF populations; 2) presence of BTF habitat; and 3) willingness of landholders to participate in the project. As a result of the prioritisation process, four properties in the Townsville Coastal Plain were selected for the Black-throated Finch Conservation Project. Habitat management plans to support the populations of BTF were developed for each property, in consultation with the landholder. The management plans included recommendations for monitoring changes in habitat condition over time. The baseline condition of habitats was assessed and documented based on quantitative and qualitative data.

Using these habitat management plans, NQ Dry Tropics has entered into Land Management Agreements (LMA) with each of the four landholders. The LMAs provide funding for the landholders to undertake management actions that will improve the condition of the BTF habitat on their properties through a range of activities, especially fencing and weed management.

DISCUSSION

One of the major threats to BTF populations across the Townsville Coastal Plain is weed incursion. Weeds reduce the amount of available food for the birds and may force them to move elsewhere. The weeds not only crowd out the favoured food sources, they reduce roosting and nesting opportunities. Removing and reducing the impacts of weeds on BTF habitat through poisoning and extraction is one of the most efficient ways to preserve, 51 maintain and restore BTF habitat in this region. Page

The Black-throated Finch Conservation Project properties vary in size, location and usage. The smallest property is approximately 13 ha and has a usual stocking rate of three horses and one cow. Previous owners have grazed it more heavily leading to reduced grasses and increased pasture weeds, such as horehound (Mesosphaerum suaveolens) and spinyhead sida (Sida acuta), with increasing grader (Themeda quadrivalvis) and thatch grasses (Hyparrhenia rufa). There are minimal woody weeds, with only a few Chinee apple bushes (Ziziphus mauritiana). (See Images 1 and 2). Based on their LMA, the landholder will start to manage the weeds through spraying with broadleaf selective herbicides and spot application of Vigilant II™ and improved pasture management.

The next property at 230 ha has approximately 150 head of cattle. The landholder has actively managed the property for woody weeds for many years and is rightly proud of this work. However, the high stocking rate is impacting the grass population and is leading to increased herbaceous weeds, including horehound and snakeweed (Stachytapheta jamaicensis). The landholder will use integrated management techniques to tackle this, combining tractor slashing and spraying with broadleaf selective herbicides initially. (See Images 3 and 4).

The third property is 1400 ha, with a current low stocking rate and has only been under current ownership for a couple of years. The landholders are keen to manage the property well and are looking to completely change the previous grazing management regime. Paddocks are being subdivided and multiple waterpoints are being installed. The property shows evidence of previous heavy grazing. There are areas of thick woody weeds, including Chinee apple, lantana (Lantana camara) and rubber vine (Cryptostegia grandiflora) and many areas of reduced grasses and increased herbaceous weeds (horehound, spinyhead sida and snakeweed). The landholders will be slashing and spraying weeds with broadleaf selective herbicides to reduce their impacts. (See Images 5 and 6).

The fourth and largest property is 7000 ha and has been in the same grazing family for more than 60 years. The grazing management is slowly changing as the younger generation learns new methods. Previous incursions of woody weeds have exceeded the landholder’s efforts to control them and will be removed using project funding. These Chinee apples, lantana and rubber vine plants have formed dense thickets. Machinery removal will allow the landholder to sow pasture grasses that are also suitable for BTF use. There are also increasing herbaceous and grassy weeds across the property, including heavy loads of Wynn cassia (Chamaecrista rotundifolia). (See Images 7, 8, 9 and 10).

Each of the properties will have soil samples taken and testing performed to determine if any amelioration will assist with the reduction in weed loads and an increase in grasses. It will be a delicate balance to ensure that rapid changes in condition don’t occur that might adversely affect the BTFs.

As of September 2017, the LMAs have only been in place for a couple of months. Works are expected to be well underway by December and any updates on the progress of the properties will be presented during the oral presentation.

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ACKNOWLEDGEMENTS

Thank you to my Protecting Biodiversity team colleagues; Peter Buosi; and the Black- throated Finch Recovery Team; and of course, the four landholders doing all the on- ground works.

REFERENCES

Buosi, P. 2009. Distribution of Potential Nesting Habitat of the Black-throated Finch (Poephila cincta cincta) in the Townsville Local Government Area – A Predictive Model. Townsville, Australia. CMP (2017) http://cmp-openstandards.org/download-os/

Environment Protection and Biodiversity Conservation Act 1999, https://www.legislation.gov.au/Details/C2016C00777, (accessed 20 September 2017).

Department of the Environment and Energy (2017) Guidelines for nominating and assessing the eligibility for listing of ecological communities as threatened according to the Environment Protection and Biodiversity Conservation Act 1999 and the EPBC Regulations 2000, http://www.environment.gov.au/system/files/pages/d72dfd1a-f0d8- 4699-8d43-5d95bbb02428/files/guidelines-ecological-communities.pdf

Garnett, S.T., ed. (1993). Threatened and Extinct Birds of Australia. Royal Australasian Ornithologists Union Report 82 2nd (corrected) Edition. Melbourne: Royal Australian Ornithology Union and Canberra: Australian National Parks and Wildlife Service.

Garnett, S.T. & G.M. Crowley (2000). The Action Plan for Australian Birds 2000. [Online]. Canberra, ACT: Environment Australia and Birds Australia. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/action/birds200 0/index.html

Higgins, P.J., J.M. Peter & S.J. Cowling, eds. (2006. Boatbill to Starlings. In: Handbook of Australian, New Zealand and Antarctic Birds. 7. Melbourne: Oxford University Press.

Koch, P.J., King, B. and Rains, J.M. (2016), Conservation Action Plan for the Burdekin Plain and Adjacent Ranges Subregion. Summary report produced by Greening Australia for NQ Dry Tropics. NQ Dry Tropics, Townsville, Queensland.

Natural Resource Assessment Environmental Consultants (NRA) (2007). Survey and Assessment of the Black-throated Finch (Poephila cincta cincta) at the Chisholm Trail Rural Residential Development, Townsville. Unpublished report prepared for the Department of Environment and Water Resources.

NRA (2012). Review of Black-throated Finch Population Data for the Townsville Region. Report prepared by NRA Environmental Consultants for NQ Dry Tropics on behalf of the BTF Trust.

NRA (2017), Assessment and Management Advice Pertaining to the Black-Throated Finch (Poephila cincta cincta) and “Property Name”, R03 (final), Prepared by NRA Environmental Consultants for NQ Dry Tropics, 1 June 2017. (“Property Name” refers to all four properties – identifying features have been removed due to privacy requests by the 53 landholders.) Page

Nature Conservation Act 1992, https://www.legislation.qld.gov.au/LEGISLTN/CURRENT/N/NatureConA92.pdf, (accessed 20 September 2017).

Rains, J. and King, B. (2016) Black-throated Finch Project Plan. NQ Dry Tropics, Townsville.

Threatened Species Scientific Committee (2005). ‘Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)’ http://www.environment.gov.au/node/16484

Vanderduys, E.P., Reside, A.E., Grice, A., Rechetelo, J. (2016) Addressing Potential Cumulative Impacts of Development on Threatened Species: The Case of the Endangered Black-Throated Finch. PLoS ONE 11(3): e0148485. doi:10.1371/journal.pone.0148485 Zann, R. (1976). Distribution, status and breeding of Black-throated Finches Poephila cincta in northern Queensland. Emu. 76:201-206.

IMAGES

Image 1. Property One, with stock and Image 2. Property One, with stock and pasture weeds (horehound; spinyhead sida small Chinee apple and snakeweed)

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Image 3. Property Two, with pasture weeds Image 4. Property Two, with Peter Buosi Page

(snakeweed and spinyhead sida) assessing the pasture condition.

Image 5. Property Three, with two Black- Image 6. Property Three, with new gates throated Finches in rubber vine. and fencing installed to reduce paddock size and allow for improved weed and pasture management.

Image 7. Property Four, showing the heavy Image 8. Property Four, showing a BTF Wynn cassia load. nest in a Chinee apple bush; not a usual site for a nest.

Image 9. Property Four, showing a habitat Image 10. Property Four, showing results

assessment transect through lantana and of initial dozer removal of Chinee apple and

other weeds. lantana thickets. 55

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LANTANA CONTROL ON EASTERN TORRES STRAIT ISLANDS USING SPLATTER GUN TECHNIQUE.

Janine Buist2, John Lynn1, Aaron Bon1 and Boggo Gela1 1Torres Strait Regional Authority. 2Land and Sea Management Unit. Level 1 Torres Strait Haus, 46 Victoria Parade, Thursday Island, Queensland, Australia

ABSTRACT (SUMMARY)

Erub (Darnley Island) and Mer (Murray Island) are remote islands located in the eastern Torres Strait and are traditionally owned. Torres Strait Regional Authority (TSRA) work collaboratively with traditional owners to address strategic ecological management for the region, detailed management plans are developed for each individual island. Lantana (Lantana camara) has likely been present on these islands since World War II, when it was introduced from Cairns, (Clarke and Day 2005). The rich volcanic soil and vegetation disturbance on these islands has facilitated lantana’s spread (Freebody 2006). The island communities have had little capacity to deal with large lantana infestations prior to the establishment of the Land and Sea Management Unit (LSMU) Ranger Program in 2009. Extensive consultation was necessary through the Erubam Le Traditional Land and Sea Owners (Torres Strait Islanders) Corporation Registered Native Title Body Corporate (RNTBC), Mer Ged Kem Le Corporation and Traditional Owners, prior to any lantana control project works being carried out.

The TSRA rangers commenced on ground lantana control works on Erub during March 2015. Superior control results were obtained between the January and May periods when high soil moisture stimulated plant growth. Splatter gun methodology was adopted as the best method to control lantana as it permitted rangers to access rugged and remote areas that would not have been possible using other conventional control methods. The lantana control program has expanded to include Mer which also has large infestations.

Keywords: Lantana control, Weed of National Significance, Torres Strait, splatter gun, drone, Traditional Owners

INTRODUCTION Lantana is an identified Weed of National Significance (WoNS) and is considered to be one of the ten worst weeds worldwide (DNRM 2004). Lantana has impacted the remote islands of the Torres Strait, most significantly on Mer and Erub. Special significance is assigned to these Islands, due to both the uniqueness of the volcanic landscape, and the rarity of basaltic grassland types prevalent on these islands in the broader bioregional area Stanton and Fell (2008). On Erub lantana usually forms dense thickets on the interface between vine thickets and grasslands. On Erub grassland habitat represents 56% of the total species diversity and the Near-Threatened grass Apluda mutica is known to occur in this habitat and is likely threatened by lantana invasion (3D Environmental 2013a). On Mer the habitat is strongly influence by a long term established permaculture with traditional food trees and as such, holds cultural significance by providing a record of 56 traditional agricultural practice in the eastern Torres Strait Islands (3D Environmental 2013b). Page

Climate change will likely provide invasive plants, such as Lantana, a significant advantage creating the potential for dominance, Drake et al (2005). On Erub and Mer, the implications of large-scale lantana infestations on fire behaviour at rainforest margins are significant. Lantana’s ability to suppress cool fires and burn fiercely under severe conditions can promote wild fire intensity, resulting in serious damage to rainforest margins, which in turn and can lead to a permanent loss of habitat, by its ability to then repeatedly invade damaged areas. Uncontrolled fires in the grassland areas threatened the adjacent vine forest which contain vulnerable species including the Eclectus Parrot Eclectus roratus and Papuan Sheathtail Bat Saccolaimus mixtus on Erub and threatened species such as the emerald monitor Varanus prasinus and slender chained gecko Lepidodactylus pumilus on Mer (3D Environmental 2012).

Land management activities, including weed control, occur within a complex administrative landscape with shared responsibilities across a number of stakeholder parties. TSRA works in conjunction with Torres Strait Island Regional Council (TSIRC), Traditional Owners, Torres Strait Invasive Species Advisory Group members (TSISAG) and research scientists, to deliver on the ground control works. Weed control works for lantana are undertaken in accordance with the respective traditional owner endorsed plans of management for each island. Community are engaged in the development of the plans and are informed via community notices and meetings, when works are scheduled. Traditional Owner skills and knowledge including; weed control, landscape management and the use of fire are recorded in the Traditional Ecological Knowledge database.

MATERIALS AND METHODS Strategic lantana control work was initiated on Erub in March 2015 and Mer in March 2016, with the assistance of TSRA Rangers from the Torres Strait. This work could only proceed following extensive consultation with the Erubam Le Traditional Land and Sea Owners (Torres Strait Islanders) Corporation Registered Native Title Body Corporate (RNTBC) and Traditional Owners. Consultation was facilitated through community meetings that were conducted in late dry season of 2014. Formal approval for any major project activity undertaken by the TSRA Rangers is required from the relevant Island community’s RNTBC. Following broad consultation this project received strong support from both the RNTBC and community as they had observed the substantial increase of this weed over the past two decades. A major concern to the community residents was ensuring that the herbicide TSRA was using did not have a long term residual impact or produce any negative impacts to marine reefs or plantation food resources. It was therefore essential that community consultation was carried out in order for these concerns to be addressed. The splatter gun methodology was adopted for this lantana control work as it was identified as best practice, Torres Strait Regional Authority (2007). The splatter gun (or gas gun) control technique involves the low volume, high concentration application of herbicide to lantana foliage. This technique is particularly useful in areas of difficult access or sensitive vegetation because the tool is easily portable, (approximately 6 KG and contained in a backpack) and causes limited off target damage. The splatter gun method utilises a gas powered, drench style gun that can reach target plants as far as 6-10 m distance. Glyphosate herbicide was mixed with water at a rate of 9:1. Surfactant was added to the glyphosate / water mix at a rate of 2 ml / L to increase effectiveness. The total capacity of 57 the herbicide knapsack is 5 L and the knapsack is secured in a backpack which also houses the gas canister and regulator. The herbicide mix is applied in dosages of Page

approximately 10 ml - 20 ml delivered in one metre spaced lines over the lantana. A marker dye can be added to the herbicide mix to delineate areas sprayed and prevent accidental double application of plants. Drone footage was acquired on Mer by a Phantom 3 Professional. All mapping flights were carried out via automated flight using the Map Pilot for iOS app at a speed of 6.4m/s, an altitude of 40m, and with 75% sidelap and frontlap between images. This combination of camera and altitude resulted in a 1.7cm on-ground pixel size and gap-free mapping, with potential to use photogrammetry approaches for 3D scene reconstruction.

RESULTS Results show a marked decrease in lantana on Erub of between 30 and 40%. The lantana control program was expanded to include Mer which also has large infestations that have been reduced by approximately 20% since control works were implemented (figures 1 and 2). The use of the gun splatter technique has proven to be a cost effective management technique delivering positive reduction rates of lantana, during the weed control period. The application method was well suited to the remote location and the equipment will continue to be used for ongoing control activities.

The use of the splatter gun methodology to control lantana, allowed rangers to access rugged and remote areas on Erub and Mer, which would not have been possible to do using other conventional control methods. Superior control results are obtained between the January and May periods when high soil moisture stimulates plant growth. The splatter gun methodology permits rangers to access rugged and remote areas that would not have been possible using other conventional control methods. The lantana perishes within a period of four to six weeks following herbicide application and control programs are implemented at this time. The use of drone footage to assess the impacts of lantana control has provided another tool to measure the effectives of the control measures and was found to be highly useful in negating the difficulties in accessing areas in difficult terrain.

Rangers have observed significant native vegetation regrowth in the areas previously heavily infested with lantana. Regaining important native grassland habitat for native birds such as buff-banded rail Gallirallus philippensis, pale-vented bush hen Amaurornis moluccana and the red-chested quails Turnix pyrrhothorax. Meriam people are renowned throughout the Torres Strait as gardeners and these grasslands were cultivated for gardening, treating the lantana on Mer has facilitated access to traditional gardening sites and other cultural sites that were otherwise impossible for most people to access.

DISCUSSION

Lantana control has been identified as a very high priority for these islands in the Torres Strait Region Biosecurity Plan (2017 - 2022). Impacts of lantana infestations include a reduction in fresh water quality, erosion, habitat quality, viable land use, risks to cultural sites and access to culturally significant areas. Financial implications of control are large, but the cost of inaction far greater. Ongoing implementation of the Land and Sea

Management Strategy for Torres Strait 2016-2036 is subject to ongoing funding of the 58

TSRA Ranger Program. Focused funding for managing lantana by the Queensland Regional Natural Resource Management Investment Program, has enabled an escalation

of management actions and weed control over the last three years. Page

Achieving community and Traditional Owners support is fundamental to the long-term success of this weed program. It is anticipated to take 10 years to reduce the large lantana infestations on both Mer and Erub to manageable levels. New technologies, including drones, will be adopted to assist in mapping and monitoring work in the future. The positive implementation of the splatter gun technique will have broader applications across the Torres Strait and guide future management plans. Traditional Ecological Knowledge in conjunction with emerging technologies will be integrated into the ecological and cultural management of invasive species.

ACKNOWLEDGMENTS

We would like to thank both the Erubam Le land and sea owners and Mer Ged Kem Le Corporation RNTBCs for their ongoing support to undertake these projects. The Department of Prime Minister and Cabinet for funding of the ranger program and the Queensland Regional Natural Resource Management Investment Program, for funding addressing emerging invasive species and biosecurity threats in Torres Strait.

REFERENCES 3D Environmental (2013a,b). Profile for Management of the habitats and related ecological and cultural resource values of Erub Island. Prepared for the Torres Strait Regional Authority 3D Environmental (2012). Profile for Ecological Fire Management of Erub Island. Prepared for the Torres Strait Regional Authority

Andrew Clarke and Michael Day, Report on Lantana camara infestations in the Torres Strait and possible options for control, Weeds of National Significance (WONS), May 2005.

Drake BG, Hughes L, Johnson EA, Seibel BA, Cochrane MA, Fabry VJ, Rasse D and Hannah L (2005) Synergistic Effects. In: TE Lovejoy and L Hannah (eds) Climate Change and Biodiversity. Yale University Press, New Haven, London, pp.296–316.

Freebody K (2006), Report to the Torres Strait Regional Authority in relation to the project; Re-establishment of stable landscapes on Darnley Murry and Yorke Islands.

Stanton JP and Fell DG (2008). The rainforests of Cape York Peninsula. CRC Research Monograph.

Torres Strait Regional Authority (2007) “Best practice for lantana eradication”, NLP Community Support Program. www.tsra.gov.au/__data/assets/pdf.../best20practice20for20lantana20eradication.pdf

Torres Strait Regional Authority (2016) “The Land and Sea Management Strategy for Torres Strait 2016-2036” www.tsra.gov.au/.../the-land-and-sea-management-strategy- for-torres-strait-2016-203 59 Torres Strait Regional Authority (2017) Torres Strait Regional Biosecurity Plan and Torres Strait Island Biosecurity Action Plans 2017-2022 in press Page

Weeds of National Significance, Lantana Control Manual, Qld DNRM & E, 2004.

Figure 1. Lantana Control activities on Erub Island January to March 2015 - 2017

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Figure 2. Lantana Control activities on Mer Island January to March 2017 Page

BRIDGING BARRIERS THROUGH PARTNERSHIPS FOR WEED MANAGEMENT ON CAPE YORK

Peta-Marie Standley1, Vicki Wundersitz1, Wunthulpu Aboriginal Land Trust.

1Cape York NRM 47-49 Maunds Road Atherton QLD 4883.

ABSTRACT

Cape York is a complex region, covering 16 million hectares and containing both a diversity of landscapes and a diversity of people. The region has a rich history and is a living cultural landscape which faces some unique challenges. The challenges for managing weeds include limited baseline monitoring data; the tyranny of large distances; and high costs to coordinate and deliver landscape scale containment of invasive plants and animals.

The key elements of a successful weed management program to care for the natural environment of Cape York are knowledge, coordination and partnerships. Partnerships are perhaps the most essential. By working with Traditional Owners and non-indigenous land managers to deliver collaborative management of weeds, positive environmental and social outcomes can be achieved at the same time. Our learning’s show the challenge of managing and/or reducing the impact of priority weeds is best addressed by supporting local leaders with local knowledge to deliver on-ground actions efficiently, while exchanging capacity and knowledge with other groups.

One such example is the approach taken to address an established infestation of Rubber vine (Cryptostegia grandiflora) along the Lukin River, a tributary of the Coleman River north of the containment line near Musgrave. A multi-stakeholder project was developed to contain and reduce the further spread of established rubber vine through control works and mapping of treated areas. A strong legacy has been established with Traditional Owners Wunthulpu Aboriginal Land Trust and station owners of Yarraden Station working in partnership to champion land management in their “country”.

Keywords: Cape York, Lukin River, Wunthulpu Aboriginal Land Trust, Rubber vine, Cape York NRM

INTRODUCTION

Region and challenge 61

The Cape York region is a complex region covering 16 million hectares and contains both

diversity of landscapes and diversity of people. The region contains a third of Page

Queensland’s coastline; 16 complete river basins; has over 300 threatened species; as well as one third of the Great Barrier Reef. The region also has a rich historical and living cultural landscape with about 45 distinct Aboriginal languages with several hundred dialects, a strong cattle culture and an increasingly thriving horticultural sector.

Weeds and pest animals have significant landscape scale economic, environmental, cultural heritage and social impacts. Introduced species have the potential to reduce primary industry productivity and profitability; alter ecosystem function; impact on culture and limit the long-term sustainability of Cape York’s agricultural and natural resources. The region is also challenged with limited baseline monitoring data, the tyranny of large distances and high costs to coordinate and deliver landscape scale management of invasive plants and animals.

Celebrating partnerships

The key elements of a successful weed management program to care for the natural environment of Cape York are knowledge, coordination and partnerships. Partnerships are perhaps the most essential. By working with Traditional Owners and non-indigenous land managers to deliver collaborative management of weeds, positive environmental and social outcomes can be achieved at the same time. Our learning’s show the challenge of managing and/or reducing the impact of priority weeds is best addressed by supporting local leaders with local knowledge to deliver on-ground actions efficiently, while exchanging capacity and knowledge with other groups. .

The Cape York NRM Plan has been developed through engagement and consultation with the Cape York community and the plan details identified pathways and targets for working towards achieving agreed natural resource management outcomes for the region. Importantly, this approach of engagement and partnerships is driven by community voices and on-ground projects happening in Cape York.

The delivery model of encouraging coordinated and localised strategic control of pests and weeds has been hailed as a success as it builds and increases legacy capacity for pest and weed management in Cape York at local scale. The process is always adapting to better suit the real-world needs of the people and ecosystems of Cape York country.

Achievements through partnerships

Working on country with Traditional Owners and non- Indigenous land managers has a wide range of benefits and is delivery successful results. Some positive outcomes include enhanced capacity and weed management skills and improved weed surveillance/ control data for the region.. Other benefits include an improved resilience of several priority landscapes through partnerships. Some examples of these projects includes: • Reduced threat to native vegetation through control of Rubber vine and surveillance along the Lukin River containment line in central Cape York with Wunthulpu Aboriginal Land Trust, Yarraden Station and Astrea Station • Monitoring and control of lantana at Lava Hill with Wunthulpu Aboriginal Land Trust

• Northern Peninsula Area Regional Council Apudthama Land and Sea Rangers 62

containing and reducing the further spread of Gamba grass in the Northern Peninsula Area Page

• Pormpuraaw Aboriginal Shire Council Rangers control of Hymenachne on the west coast • Hopevale Congress Rangers and Cape York Weeds and Feral Animals Inc control and surveillance of Pond Apple at South Cape Bedford

Case study ‘Containing and reducing the further spread of established rubber vine north of the containment line near Musgrave – Lukin River’

Cape York is a bridge between Australia and Papua New Guinea and is unique in that it is threatened by weeds from the north and the south. Rubber vine (Cryptostegia grandiflora) is an invasive climbing vine or shrub that smothers riparian vegetation and forms dense thickets along rivers. Rubber vine is category 3 restricted matter (Biosecurity Act 2014) and a Weed of National Significance. There are several national management zones and the boundary of the northern most containment area within Queensland is along the road from Musgrave to Pormpuraaw. An established infestation occurs along the Lukin River, a tributary of the Coleman River north of the containment line. This infestation was identified for eradication before it spread further north and damaged more riparian areas.

Figure 1. Basal bark control of rubbervine on the Lukin River

A multi-stakeholder project was launched, ‘To contain and reduce the further spread of 63 established rubber vine north of the containment line near Musgrave – Lukin River through control works and mapping of treated areas’. The project aimed to build technical capacity Page

and skills to survey, safely control and monitor the infestation of Rubber vine by teams from the Ayapathu Rangers along with the Wunthulpu Aboriginal Land Trust and the Yarraden station land managers.

The key aim was to control Rubber vine and attempt further containment at the established Lukin River containment area. The main objectives of the project were to prioritise any new infestation in the northern region of the Lukin and to control existing Rubber Vine along the Lukin River. Strategic control was achieved by targeting the source of the infestation up river and moving systematically down river. Importantly the project aimed to establish an ongoing legacy by ensuring local Traditional Owners are empowered with the resources, technical expertise, project feedback and leadership in order to champion land management in their country. Detailed spatial data for this project was collected using iPads with the Fulcrum app installed. Teams have partnered to work on ground along the containment line through funding from the Queensland government NRM Investment from 2014 to now.

Figure 4. Rubbervine control works on the Lukin River (left) and rubbervine imapct on native vegetation (right)

The partnerships created and maintained in delivering this project have proved to be one the most important and enduring outcomes The working partnership of Ayapathu

Rangers, Cape York NRM and Yarraden Station “is required to ensure local capacity, 64

ongoing legacy, Traditional Owner approval, empowerment and engagement, property access and funding, technical advice, support and data storage.” (pers. comm from consultant to Wunthulpu). The Ayaputhu Rangers report that through using Fulcrum app Page

“In 15-20 years of work, first time we have been able to assess the data in the field around the campfire and get an instant result in 10 minutes.”

The Rubber vine containment line (Lukin River) has now been completely traversed to the Astrea Station border and rubber vine effectively controlled through this partnership during 2013, 2014, and in 2015/16 the partnership began to work their way back up the smaller order streams.

Future

Weed management programs across the region demonstrate the importance of ongoing partnerships between Cape York land managers including Traditional Owners, non- Indigenous and pastoral land managers as well as community groups. The proven benefits of partnerships in the Cape York NRM region deliver weed management outcomes but also results in improved local capacity and improved data for the region in relation to weed surveillance and control.

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BROAD SCALE INTRODUCTION OF CROWN ROT IN WEEDY SPOROBOLUS GRASSES (GIANT RAT’S TAIL AND GIANT PARRAMATTA GRASS)

Jeremy Bradley and Cathy Eggert Beechwood Biological Solutions, 83 Capararos Road, Beechwood, NSW 2446.

ABSTRACT The native saprophytic fungus Nigrospora oryzae is associated with crown rot in the Weedy Sporobolus Grasses. Funding cuts to the NSW Department of Primary Industries’ program to develop a commercial Nigrospora product inspired a pair of biological farmers to take on the task. With a strong background in soil biology and practical biological farming skills, the couple developed a method of cultivating a concentrate of the fungus. Marketed as “Parra Trooper”, the product is applied as a spray. The entire organism is used and fragments of fungal hyphae continue their growth when applied during favourable weather conditions. Crown rot has reduced Giant Parramatta grass infestations to levels below economic concern within a couple of years at trial sites in NSW. In Queensland, results in Giant Parramatta grass and Giant rat’s tail grass are promising. Results from trials throughout Queensland including the Gympie region (Southeast Qld) and the Atherton Tableland (Far north Queensland) are presented. Keywords: Nigrospora oryzae, Weedy Sporobolus Grasses, Giant rat’s tail grass (GRT), Giant Parramatta grass (GPG), biological control, Parra Trooper.

INTRODUCTION The Weedy Sporobolus Grasses, including giant Parramatta grass, Sporobolus fertilis (GPG) and giant rat’s tail grass, S. pyramidalis and S. natalensis (GRT) have the potential to invade 223 million ha nationally, including 60% of Queensland (Bray and Officer 2007).

The native soil fungus, Nigrospora oryzae is associated with a necrotic crown rot in GPG (Lawrie 2011). However, Fletcher and Leemon (2015) concluded that, based on results from field and pot trials, no pathogenic relationship exists between N. oryzae and GRT.

Parra Trooper is a novel N. oryzae inoculum, and preliminary results from inoculation trials of GRT with Parra Trooper are presented.

Background

N. oryzae was first observed to be pathogenic to Sporobolus spp. in the Orara valley, NSW, in 2000 (Officer 2013). After appropriate biosecurity investigations into off-target and health implications of the organism, NSW Department of Primary Industries (DPI) began trials with spores harvested from laboratory-grown cultures and by transplanting diseased plants into healthy stands of GPG. Both methods initiated crown rot in GPG 66 (Officer et al. 2012).

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Pastoralists in Northern NSW were encouraged to spread the crown rot disease by transplanting diseased plants and DPI scientists began developing a commercial application. Limited funding slowed the research and eventually forced the abandonment of the DPI’s product development program (Officer, pers. comm.).

Some experimental work was done with N. oryzae in GRT and crown rot occurred at several locations in NSW (Officer, pers. comm.). Compared with GPG, GRT appeared more resistant to crown rot and more difficult to detect crown rot when it was present. Crown-rot affected GRT does not display the seasonal orange ‘flare’ characteristic of diseased GPG plants.

The authors combined their experience in the broad scale inoculation of farms with beneficial soil fungi with innovative methods of mass-producing N. oryzae to produce Parra Trooper, a concentrated source of N. oryzae. Positive results in most soil types have been experienced over a wide area of Northern NSW and SE Qld in GPG and reductions in GRT cover and vigour have been reported across a wide area (Clayton, Plowman pers. comm.).

Inoculation with Parra Trooper Parra Trooper is a live culture of N. oryzae growing on a pre-sterilised substrate. The spores and hyphae are washed from the substrate by aggressive agitation and rinsing prior to filtering and dilution for use as a spray. Parra Trooper, when applied at the recommended rate, distributes >108 spores/ha. Fragments of N. oryzae hyphae may also propagate the fungus but their survival is dependent on favourable weather conditions for their establishment.

N. oryzae in the field N. oryzae is a common saprophytic fungus that is found throughout the potential range of Sporobolus spp. N. oryzae spores are quite hardy and will survive extreme conditions. This fast-growing fungus produces spores rapidly in the presence of sufficient food and moisture. Commonly saprophytic, N. oryzae also behaves as an endophyte in some host species.

METHODS

Atherton Tableland trials (FNQ)

Mareeba Shire Council Senior Land Protection Officer, Sid Clayton, sprayed several GRT- infested sites in the Mareeba district with Parra Trooper at the recommended rate (i.e. >108 spores/ha) in early 2017 in wet weather, followed by a dry period from April through to July 2017. The same equipment was used at each site.

Mary Valley trials (SEQ)

In the Mary Valley (Gympie Region) of SE Queensland, Hinterland Helper and Rural Services’ Christopher Plowman, applied Parra Trooper over a period of around six months from November 2016. Apart from March 2017, this period was unseasonably dry. 67

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Sampling and counting spores of N. oryzae

To assess the success of N. oryzae inoculation the authors developed a rapid and inexpensive method of quantifying the relative success of inoculation.

Field sampling Along approximately 100 m transects, within the treated area and an adjacent untreated area, individual tillers were removed from tussocks at intervals of ten paces. Samples were trimmed to 50 mm to remove seeds and excess leaf.

Sample preparation The sample tillers were air dried. As most of the spores are located within 50 mm of the crown of the tiller (Bradley, pers. obs.), sub-sample tillers, including such deteriorated old leaf as may be attached to the tiller, were randomly drawn from the sample and trimmed to remove roots and top growth. This sub-sample was cut into 10-15 mm pieces and mixed. 1 g of the sample was added to 250 ml of distilled water and blended on medium speed for 30 seconds. The liquid was strained through a sieve (500 um) and one drop of this liquid was placed on a microscope slide and covered with a 24 x 24 mm cover slip.

Spore counts Spores of N. oryzae are easily identifiable due to their large size (13-15 um), dark colour, elliptical shape and a distinctive conidiophore. The spores are readily seen at 100x magnification. The spore count of each slide was recorded and three or four replicates were counted per site (refer to Table 1).

RESULTS

Background levels of N. oryzae spores were detected in all control areas adjacent to GRT trial sites.

Atherton Tableland trials (FNQ)

Sites were sampled in July 2017. The results are presented as ‘pairs’ of treated and untreated transects from adjacent locations. Wetherby Station had three treated sites but only one control. Fassio Rd and Emu Creek treatment areas were unpaired and the untreated Goodsell site is not paired with a treatment (Table 1, Figure 1).

There was an apparent loss of health and vigour in GRT in all the treated areas (Figures 2,3). Higher numbers of N. oryzae spores were counted in the treated areas compared with the control areas.

Mary Valley trials (SEQ)

Visually, the results range from advanced necrosis to no apparent impact (Figures 4,5). The Baranballi site had no control sample as the entire property was treated. Baranballi was treated in late summer when the soil was relatively dry. GRT plants in the pig paddock appeared stressed but returned a nil N. oryzae spore count. Sites were sampled in July 2017.

68 All the inoculated areas, except the Baranballi pig paddock, exhibited spore counts above local background levels of N. oryzae. Page

Table 1. N. oryzae spore counts from GRT in Queensland (sampled 4/7/17 – 25/7/17). Sampling site Treatment Spore count 1 2 3 4 mean

Atherton Tableland Wetherby Platypus control 0 0 0 1 0.25 Wetherby Bump Parra Trooper 1 3 3 2 2.25 Wetherby RRR Parra Trooper 2 2 1 1 1.50 Wetherby Anthill Parra Trooper 1 3 2 7 3.25 Gallo Control 1 2 3 3 2.25 Gallo Parra Trooper 1 4 2 8 3.75 Cardillo Control 0 1 0 - 0.33 Cardillo Parra Trooper 2 3 2 - 2.33 Goodsell Control 1 0 1 0 0.50 Fasio Rd Parra Trooper 1 2 3 2 2.00 Lavis Control 0 1 1 1 0.75 Lavis Parra Trooper 11 3 4 3 5.25 Kingsley Control 4 2 4 - 3.33 Kingsley Parra Trooper 17 12 14 - 14.33 Emu Creek Parra Trooper 13 11 9 7 10.00

Mary Valley Oakwood 1 Control 2 3 1 0 1.50 Oakwood 1 Parra-Trooper 7 7 13 10 9.25 Oakwood 2 Control 2 4 2 3 2.75 Oakwood 2 Parra-Trooper 5 8 7 5 6.25 Krucks Rd Control 2 6 6 5 4.75 Krucks Rd Parra-Trooper 6 10 15 24 13.75 Baranballi sheep Parra-Trooper 3 7 2 5 4.25 Baranballi cow Parra-Trooper 2 4 5 4 3.75 Baranballi pig Parra-Trooper 0 0 0 0 0.00

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Figure 5. Mean count of N. oryzae spores per slide in untreated sites and sites treated with Parra Trooper.

Excluding the unpaired data and pairing Wetherby Platypus with Wetherby RRR (the lowest spore count for a treated area on this farm), a significant difference (95% confidence limit; student’s t-test) is indicated between the background level of N. oryzae and the level of N.oryzae in the treatment areas. It should be noted that this calculation excluded the Barranballi pig paddock which, whilst treated, returned a zero result.

Figure 6Cardlillo untreated (left) and treated (right). DISCUSSION

Early results, from the limited data presented, indicate the application of Parra Trooper has raised the level of N.oryzae and there are encouraging instances of necrosis in GRT that has been treated with Parra Trooper. More data is required to determine the efficacy of the product to initiate crown rot or, if that condition has initiated, how long it will persist.

However, the data does show that a quantitative methodology for field assessment of the presence and relative density of N. oryzae can be performed cheaply and efficiently and 70 that inoculation with Parra Trooper appears to increase the population of N. oryzae.

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Figure 7. GRT crown rot, Oakwood (left) and GRT crown rot detail, Oakwood (right)

NOTE

Parra Trooper is an unregistered product and the authors are negotiating with the APVMA towards registration.

ACKNOWLEDGEMENTS

David Officer, Sid Clayton, Christopher Plowman and many landholders in the Mareeba and Mary Valley areas assisted with these trials.

REFERENCES

Bray, S. and Officer, D. (2007). Weedy Sporobolus Grasses Best Practice Manual. 3rd Edn. Queensland Department of Primary Industries and Fisheries, Brisbane.

Fletcher, G.J. and Leemon, D. (2015). Biological control of Giant Rat’s Tail grass utilising Nigrospora oryzae. Meat and Livestock Australia Ltd, North Sydney.

Lawrie, A.C. (2011). Using the Fungus Nigrospora oryzae for the Biological Control of Giant Parramatta Grass. Rural Industries Research and Development Corporation, Canberra.

Officer, D., Ramasamy, S. and Lawrie, A.C. (2012). Effect of season on the efficacy of artificial inoculation of Nigrospora oryzae in Sporobolus fertilis. Eighteenth Australasian Weeds Conference. pp. 142-145.

Officer, D. (2013). Rotting to the crown: How a local fungus is controlling an introduced weed. Issues Magazine. 105. December 2013.

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BIOLOGICAL CONTROL OF PARTHENIUM: PROGRESS ON THE REDISTRIBUTION OF ESTABLISHED AGENTS TO SOUTHERN QUEENSLAND

J.T. Callander1, B. Shi1, S. Raghu2 and K. Dhileepan1 1Biosecurity Queensland, Department of Agriculture and Fisheries, EcoSciences Precinct, GPO Box 267, Brisbane, Qld 4001, Australia. 2 CSIRO, GPO Box 2583, Brisbane, Qld 4001, Australia.

ABSTRACT

Parthenium (Parthenium hysterophorus L.), a serious weed of grazing areas in central Queensland (Qld) and a Weed of National Significance in Australia, has spread into parts of southern Qld. The isolated nature of the southern Qld infestations, probably resulting from the movement of contaminated stock feed, livestock and machinery, has meant many of the effective biological control agents established in core infested areas of central Qld have not extended their distribution at the same pace as the weed. As a result, a program to redistribute these agents from central Qld to southern Qld was initiated. The seed- feeding weevil (Smicronyx lutulentus Dietz), the stem-boring weevil (Listronotus setosipennis (Hustache), and the root-boring moth (Carmenta nr. ithacae Beutenmuller), the winter rust (Puccinia abrupta var. partheniicola Dietel & Holway), and the summer rust (Puccinia xanthii var. parthenii-hysterophorae Seier, Evans & Romero) were prioritised for redistribution. Since late 2015, prioritised agents have either been bulk collected from central Qld, or reared in glasshouse facilities in Brisbane, and released at 19 sites across 10 geographically isolated areas in southern Qld. Periodic surveys of release sites have indicated strong evidence of establishment of the winter rust and the Smicronyx weevil at most of the sites and preliminary signs of establishment of the summer rust and the Listronotus weevil at a few sites. Redistribution of field-collected and glasshouse-reared agents and monitoring of their establishment status in the field will continue over the next year.

Keywords: Parthenium hysterophorus, biological control, redistribution, Queensland

INTRODUCTION

Parthenium hysterophorus L. (Asteraceae) is a noxious weed of grazing areas in Queensland (Qld), and a Weed of National Significance in Australia (Dhileepan and McFadyen 2012). The weed is estimated to reduce grazing land and pasture production, annually by over $16.5 million dollars (AUD) (Chippendale and Panetta 1994). Biological control of parthenium in Australia was first initiated in the late 1970s.

Eleven agents have since been released in core parthenium infested areas of central and northern Qld. These include nine insect species, the seed-feeding weevil (Smicronyx lutulentus Dietz), the stem-boring weevil (Listronotus setosipennis Hustache), the root- 72 boring moth (Carmenta nr. ithacae Beutenmuller), the leaf-feeding beetle (Zygogramma bicolorata Pallister), the sap-feeding plant-hopper (Stobaera concinna (Stål)), the leaf- Page

mining moth (Bucculatrix parthenica Bradley), the stem-galling moth (Epiblema strenuana Walker), the stem-boring moth (Platphalonidia mystica Razowski & Becker) and the stem- boring weevil (Conotrachelus albocinereus Fiedler) and two rust pathogens, the winter rust (Puccinia abrupta Diet. & Holw. var. partheniicola Jackson Parmelee), and the summer rust (Puccinia xanthii var. parthenii-hysterophorae Seier, Evans & Romero). All but one of these agents have established in central Qld with most of them capable of causing substantial damage to and control of parthenium, although effectiveness of the agents can vary seasonally (Dhileepan and McFadyen 2012). Parthenium has spread into southern Qld and northern New South Wales. These southern Qld infestations are isolated from the core infested areas of central Qld and have presumably resulted from the movement of contaminated stock feed, cattle and machinery. As such, many of the effective and highly damaging agents that are widespread in central Qld have not yet extended their distribution at the same rate as the weed. Therefore, with the support of Meat and Livestock Australia and the Australian Government, a project was initiated to expedite the spread and establishment of agents with limited, if any, distribution in southern Qld (the seed-feeding weevil, the stem-boring weevil, and the root-boring moth, the winter rust, and the summer rust).

MATERIALS AND METHODS

Collection of agents from central Queensland

Parthenium-infested sites in central Qld were visually inspected for parthenium and associated biological control agents from October to April, in 2015/16 and 2016/17 (Figure 1). Field collections were made in November and December 2015, February/March and March/April 2016, October 2016, January 2017, February/March 2017 and April 2017. When present in high numbers, the seed-feeding weevil, and occupied flower stems, were removed and placed into ventilated cylindrical containers lined with moistened paper towel (Callander & Dhileepan 2016). Summer rust was collected as rust-infected leaves, packed flat between sheets of paper towel, or as whole plants collected into paper bags (depending on the severity of the infection). Stems and roots infested with larvae (with flowers, leaves and soil removed) of the Carmenta moth and Listronotus weevil were collected in bulk (Callander & Dhileepan 2016).

Glasshouse culturing

A culture of the summer rust was established at the Ecosciences Precinct (ESP) glasshouse facilities in winter of 2016. Rust-infected leaf material, collected from the Burdekin River in northern Qld, was used to initiate the culture. Large rosettes up to newly bolted parthenium plants were placed into a Perspex inoculation chamber (150 cm (L) x 50 cm (W) x 100 cm (H). Rust-infected leaves were suspended, on a wire grid, above the healthy parthenium rosettes. The inside of the inoculation chamber was sprayed with a light mist of water and then sealed for 48 hours. Plants were removed from the chamber and grown at 22-27ºC for about ten days, until rust pustules were observed.

Field releases in southern Queensland

In consultation and collaboration with community groups and regional councils, 10 release sites were initially identified (Callander & Dhileepan 2016). An additional 12 sites have 73 been surveyed and identified as potential release sites. Field-collected and glasshouse- reared agents were released over two summers and one winter at 19 sites across 10 Page

geographically separate locations (Figure 1). Surveys were conducted periodically, throughout the year, at most of the release sites in southern Queensland.

Mackay

Rockhampton Emerald

Bundaberg

Mitchell

Brisbane

Figure 1. Map of central Qld parthenium biological control collection sites (orange squares) and south and southeast Qld release sites (blue triangles). Black stars indicate nearest major cities or towns. Yellow circles indicate the arbitrarily defined geographically separate areas.

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RESULTS

Winter rust, collected from a previously established site at Helidon Spa, was released at 12 sites in southern Qld from August 2015 to August 2016. The winter rust was recovered from 10 of those sites during winter 2016. However, surveys conducted in winter 2017 failed to recover the winter rust at any of the sites, even at the well-established Helidon Spa site, where material was sourced for redistributions.

Smicronyx weevils, collected from central Qld, was released at nine sites in southern Qld. The agent established quickly at the Biggenden release site spreading to other parthenium infestations in the area as well as west to Munduberra and south to Cherbourg sites, within one year of being released. Adults were subsequently collected from the Biggenden site and released at four additional locations in the North Burnett area, as well as being supplied to other regional councils for release. The Smicronyx weevil is also considered to have established at Ceder Vale/Kamarooka in southern Qld, Junction View, Kilcoy and Helidon Spa in southeast Qld.

Carmenta moths and Listronotus weevils were released at six sites (Kolan River, Tawah Creek, Debilgo Creek, Kilcoy, Junction View and Ceder Vale/Kamarooka) as larval- infested plant material. Surveys conducted in July 2017 revealed larval damage, indicative of Carmenta, at Tawah Creek (Biggenden) and also at Monto (70km from Tawah Creek and 40km from Kolan River release sites). Carmenta moths were recovered from plants collected at Monto, confirming its presence there. Listronotus larvae were recovered from parthenium in Ceder Vale/Kamarooka, in southern Qld, in January 2017.

Summer rust was mass-reared and released at 12 sites in southern Qld from September 2016 to March 2017. A single summer rust release (12 rusty-leaves and two potted plants) was made at Munduberra in September 2016. The summer rust was subsequently recovered at Munduberra in January 2017 and again in March 2017. By contrast, multiple releases were made at Tawah Creek, Debilgo Creek, Kilcoy, Junction View, Helidon Spa, Womalilla Reserve and Ceder Vale/Kamarooka sites across this period, yet the agent was not recovered from these sites at subsequent visits across the summer. Surveys conducted in winter 2017, however, identified the presence of the summer rust at Junction View, Tawah Creek and Debilgo Creek.

DISCUSSION

In contrast to conventional biological control programs, where establishment of an agent can take many years, this project has recorded widespread establishment of many released agents after only two years. This could be attributed to these agents having already acclimatized and adapted to Australian conditions. A good example of this has been the rapid establishment of the Smicronyx weevil at the initial release site north of Biggenden and subsequent spread to sites in the North Burnett and South Burnett regions (connected by river and creek systems). Smicronyx weevils are now widespread in the Biggenden area and have been collected on several occasions by regional council staff to be supplied to other councils.

Despite this success, field collection alone will not be adequate to meet the challenge of redistributing other effective agents (e.g. Listronotus weevils and Carmenta moths) from 75 central Qld to southern Qld. This is due to the variability in the availability of parthenium and its biological control agents in central Qld for collection and also the availability and Page

suitability of parthenium in southern Qld for releases. Ideally, the best time to release agents in southern Qld is early in the parthenium growing season (November to February) when agents have the best conditions to complete a few generations before winter. However, the optimal time to collect insect agents is later in the growing season (January to April) when agents have had time to build in numbers. This highlights the need to supplement the field collections with mass-rearing of an agent to be released throughout the season when parthenium becomes available.

Summer rust, for example, was not recovered in central Qld in the 2015/16 season, thus a glasshouse culture was established from field-collected material from northern Qld. The rust was mass-reared and released in southern Qld throughout the 2016/2017 summer. However, southern Qld experienced a very hot dry summer and, despite repeated release efforts of the rust, it was not recovered at any of the sites. Surprisingly, surveys conducted mid-July revealed a high number of plants infected with summer rust at several of the sites, indicating the releases had been successful.

Collections will recommence in November, as will the mass-rearing and releasing of the summer rust. Future efforts will focus on establishing a glasshouse colony of the Carmenta moth for release during the 2017/18 season. Given the time constraints, limited resources and spatiotemporal variability in climatic conditions affecting both the collection and release of parthenium biological control agents, community and local government involvement has been paramount to the success of the project. To enhance the outcome of this project and ensure that these highly effective agents maintain a foothold in southern Qld, continued redistribution efforts are needed.

ACKNOWLEDGMENTS

The study was funded by the Rural Research and Development for Profit Program (Department of Agriculture and Water Resources), Meat & Livestock Australia and the Queensland Government (Department of Agriculture and Fisheries). We thank Trevor Armstrong (Oxley Catchment Group), Pat Ryan (Junction View Pest Management Group), Ross Bigwood (SEQ Catchments), Bruce Lord (Healthy Waterways & Catchments), Tom Garrett (Queensland Murray-Darling Committee), Glenn Proctor & Neale Jensen (North Burnett Regional Council), Eric Dyke (Bundaberg Regional Council) for contributing their time in identifying potential release sites and efforts to aid in the redistribution of parthenium agents in their area. We also thank Rachel McFadyen, Stephen Downey, Di Taylor and Kumaran Nagalingam for technical assistance with the project.

REFERENCES

Callander, J.T. and Dhileepan, K. (2016). Biological control of parthenium weed: field collection and redistribution of established biological control agents. Proceedings of the 20th Australasian Weeds Conference, 242-245.

Chippendale, J.F. and Panetta, F.D. (1994). The cost of parthenium weed to the Qld cattle industry. Plant Protection Quarterly 9, 73-76. Dhileepan, K. and McFadyen, R.C. (2012) Parthenium hysterophorus L. – Parthenium. In: Biological Control of Weeds in Australia: 1960-2010, eds. M. Julien, R.E. McFadyen and 76 J. Cullen, pp. 648. (CSIRO Publishing, Melbourne). Page

BIOLOGICAL CONTROL: NOT AS SIMPLE AS IT SEEMS

Elizabeth Snow, Michael Day Department of Agriculture and Fisheries, Biosecurity Queensland, Invasive Plant and Animal Sciences, EcoSciences Precinct, Dutton Park, Queensland 4102

ABSTRACT

Few people are aware of the complexities and costs involved with biocontrol research. While the results are generally well-known and, at times spectacularly successful, the process of exploration, importation and secure testing of insects and pathogens is lengthy and expensive. While the total cost of biocontrol in Queensland is difficult to estimate, it is likely to exceed $1M per annum on average. Queensland is very fortunate in having one of the world’s best biocontrol quarantine facilities at the EcoSciences Precinct, Brisbane. This paper takes a “behind the scenes sneak-peek” at this purpose-built facility, and documents the various challenges involved with biocontrol more generally. Containing potential agents in dedicated quarantine facilities is not a straight-forward activity, requiring user-training, strict protocols, regular audits and an intensive facility maintenance program. Once potential agents are imported, the testing required to ascertain host-specificity largely depends on the specific attributes of the insect or pathogen. However, the key factors involve studying the agents’ lifecycle, testing the non-target species most at risk of attack, replication of trials and investigation of any anomalies or off-target activity. Once all these factors are satisfied, an application seeking approval to release the insect can be submitted to the Australian Government (presently Department of Agriculture and Water Resources and Department of Environment). Only after all these steps, can the department proceed to mass-rearing and field-release of a biological control agent.

Keywords: Quarantine facility, QC3, biological control, host specificity testing

INTRODUCTION

Queensland is very fortunate in having one of the world’s best biological control quarantine facilities at the EcoSciences Precinct, Brisbane. The facility meets Class 7.3 quarantine standard for insect containment and a 5.3 containment standard for quarantine. Other quarantine insectary facilities of this rating are located in Canberra and Geelong (both CSIRO) and Orange in central-western New South Wales (New South Wales Department of Primary Industries). Biological control research is a long-term investment, with projects often running for over 10 years. While the total cost of biocontrol in Queensland is difficult to estimate, it is likely to exceed $1M per annum on average. Despite the cost, biocontrol research is an outstanding investment, delivering a benefit to cost ratio of 23:1 (AEC Group 2005). Notable successes have been cactus species with benefit to cost ratio of 77 312:1, rubber vine 109:1 and parthenium 80:1 (Page & Lacey 2006). Investment in Page

biological control is often co-funded, with investment from government, local government and organisations such as MLA and RIRDC.

While many people have heard of biological control and the enormously successful biocontrol of prickly pear back in the 1930s, few are aware of the complexities and costs involved with projects and maintaining a world-class quarantine facility. This paper provides a brief summary of what it takes to run a large biocontrol facility, as well as an overview of the exploration and importation process and the various challenges involved with testing and seeking approval for potential biological control agents.

Target weeds and their agents

The process of biological control starts with a nationally endorsed decision to target a particular weed species for biocontrol research. Exploration then commences in the weed’s country of origin, searching for insects and pathogens considered likely to be both damaging and host-specific. Field locations can be challenging within particular countries in Africa, Asia and South America, presenting unique challenges associated with safety, logistics, permit requirements, climate, disease and language or cultural barriers. Often little is known about the potential agents and some have may not have been described. In such cases, extensive testing is required to ensure host-specificity. Alternatively, there may be weeds that are problems in other countries and have safe and effective biocontrol agents readily available. Countries such as South Africa may have already invested in research for a biological control agent, thus removing the need for native range surveys and other research, saving time and money. Researchers in Australia can refer to these results and then perform additional testing on non-target plants of importance in Australia but not previously tested.

Importation requirements

Once potential agents have been located, an import permit is required to bring exotic insects and pathogens into Australia and each researcher organises a permit for the potential agent they wish to bring into the quarantine. Permits are granted by the federal Department of Agriculture and Water Resources (DAWR) and Department of Environment (DoE). Permits require imported organisms to be moved directly into the QC3 quarantine facility upon entry to Australia. The permit will also stipulate other conditions that must be met, for example; destruction of packing materials and imported plant material, reporting of any associated parasites and any further inspections that need to be conducted subsequent to importation. The main objective is that a paper-trail (or imported goods pathway) is generated from importation through to the eventual release (or destruction) of the insect.

Insects are unpacked in a small unpacking room using a purpose-built Perspex box, with mesh sleeves as a precaution against escape during opening. All the insects are removed individually and placed in clean containers. This also allows capture of any parasites or predators that may accompany the shipment from the country of origin. Individuals of the

biocontrol agent are then transferred to cages in the quarantine glasshouse. All packing 78

material is treated in the autoclave immediately after unpacking and is then discarded. Confirmation of the unpacking procedure and number of insects imported, as well as the presence of parasites must be reported to DAWR within 14 days of importing the insects. Page

Quarantine facilities

The quarantine facility is located on the roof-top of the Ecosciences Precinct in Brisbane. There are six glasshouses within the facility, one of which is the ‘micro’ area specifically designed for microscopic insects (e.g. mites) and plant pathogens (such as fungi). Each glasshouse is constructed with dual layers of glass separated by a 300mm gap. The temperature and humidity of all glasshouses is customised to the specific requirements of each organism and is controlled centrally by a building management system (BMS). Within the quarantine facility there are also three controlled-temperature rooms, an unpacking room, a storeroom and a room housing several smaller temperature control cabinets for individual experiments. Entry to the facility is by swipe card with access limited to those who are quarantine approved persons, i.e. people who have completed DAWR training.

Figure 1 Inside the quarantine glasshouse 100 micron mesh filters provide containment on air handling systems(left) and Inside the quarantine a central hallway leads to the labs and glasshouses (right)

There are several levels of containment within the quarantine, apart from the outside structure. Firstly, insects are housed in mesh cages in the glasshouse. Each glasshouse is pressure-controlled and is maintained at a negative pressure of -75pa. This is separated from the adjoining laboratory space that has a negative pressure of -65pa. This is further separated from the main hallway that has a pressure of -50pa. This pressure gradient directs airflow back towards the glasshouse, hence providing an extra barrier to escape. All air supply and exhaust ducts within the quarantine area have 100 micron mesh filters installed. The air is also HEPA (high efficiency particulate air) filtered prior to leaving the quarantine area. All liquid leaving the facility is sterilised using a liquid waste heat treatment decontamination system (Actini® system located in basement of building) and all solid waste is autoclaved through a double-sided autoclave system. The building has a backup generator to ensure that all these systems remain functional during any power outages and there is no loss of containment.

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All air supply and exhaust system within the quarantine are able to be shut off with

‘dampers’ to allow individual areas to be decontaminated by fumigation with chlorine Page

dioxide gas at the end of every project or as required during a major shut down for maintenance works that may be required in future. Regular maintenance works present unique challenges as trade equipment that goes into the quarantine may not be able to be decontaminated and must be left inside the quarantine. For this reason, a supply of tools like power drills and ladders are permanently kept inside the quarantine. Items such as drill bits or metal tools can be easily decontaminated using 80% alcohol for removal (using a process approved by DAWR). Removal of items such as computers can be done by a process that is agreed with DAWR prior to removal of items and usually involves freezing the item for a period of time and then treating with 80% alcohol. The micro area of quarantine has a more rigorous treatment regime and some items cannot be removed without destruction by heat.

Staff are required to wear plastic suits, boots and hairnets that they remove in a change room upon exiting the facility and staff are required to either wear gloves while using the facility or use hand sanitiser on exit. Additionally, the micro area of quarantine requires staff to shower for three minutes on their way out of the facility. There are also interlocking doors when leaving the quarantine facility. For safety, staff are also required to wear a ‘man-down’ alarm as they are often working alone.

Figure 2. A complex array of air handers, including HEPA air filters and humidifiers for the quarantine facility is housed on the level below the facility.(right) and fumigation chambers and autoclaves are integral to sterilisation and decontamination protocols

The physical structure and systems of the facility require regular maintenance to ensure that facility remains secure. Maintenance includes servicing of air handlers (HEPA filter fumigations, six monthly mechanical part replacement, cleaning of mesh), pressure testing for structural leaks, waste management systems and autoclave calibration. All maintenance work conducted in the quarantine area requires an SOP (standard operating procedure - DAWR approved) to ensure work procedure meets standards to ensure containment. It is a mandatory requirement that records are maintained for all this work and paperwork needs to be available for DAWR audits. All protocols must be met to satisfy quarantine conditions and audits that are conducted regularly by DAWR who examine paperwork and physical protocols. DAWR will issue a ‘corrective action required’ directive if protocols are not met so any problems identified need to be dealt with promptly 80

(usually within 21 days of issue depending on the nature of problem).

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Testing of biocontrol agents

Once agents are imported, they need to be tested to ensure that they are host-specific, i.e. an insect can only breed and sustain a viable population, or pustules of the pathogen can only develop, on the target weed. To do this, a host-test list is researched for each agent and the ‘centrifugal’ test method is used. This involves identifying plants within the weed species’ own taxonomic group, i.e. genus and closely related families, with a particular emphasis on native plants and those of economic importance. The type of testing procedure varies depending on the agent. The most robust method is ‘no-choice’ testing where adults, eggs or larvae are placed on individual non-target plant species without the presence of the target weed to determine any impacts (feeding, oviposition, development) on the test species. Up to 80 species of plants may be required for testing. Presently in quarantine we have agents being tested on bellyache bush (40 species for testing), Cylindropuntia cacti, mikania (only 20 Australian species tested due to overseas research done previously) and prickly acacia (70 species for testing).

Release approval

Once all testing is complete, an application is made to the DAWR who passes their recommendation to the DoE for ministerial sign off for release in Australia. If permission is granted, the biological control agents are moved from the quarantine facility to glasshouses for mass-rearing and distribution onto the target weed.

CONCLUSION

Exploration for potential biological control agents, their subsequent importation and testing can take several years. Utilising the results of research in other countries can sometimes save significant money and time Primary containment of agents is not the only consideration, with the quarantine facility itself having complex running requirements and proof of the maintenance of these various systems is required to satisfy regular DAWR audits.

REFERENCES

AEC Group (2005). Economic impact assessment of Australian weed biological control effort, final report prepared for the CRC for Australian Weed Management, AEC Group, Brisbane.

Page, A.R. and Lacey, K.L. (AEC Group) (2006), Economic impact assessment of Australian weed biological control, CRC for Australian Weed Management Technical Series, #10

Palmer, W.A., Heard, T.A., Duffield, B. and Senaratne, K.A.D.W. (2011) Australia’s

Newest Quarantine for Weed Biological Control, XIII International Symposium on 81

Biological Control of Weeds. Waikola, Hawaii, USA, 11-16 September 2011, pp. 14-19 ref.9 Page

TO BURN OR NOT TO BURN: USING FIRE TO MANAGE A COMPLEX GRASS ECOSYSTEM

Wayne Vogler Biosecurity Queensland, Department of Agriculture and Fisheries, Tropical Weeds Research Centre, P.O Box 187 Charters Towers, Queensland 4820, Australia.

ABSTRACT

Grader grass (Themeda quadrivalvis) and Indian blue grass (Bothriochloa pertusa) are among a number of invasive grasses causing significant problems for land managers in northern Australia. These grasses are capable of forming monocultures that reduce grazing animal production and change ecosystem processes such as altering fire behaviour and reducing habitat for native fauna. In northern Australia, fire is a relatively common part of the ecosystem either by deliberate burning or through uncontrolled wild fire. A study of grader grass and Indian blue grass responses to fire in a conservation setting was undertaken at Undara Volcanic National Park from 2006 to 2013 in an area where the two species were growing together.

Grader grass and Indian blue grass responded differently to fire. Annual fires maintained high levels of grader grass biomass while Indian blue grass biomass slowly declined to near zero. An opposite response occurred where fire was excluded with grader grass biomass slowly declining while Indian blue grass biomass increased significantly. Where periodic burning was undertaken, Indian blue grass increased in the years between fires but rapidly declined in the year following a fire. In contrast, grader grass biomass declined in non-fire years and rapidly increased in the year following a fire. The land management implications of the differential fire responses of grader grass and Indian blue grass are discussed.

Keywords: Grader grass, Indian blue grass, fire, Queensland, invasive grasses.

INTRODUCTION

Invasive exotic grasses are a significant threat to biodiversity, productivity and infrastructure in the northern Australian rangelands (Grice 2006; Rossiter et al. 2003; Rossiter et al. 2009; Vogler and Owen 2008). These grasses include high biomass tussock and low growing stoloniferous types, annual and perennial species, and palatable and non-palatable species for livestock production. Each species contributes either positive or negative changes to conservation and production values of the dry tropical savannah regions of northern Australia (Lonsdale 1994; Grice et al. 2012).

Many high biomass invasive grasses are well adapted to fire and generally increase under a frequent fire regime (Setterfield et al. 2013). These grasses also increase fire intensity increasing potential damage to infrastructure, flora and fauna, and making fires more difficult to manage (Rossiter et al. 2003; Rossiter et al. 2009). This is of particular concern 82 in northern Australian where seasonal fire is common either as wildfire or as a controlled fire for hazard reduction or other land management purposes (Setterfield et al. 2013).

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In conservation areas in the northern Australian rangelands, land management is aimed at maintaining the flora and fauna diversity and natural amenity for the wider community. This is largely done by applying fire regimes that support the health of the ecosystems within these areas (The State of Queensland Department of National Parks, Recreation, Sport and Racing 2013). Where invasive grasses such as grader grass (Themeda quadrivalvis) and/or Indian blue grass (Bothriochloa pertusa) are dominant, using fire as the sole land management option can become problematic because both these species impact fire behaviour. Grader grass is known to increase fire intensity (Vogler and Owen 2008) whilst Indian blue grass appears to cure slowly and can reduce the effectiveness of planned hazard reduction burning (Rossiter-Rachor 2017). To understand the fire response of these grass species, a fire frequency and seasonality trial commenced in 2006 at Undara Volcanic National Park and ended in 2013 when most of the trial site was accidently burnt. This paper describes some of the outcomes of this trial and discusses the implications for conservation management where these species are present.

MATERIALS AND METHODS

A randomised complete block experiment to determine the response of grader and Indian blue grass to fire treatments was established at Undara Volcanic National Park (18o13’00.03”S;144o39’27.98” E) during September 2006, in an area dominated by grader grass with an associated minor level of Indian blue grass. Eleven treatments (Figure 1) including a herbicide treatment and a control, replicated three times were applied to thirty- three 10 x 40 m plots. Plots were separated by 10 m slashed breaks which were maintained for the duration of the trial. This enabled each plot fire to be contained to that plot and allowed easy access for fire control vehicles.

The fire treatments were applied annually, biennially or quadrennially each during the late dry season, early wet season after grader grass seedling emergence and the late wet season as soon as the grass had cured enough to carry a fire. The herbicide treatment was an annual paraquat (500 g/ha a.i.) application when grader grass seed heads had emerged. It was applied using a boom spray delivering a spray volume of 200 L ha-1 at a pressure of 2 bar using Teejet® AIXR air induction tapered fan nozzles (Nozzle code AIXR110025-VP).

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Figure 1. Plot layout at Undara Volcanic National Park in February 2012.

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Fires were conducted as head fires in each plot to mimic the natural movement of fires directed by the wind (Figure 2). Prior to each fire, fuel moisture and biomass were determined by cutting, drying and weighing the fuel in two randomly selected 50 x 50 cm quadrats in each plot. Ambient temperature and humidity as well as wind speed were measured immediately prior to each plot fire. Changes in the botanical composition of the grass layer were assessed in forty 50 x 50 cm quadrats in each plot using the BOTANAL method (Tothill et al. 1992). These assessments were done prior to the commencement of the trial and then annually at the completion of the growing season in April or May prior to the application of the late wet season fire treatments. Data was analysed using GENSTAT 16 (VSN International) and presented graphically.

Figure 2. A head fire in a plot at Undara Volcanic National Park in October 2010.

RESULTS

Biomass in each plot ranged from about 1000 kg/ha to more than 9000 kg/ha following poor (2009/2010) and above average wet seasons (2010/2011) respectively. The fire responses of grader and Indian blue grass were markedly different with the biomass of grader grass increasing to more than 80% of total biomass whilst the biomass of Indian blue grass decreased to near zero in frequently burnt treatments (Figure 3). Regardless of fire frequency, timing or rainfall conditions there was a consistent trend for grader grass biomass to increase and that of Indian blue grass to decrease following fire treatment application.

In both control and herbicide treatments where there was minimal vegetation disturbance over the life of the project, grader grass biomass declined steadily to almost nil. This is in contrast to Indian blue grass biomass which increased to more than 40 and 60% of the total biomass in the control and herbicide treatments respectively (Figure 3). The biomass of other significant species including black spear grass (Heteropogon contortus), wire grass (Aristida spp.) and sabi grass (Urochloa mosambicensis) fluctuated with seasonal conditions and treatment and reached more than 50% and 30% in control and herbicide treatments respectively at the conclusion of the trial.

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DISCUSSION

The results of this study indicate that both of these grasses pose a threat to the conservation values of national parks, particularly where the vegetation communities are maintained primarily by periodic burning. Clearly increases in grader grass populations are driven by frequent fire similar to that observed with gamba grass (Setterfield et al. 2013) whilst it appears that Indian blue grass favours limited disturbance and exclusion of fire (Figure 3).

Where each species occurs on its own within grass communities in conservation areas, their suppression is likely to be improved through judicious use of fire. For example burning Indian blue grass infested pasture systems may be an option to reduce its proportion and encourage native species such as black spear grass (Orr et al. 1997) thereby improving production and conservation values. However where they occur together in plant communities, periodic fire or fire exclusion is likely to favour one species over the other, resulting in a deleterious effect on that community by at least one of these species. In cases such as this, the conservation values of the plant community may be irreparably damaged whether or not fire is included or excluded. Strategic use of herbicides for small infestations may be an option for grader grass control where Indian blue grass is not present (Figure 3) however selective herbicide options are limited. This may necessitate choosing the management regime that causes the least ecosystem damage, particularly in extensive landscapes, although this may be difficult as both Indian blue and grader grass can form near monocultures in a relatively short period. It may require a level of acceptance that a permanent change to conservation ecosystems is likely where invasive grasses are present.

ACKNOWLEDGEMENTS

This study was co-funded by North Queensland Dry Tropics Natural Resource Management, Northern Gulf Resource Management Group, Southern Gulf Natural Resource Management and the Department of Agriculture and Fisheries. In kind support has been given by Queensland Parks and Wildlife Service, Department of Natural Resources and Mines Fire Management Unit North Region. In particular the support given by John Clarkson, Nick Smith and colleagues from Undara Volcanic National Park is gratefully acknowledged, as is the assistance from Tropical Weed Research Centre staff Nikky Owen, Ashley Owen, Dannielle Brazier, Will Green, Laura Roden, Rodney Stevenson and Carl Andersen. Thanks also to Shane Campbell and Joe Scanlan for comments on earlier drafts of this paper.

REFERENCES

Grice, A.C. (2006). The impacts of invasive plant species on the biodiversity of Australian rangelands. The Rangeland Journal 28: 27–35.

Grice, A.C., Friedel, M.H., Marshall, N.A. and Van Klinken, R.D. (2012). Tackling contentious invasive plant species: A case study of buffel grass in Australia. Environmental Management 49: 285–294.

85 Lonsdale, W.M. (1994). Inviting trouble: introduced pasture species in northern Australia. Australian Journal of Ecology 19:345–354.

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Orr, D.M., Paton, C.J. and Lisle, A.T. (1997). Using fire to manage species composition in Heteropogon contortus (black spear grass) pastures. 1. Burning regimes. Australian Journal of Agricultural Research 48: 795-802.

Rossiter, N.A., Setterfield, S.A., Douglas, M.M. and Hutley, L.B. (2003). Testing the grass- fire cycle: alien grass invasion in the tropical savannas of northern Australia. Diversity and Distributions 9: 169–176.

Rossiter-Rachor, N.A., Setterfield, S.A., Douglas, M.M., Hutley, L.B., Cook, G.D. and Schmidt, S. (2009). Invasive Andropogon gayanus (gamba grass) is an ecosystem transformer of nitrogen relations in Australian savanna. Ecological Applications 19(6): 1546–1560.

Rossiter-Rachor, N.A. (2017). Pers. comm. Charles Darwin University.

Setterfield, S.A., Rossiter-Rachor, N.A., Douglas, M.M., Wainger, L. and Petty, A.M. (2013). Adding fuel to the fire: The impacts of non-native grass invasion on fire management at a regional Scale. PLoS ONE 8(5): e59144.

The State of Queensland Department of National Parks, Recreation, Sport and Racing. (2013). Planned Burn Guidelines – Cape York Peninsula Bioregion of Queensland.

Tothill, J.C., Hargreaves, J.N.G., Jones, R.M. and McDonald, C.K. (1992), BOTANAL – A comprehensive sampling and computing procedure for estimating pasture yield and composition. 1. Field sampling. Tropical Agronomy Technical Memorandum Number 78. (CSIRO Division of Tropical Crops and Pastures).

Vogler, W.D. and Owen, N.A. (2008). Grader grass (Themeda quadrivalvis): changing savannah ecosystems. In: van Klinken, R.D., Osten, V.A, Panetta, F.D. and Scanlan J.C. (eds). Proceedings of the 16th Australian Weeds Conference. Queensland Weeds Society, Brisbane. p 213.

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Figure 3. Mean biomass proportion of grader and Indian blue grass subjected to burning, and herbicide treatments at Undara Volcanic National Park. Treatment differences for each species are indicated by errors bars (+ or – one SEM). Arrows indicate the timing of fires.

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MANAGING BUFFEL GRASS TO PROMOTE SPECIES RICHNESS AND FACILITATE ECOSYSTEM RECOVERY

Melzer R.1 and Melzer A.2 1 Ecological Assessment Unit, Queensland Parks and Wildlife Service, Department of National Parks, Recreation, Sport and Racing, Rockhampton, Qld 4701. 2School of Medical and Applied Science, CQ University, Rockhampton, Qld 4702.

ABSTRACT

Buffel grass (Cenchrus ciliaris) is an important introduced pasture grass but it is also a serious environmental weed driving ecosystem change through altered fire regimes and competitive exclusion. Evaluation of herbicide trials, and of stock grazing, is underway on protected area estate to determine treatment effectiveness in facilitating recovery of fire- sensitive ecosystems and promoting native species richness. The results of small scale trials, which indicated that herbicide treatment of buffel grass swards can release latent richness in herbaceous communities (Melzer et al. 2015), are discussed together with the progress of broad scale herbicide trials, as well as outcomes from ten years of pulse grazing buffel grass in fire-sensitive Brigalow regrowth.

INTRODUCTION

The management of buffel grass impacts on conservation values requires an integrated approach. This often includes techniques such as manual, mechanical and herbicide control. However, none of these techniques are appropriate options over the large areas of reserves where buffel grass is already well established and abundant. Fire, which can be used as a broad-scale management tool for a range of purposes, is widely recognised as exacerbating the impacts of buffel grass. Nevertheless, it may be appropriate in fire- adapted vegetation as part of an integrated control program, and otherwise will be required from time to time to maintain species and ecosystems. Biological control, through stock grazing, is currently the only feasible ‘tool’ for managing buffel grass to achieve conservation outcomes where the infestation is extensive and the native vegetation is fire- sensitive. Stock grazing should only be considered for use as a management ‘tool’ on conservation reserves, such as national parks, when there is no other effective means to protect or restore a significant natural value (Melzer 2015).

The Queensland Parks and Wildlife Service (QPWS) uses a decision tree to help determine appropriate options for managing buffel grass on protected area estate (Figure 1.) and, together with CQ University, is monitoring their effectiveness and running trials exploring additional options. In this summary we provide results from some of those monitoring programs and trials – grazing to protect or recover fire-sensitive ecosystems invaded by buffel, and spraying trials to recover native species richness in buffel grass dominated landscapes.

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Figure 1. Decision tree to help determine appropriate management options for reducing the impacts of buffel grass on natural values in conservation reserves (from Melzer 2015).

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SUMMARY

Grazing

Grazing is currently being used on four protected areas to protect or recover fire-sensitive ecosystems at risk or already significantly impacted by buffel grass fuelled fires (Scenario 2a in Figure 1.). The two longest running grazing programs are on Albinia Conservation Park and parts of Taunton National Park (Scientific) – commenced 2005 and 2012-2014, respectively. The primary purpose of the grazing has been to reduce the risk of fire entering fire-sensitive regrowth including, in the case of Taunton NP (Sci), habitat of the endangered bridled nailtail wallaby. This has been entirely successful. The ultimate goal for patches of regrowth – that of recovering a functional ecosystem with structure and composition similar to equivalent remnant – is long-term, but will not be achieved without fire exclusion. Albinia Conservation Park Albinia CP was cleared in the 1980s, of what would now be recognised as an endangered ecosystem (a brigalow/bonewood ‘scrub’), and sown to introduced pasture grasses including buffel. The intention is to continue pulse grazing, leading up to the fire season, until the canopy cover is sufficiently dense to suppress buffel, and other pasture grasses, to the point where the risk of fire carrying is very low. Since grazing commenced the canopy cover has increased from 3-18% (Figures 2 and 3.) and is showing early signs of grass suppression (Figure 4.). Parameters such as understorey cover, species diversity and bird assemblages are also being used to evaluate the progress of recovery and will be reported elsewhere in the next few months.

Canopy cover 1 km transect 200 1 km transect 2005 2007 2009Year2011 2013 cover % O/S O/S %

Figure 2. Percentage canopy cover along a 1 km transect in Albinia CP.

Figure 3. Photo point along a 1 km transect in Albinia CP. The left and right images were 90 taken in 2005 and 2016, respectively. The quadrat in the left image is 1 m square; a 2 m surveyor’s pole is situated in the centre of the right image behind the brigalow shrub. Page

Figure 4. Halo effect of grass suppression under brigalow clumps in Albinia CP, 2016.

Taunton National Park (Scientific) Taunton NP (Sci), and surrounds, is home to the sole wild population of the endangered bridled nailtail wallaby – a species that formally extended from Central Queensland to Victoria. Brigalow forms a critical component of its habitat, so the substantial invasion of buffel grass is a serious threat to the species. Here too, the canopy cover of regrowth is recovering with fire exclusion afforded by grazing (Figure 5.). A further goal at Taunton NP (Sci) however, is to shift the competitive advantage in the ground stratum from buffel grass to native species and in particular bridled nailtail wallaby fodder species. Buffel grass rundown has been observed in the Clermont district in pastures heavily grazed for 20+ years, particularly where heavy grazing occurs at the end of the growing season (J. Chamberlain pers. comm.). Buffel grass seems to derive its dominance from an expansive root system providing advantages in nutrient and water absorption (Marshall et al. 2012) and it is reported to have an allelopathic effect on some species (Fulbright and Fulbright 1990). Substantial weakening of the root system is likely to be needed before significant shifts in competitive advantage occur and, unsurprisingly given the timeframe, this has not yet occurred on Taunton NP (Sci).

Figure 5. Recovery at Site P1N, Taunton NP (Sci), which burnt in July 2010; grazing commenced in February 2014. The left and right images were taken in 2012 and 2017, respectively.

Spray trials 91

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In a pilot study, twenty 25x25 m plots were established in 2009 in buffel grass dominated grassland on Taunton NP (Sci). The aim was to test the effect of herbicide treatment on ground stratum species richness. The site was formally a brigalow community but had been transformed by recent historical land management practices, and wildfire, and had been buffel grassland for at least 27 years. Ten of the plots were sprayed once with Roundup Biactive® (glyphosate 450 g/l to 100 parts water) when the plants were actively growing – resulting in 100% kill of herbaceous plants (Melzer et al. 2015).

Results at 12 months indicated that the removal of buffel grass increased herbaceous species richness. More surprising however, was the longevity of response. Over three years (39 months) post spraying the treated plots had significantly less foliage cover and litter, and significantly more bare ground and species, than the control plots and double the number of known bridled nailtail wallaby fodder species (19 versus nine) (Melzer et al. 2015). These results prompted the establishment of larger scale trial plots to examine (a) the nature of the response following the destruction of the buffel ground cover; (b) duration of the suppression of buffel grass: (c) the recovery of buffel grass; and (d) the logistical constraints and economics associated with the application of herbicides within a conservation reserve. Four, 1 ha plots were established – one as a control while the other three were to be sprayed once, twice and three times, respectively (Melzer and Dinwoodie 2012).

These larger scale trials are still underway but the change in species richness in the sprayed plots is substantial compared to their pre-spray situation and the control plot (Table 1 and Figure 6.).

Table 1. Species richness pre- and post-spray treatments, Taunton NP (Sci). Plot no. Treatment Species richness (up to April 2017) 2011 2017 (pre-spray) 1 Sprayed twice 3 32 2 Sprayed twice 7 42 3 Sprayed once 13 22 4 Unsprayed (control) 8 7

CONCLUSION

Stock grazing is currently the only feasible ‘tool’ for achieving conservation outcomes where buffel grass infestations are extensive and ecosystems are fire-sensitive. It enables fire-sensitive remnants to be protected from fire and provides opportunity for regrowth to recover over time. Recovery to a functional ecosystem similar in composition and structure to a remnant will be slow particularly if the regrowth has already been compromised by severe fire – long term perspective is needed! Spraying is known to be effective for small infestations of buffel grass but broad scale control using herbicide will rarely be possible because of resource constraints – especially as follow-up will be needed; perhaps forever. Nevertheless, early results from spray trials at Taunton NP (Sci) suggest there may be opportunities to achieve conservation benefits, such as increased species richness, over reasonably broad areas of fire-adapted vegetation through the use 92 of herbicide.

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Figure 6. Taunton NP (Sci) – Google Earth imagery. The left image is prior to the establishment of the spray plots. The right image is 2017 and shows the north-south oriented fenced rectangular trial area. The latter is divided into four plots – the southern- most plot (green square) is the unsprayed control.

REFERENCES

Fulbright, N. and Fulbright, T.E., (1990). Germination of two legumes in leachate from introduced grasses. Journal of Range Management 43(5): 466-467.

Marshall, V.M., Lewis, M.M., and Ostendorf, B. (2012) Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments 78: 1-12.

Melzer, A. and Dinwoodie, A. (2012). Facilitated regeneration of brigalow ecosystems at Taunton National Park (Scientific) – report 4: vegetative response. Centre for Environmental Management, Central Queensland University and Queensland Parks and Wildlife Service. Unpublished report.

Melzer, A., Melzer, R., Dinwoodie, A., and Beard, D. (2015). Recovery of herbaceous species richness following herbicide treatment of Cenchrus ciliaris (buffel grass) – a pilot study in Onychogalea fraenata (bridled nailtail wallaby) habitat restoration. Proceedings of the Royal Society of Queensland 119: 7-20.

Melzer, R. (2015). When is stock grazing an appropriate ‘tool’ for reducing Cenchrus

ciliaris (buffel grass) on conservation reserves? Proceedings of the Royal Society of

Queensland 120: 53-68. 93

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GIANT RAT’S TAIL GRASS: LESSONS LEARNT FROM CONTROL TRIALS AND LANDHOLDER ENGAGEMENT IN THE MACKAY WHITSUNDAY REGION

Emily Wood Pest and Weed Project Officer, Reef Catchments (Mackay Whitsunday Isaac NRM Group) PO Box 815, Mackay QLD 4740

ABSTRACT

Giant rat’s tail grasses (GRT) are major weeds of concern for the grazing industry in Queensland. The commonly used acronym GRT is used to describe two species of the Sporobolus genus originating from southern and sub-Saharan Africa.

In 2014, funding secured by Reef Catchments NRM Group through the Queensland Department of Natural Resources and Mines NRM Investment Program was allocated to address key questions about GRT control in the Mackay Whitsunday region. These questions shaped the establishment of two control trials in the area. Findings from these trials were communicated to landholders through extension events held across the region in 2016 and 2017. Knowledge gaps preventing effective control were also identified and addressed through these landholder engagement activities.

Keywords: Giant rat’s tail grass, Sporobolus, control trials, landholder engagement

INTRODUCTION

Giant rat’s tail grass (GRT) is a common name for two of the four weedy Sporobolus species categorised as Restricted biosecurity matter under the Queensland Biosecurity Act 2014. The two GRT species, Sporobolus pyramidalis and Sporobolus natalensis, can dominate native and planted pastures, impact species richness, compete for water, nutrients and light and transform fire regimes (Bray and Officer 2007, Department of Agriculture and Fisheries 2016 and Grice et al. 2013). Control of Sporobolus grasses involves consideration of a series of complex interconnected variables including, but not limited to; soil type, soil quality, rainfall, pasture composition, choice of chemical, method of application, timing, stocking rates and stock movements and implementation of biosecurity measures.

This paper outlines outcomes from GRT trials investigating control variables for GRT and

landholder engagement undertaken to identify knowledge gaps and key barriers to control 94 in the Mackay Whitsunday area. Lessons learnt through this project will help to inform the ongoing management of weedy Sporobolus species in the Mackay Whitsunday Region. Page

Sharing of these lessons and continuing the conversation about GRT control challenges and successes at a local, state and national level will be essential for the achievement of meaningful long term control outcomes for GRT and other weedy Sporobolus grasses.

LESSONS FROM THE TRIALS

Reef Catchments trial sites were established in 2014 and were managed in collaboration with landholders, Pioneer Catchment Landcare and the agronomist consultancy Farmacist, who were engaged to assist with delivery of the trials at the end of 2015. Both sites were heavily infested with GRT prior to commencing control activities. Soil tests were taken at both sites. A variety of control methods were used at each site, including various combinations of fire, cultivation, and selective and non-selective herbicides, as outlined below. The most important message to take away from these trials is the evident reduction in GRT at both sites over just two years. Blue Mountain trial - Despite some challenges impacting consistent management at the Blue Mountain site, findings from the trial after 2 years were similar to those from the Gargett site. At Blue Mountain removal (killing) of existing dense GRT by cultivation followed by planting a suitable pasture mix such as Tully Humidicola (bare) @ 2.4 kg / ha; Bare Callide Rhodes (coated) @ 9.6 kg / ha; Bisset Creeping Blue Grass (coated) 4.8 kg / ha; Signal Grass (bare) 2.4 kg / ha; and Cavalcade Centro (bare with inoculum) 2.4 kg / ha) reduced infestation densities by more than 50 %. This along with follow-up spot spraying and careful pasture management should provide the basis for long term GRT management. Gargett (Bradshaw) trial site - Key findings from the Gargett site revealed the importance of removing all existing dense GRT at heavily infested sites prior to planting beneficial competitive pasture species. Plots where all existing plants were removed using a suitable herbicide (eg. Roundup® 360 g/L glyphosate @ 6 L/ha) or an offset disc followed by planting suitable pasture species (eg Signal Grass 5kg/ha, Bare Reclaimer Rhodes 4kg/ha, Cardillo Centro 2kg/ha), along with follow up spot spraying (TASKFORCE®;745 g/L flupropanate @ 200ml / 100 L water) produced large reductions in GRT (from 80% to 20%) while providing significant amounts of forage for livestock. Plots where beneficial competitive pastures were planted without first removing all GRT plants sustained large infestations of GRT throughout the trial period.

LESSONS FROM LANDHOLDER ENGAGEMENT

As part of Reef Catchments landholder engagement activities, a survey was distributed to landholders collecting details about GRT infestations and control efforts across the region. A total of 64 landholders completed the survey between March and June 2017. One of the questions asked respondents ‘what are the main questions you would like to have answered about GRT management?’ Responses to this question were grouped into

themes and are summarised below. 95 • Herbicide application - timing, rate, integrated control, when to follow-up, other effective chemicals, herbicide mixes and testing for soil flupropanate levels. Page

• Best practice management advice – situation specific advice, best control methods, is eradication possible, documentation of successful control by other landholders, long term control strategies. • Assistance with control costs – is assistance available to offset control costs? • Biosecurity planning and spread prevention – landholder obligations, access to wash down facilities, enforcement actions against landholders who do nothing, effective spread prevention strategies. • Bio-control developments – when will biocontrol be available, what is happening in biocontrol? • Challenges of identification – training and assistance with identification and in particular at a young age to assist with control. • Competitive pasture advice – establishment, effect of Taskforce on pasture establishment, encouraging existing pasture to compete with GRT. • Other issues – does soil chemistry/nutrient level affect spread, options for killing plants and seed in the soil, possibilities with gene technology.

These responses were combined with other verbal feedback and communication with key stakeholders to inform the focus of three GRT workshops held across the region at the end of June. Further consultation from these workshops was combined with the survey responses to extract four key GRT action areas to address:

Identification of GRT: landholders and contractors need more support identifying Sporobolus grasses. Consultation with landholders and key stakeholders through this project revealed that many were not confident in identifying GRT with mis-identifications resulting in failure to detect or control GRT. More education on correct herbicide use: landholders requested more information about the herbicides they are using, how to correctly apply them and how they work. Engagement with landholders revealed common chemical use practices not in line with label recommendations indicating a need for further education in this area. There is no quick fix: solving the problem rapidly and cheaply would be ideal, however an attitude of holding out for a ‘silver bullet’ method has led to delayed action on some properties in the Mackay Whitsunday region. Wherever landholders are not acting to control GRT using currently available best practice, infestations continue to increase, spread and consequently become more difficult and expensive to treat. At a local level, stakeholders need to shift the discourse away from waiting for ‘quick fix’ solutions and towards extension efforts to ensure that key stakeholders are actively managing GRT to the best of their abilities now, minimising distribution and abundance of existing infestations as much as possible with available knowledge and resources. We need to get better at working together: a significant number of resources exist and there are stakeholders across Queensland targeting the issue of GRTs. More regular communication and collaboration between these stakeholders will need to occur into the future in order to achieve long-term control outcomes. 96

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Lessons learnt from this project will continue to inform future efforts to meet demand for GRT control advice and extension activities in the Mackay Whitsunday NRM region. Local efforts to address the issue of GRT need to focus on encouraging the community discourse to shift away from the concept of eradication and ‘quick fix’ solutions towards achieving long term outcomes through commitment to consistent, integrated and context appropriate management practices.

ACKNOWLEDGEMENTS

Reef Catchments would like to acknowledge the ongoing efforts of landholders in the Mackay, Whitsunday and Isaac regions towards management of GRT. We would also like to acknowledge staff from Farmacist and Pioneer Catchment Landcare for their efforts at the Gargett and Blue Mountain trial sites and assistance with extension activities. Thanks to Allan Blair and Jim Fletcher from the Queensland Department of Agriculture and Fisheries (DAF) and Shelley Molloy from Mackay Regional Council for their assistance with extension activities; and to Wayne Vogler, Joseph Vitelli, John Reeves and Lalith Gunasekera from DAF for their technical support, guidance and efforts editing this paper.

REFERENCES

Bray, S., Holmes, B., & Officer, D. (2008). Economic analyses of options for weedy Sporobolus grass management. The Rangeland Journal, 30(3): 375-381.

Bray S., and Officer D. (2007). ‘Weedy Sporobolus Grasses Best Practice Manual.’ (Department of Primary Industries and Fisheries, Queensland: Brisbane.)

Department of Agriculture and Fisheries (2016). ‘Rat’s tail grasses fact sheet’. https://www.daf.qld.gov.au/__data/assets/pdf_file/0010/69616/IPA-Giant-Rats-Tail-Grass- PP48.pdf (Queensland Government Brisbane)

Grice, A.C., Vanderduys, E.P., Perry, J.J. and Cook, G.D., (2013). Patterns and processes of invasive grass impacts on wildlife in Australia. Wildlife Society Bulletin, 37(3), pp.478- 485.

Shrestha, S., Graham, G.C., Loch, D.S. and Adkins, S.W., (2012). Molecular marker tools for the identification of weedy Sporobolus species in Australia. Pakistan Journal of Weed Science Research, 18(Special Issue), pp.609-617.

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Walton, C. (2002). ‘Weedy Sporobolus Grasses Strategy – 2001-2006 (2001)’

(Department of Natural Resources and Mines, Queensland: Brisbane.) Page

THE POTENTIAL FOR FERTILISER TO CONTROL WEEDY SPOROBOLOUS SPP. IN CENTRAL QUEENSLAND: RESULTS FROM BYFIELD.

John Reeve1, Stuart Buck2 and Leisa Childs3 1Biosecurity Queensland, Department of Agriculture and Fisheries, Rockhampton. 2Agri- Science Queensland, Department of Agriculture and Fisheries, Rockhampton. 3Livingstone Regional Council, Yeppoon.

ABSTRACT This paper reports the final results of research into weedy Sporobolous spp. grass control using fertiliser in coastal central Queensland. In 2014/2015 a single application of herbicide pellets, GP Flupropanate® (e.g. 86.9 g/kg flurpropanate, produced by Granular Products) was applied (label rate, 13kg/ha) across 4 ha at two sites located at Miriam Vale and Byfield. The Miriam Vale site was heavily infested (60%) with giant rat’s tail grass (GRT) (Sprobolous pyramidalis), whereas at the Byfield Site contained 50% Parramatta grass (S. africanus). Half of each site also received an application of Nitrogen (N) and Phosphorous (P) fertiliser, after the herbicide was applied. A second application of fertiliser was applied a year later, and the Byfield Site received a third application of fertiliser in October 2017. The results of the Miriam Vale site were reported in 2015 (Reeve et al 2015) and this paper will focus on the results from the Byfield site. After the first fertiliser application, the pasture legume round-leaf cassia cv. Wynn (Chamaecrista rotundifolia) grew vigorously creating a mixed sward that also included humidicola (Brachiaria humidicola) and Parramatta grass. During winter, when this legume is most palatable, the mixed sward was readily consumed by cattle. After fertiliser was applied in the second year, 93% of the pasture dry matter was the improved and highly competitive tropical sown grass humidicola, compared to 40% in unfertilised area. At the same time, Parramatta grass accounted for 2.8% of the fertilised pasture, compared to 6.5% in the unfertilised and 50% in the unstocked and unfertilised area. After the initial application of herbicide, there has been very successful, herbicide free, control of the Sporobolous spp using commonly available fertiliser at economical rates that also resulted in increased pasture productivity and quality.

INTRODUCTION. Controlling weedy Sporobolus spp. grasses such as GRT and Parramatta grass using fertiliser is generally regarded as a novel concept. This paper reports the final outcomes of using both herbicide and fertiliser to control weedy Sporobolus spp. grass species, while improving the production (and competitiveness) of desirable tropical pastures at two locations, Miriam Vale and Byfield. The paper presented at the previous weed symposium (Reeve et al 2015) reported results from the Miriam Vale site as treatments were applied nine months earlier than the Byfield site. This paper only reports the results from the 98 Byfield site. Page

The Byfield site has been measured for two pasture growing seasons, and during this time the site was impacted by tropical cyclone Marcia. The uniqueness of this site is high rainfall, high clay content with poor natural soil fertility, minimal expected cattle production and high susceptibility to Sporobolous spp. weed invasion. These factors, especially high rainfall during a short summer season, and high clay component, can affect the success of any herbicide (Reeve et al 2015).

RESULTS

High pasture dry matter yield (8280kg/ha) was measured in the unfertilised/unstocked area due to the lack of grazing animals (Figure 1). Where cattle grazed, pasture dry matter was reduced to 4456kg/ha in the fertilised area, and 2664kg/ha in the unfertilised area (Figure 1). Fertilising provides substantial pasture yield improvement at this location, even when grazing stock are present.

Figure 1. Total dry matter (kg/ha) yield for fertilized grazed, unfertilized grazed and unfertilized and ungrazed at Byfield in 2017. Fertilising provided another key benefit; that is to enhance the proportion of desirable pasture species compared to the undesirable Parramatta grass. Humidicola composed 93% of the pasture in the fertilised area, compared to 40% in the unfertilised area, and well below 20% in the unfertilised unstocked area (Figure 2). Parramatta grass was almost non-existent in the second year of grazing (summer 2016). Subsequently in August 2017, Parramatta grass accounted for 2.8% of the fertilised pasture, compared to 6.5% in the unfertilised and 50% in the unstocked and unfertilised area (Figure 2). Ensuring grazing animals have access to pastures containing weedy Sporobolous spp. grasses seems to be another important factor when aiming to reduce the proportion of these grass weeds in a tropical pasture. Eight of the cattle were sold in early 2017, reducing the stocking rate by half which may have helped the Parramatta grass to increase in numbers between these seasons. 99

There was concern that cattle would overgraze the fertilized site due to both areas being in the same paddock, and so reduce any chance of the improved pasture species out- Page

competing the Parramatta grass. However, humidicola and Wynn cassia not only maintained their plant population and dry matter yield, but the percentage of each improved in the second year (Reeve 2015).

Figure 2 .The amount (percentage dry matter) of the major pastures plants, Parramatta grass and other weeds for the fertilized grazed, unfertilized grazed and unfertilized, unstocked areas at Byfield in 2017. Improvement in pasture quality is another benefit of fertilising pastures containing weedy Sporobolous spp grasses. Both crude protein and digestibility of the pasture was improved with fertiliser, especially during the summer growing season (Figures 3 and 4). However improved protein levels also seem apparent into the dry season (Figure 3).

Figure 3. The crude protein for the fertilized and unfertilized grazed blocks from May 2016 100 to August 2017.

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Figure 4. The digestibility for the fertilized and unfertilized grazed blocks from May 2016 to August 2017.

DISCUSSION

Two key outcomes have been demonstrated by this project. The first demonstrates benefits of fertiliser, particularly when it includes nitrogen, on improved grass in locations with greater than 900mm rainfall. For every kilogram (kg) of applied nitrogen, two to five kilograms of live-weight gain is generated (Reeve and Shore 2013). Therefore for the same area of improved grass two and a half times more grazing can be generated. The key to this response however, is the pasture must be based on improved grasses (Reeve and Shore 2013). For a grazier, other important benefits include; convenience, reduced dependence on purchased feed and reduction of demands on time. The annual fertilizer application for a small to medium landowner might only take one day a year. The second key outcome is the knowledge of effective, non-chemical techniques for the control of weedy Sporobolous spp. grasses. Ensuring grazing animals have access to paddocks with weedy Sporobolous spp. grasses seems to be an important non-chemical control technique. When fertiliser is also added to paddocks with grazing animals, a further reduction in weedy Sporobolous spp. grasses can also be generated. The particular level of fertilizer used here was chosen being the uppermost and practical amount of fertilizer based on measured responses from past research. However, there is always the potential for investigations into different rates of fertiliser especially for range of seasonal conditions, or other soil types. While applying flupropanate based herbicide to control weedy Sporobolous spp. grasses is effective, there are some aspects to consider. Firstly while aerially applying this herbicide is efficient and effective, it can be costly, at about $250/ha. Cheaper application

techniques are available, however equipment requirements, time commitments and 101 paddock accessibility all need to be evaluated. Second, due to the unusual mode of action compared to other herbicides, results from granular flupropanate can be variable (Reeve Page

et al 2015). Thirdly, application to the whole paddock (as opposed to spot spraying) results in a 120 day grazing withholding period after application. Fertiliser on the other hand, while also expensive (our fertilizer costs were $300/ha), provides a number of benefits to both pasture composition and animal performance. If other desirable pasture species are present, substantially higher pasture yield and hence competition to weedy grasses can be generated. This higher pasture yield, together with higher pasture quality, can drive significantly higher stocking rates and animal live-weight gain. While we were unable to directly measure, it’s also presumed that the palatability of fertilised weedy grasses is higher, which leads to an increase in grazing pressure on these species reducing their ability to dominate the pasture and or recruit from seed. The outcomes of this project provide local government pest officers, and landowners, another tool for the cost effective control of weedy Sporobolous spp. grasses. This fertilizer strategy has high applicability to the new landowner, typically with smaller land parcels, who is looking to his local government officer for advice about weed control. Landowners, even with small areas, appreciate the time and cost benefits of not spot spraying with herbicide and enjoy watching their pastures (and stock) flourish after fertiliser application. It is not envisaged that fertiliser will be used across extensive areas as aerial application of herbicide could be more cost effective but economic assessment needs to be conducted on a case-by-case situation. Unfortunately service providers may be unaware of the past research that developed the relationship of nitrogen fertilizer to live-weight gain due to livestock industry fluctuations over the last 20 years and the focus on whole of catchment and larger scale grazing. We believe these research findings need to be extended to current advisors as a matter of priority.

CONCLUSION

We have investigated a non-herbicide control option (fertiliser) that specifically focused on the use of cattle to actively eat weedy Sporobolous spp. grasses at two different locations over 4 years. These invasive plants are very difficult for landowners to control and so have been a source of frustration for those committed to weed control. While fertiliser improves pasture growth, acceptance by stock and so can reduce the amount of weedy Sporobolous spp. grasses in a tropical pasture, it’s highly unlikely this management option will replace the use of herbicide. Hopefully in the future there will be a combination of biological control, herbicide, livestock and land management options where weedy Sporobolous spp. grasses are a major limiting factor to grazier’s ability to remain productive and enjoy where they live.

ACKNOWLEDGEMENTS

We would to thank Dr Steven Bray, Jordon Slarke, Debra Corbet and Madonna Hoffman 102 for their tireless support for this project over 4 years. We would like to particularly thank Leisa Childs from Livingstone Regional Council for her support in securing the finances Page

required for this on farm demonstration, and to Granular Products for supplying herbicide for these trials.

REFERENCES Reeve, J., Shore, B. (2013). Does fertiliser have a role in controlling Giant Rat’s Tail grass and other weeds in pastures in coastal central Queensland? (12th Queensland Weed Symposium). Reeve, J., Cawthray, B., Hopkins K (2015). The effect of grazing on fertilized Sporobolous spp. in Central Qld: the first Year of Results. (13th Queensland Weed Symposium)

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TESTING THE UTILITY OF NOVEL, PRE-EMPTIVE SURVEILLANCE TECHNIQUES TO ACHIEVE EARLIER DETECTION OF FIVE HIGH-RISK WEEDS.

Steve Csurhes, Duncan Swan, Matt Ryan and Lyn Willsher Biosecurity Queensland, Queensland Department of Agriculture and Fisheries, GPO Box 267, Brisbane Qld 4001.

ABSTRACT

Early detection is a critical pre-cursor to successful eradication of potentially serious weed species. Rather than relying only on traditional passive forms of surveillance, such as public awareness campaigns, a targeted, pre-emptive approach is currently being explored to achieve earlier detection of five high-risk weed species currently absent or rare in south-east Queensland, namely: Tropical soda apple (Solanum viarum), Miconia (Miconia calvescens), Cecropia (Cecropia peltata/palmata complex), Karroo thorn (Vachellia karroo) and Siam weed (Chromolaena odorata). Pathways analysis was used to understand dispersal vectors and to predict places where target species are perhaps most likely to be found. Since flying foxes are known to be a primary dispersal vector for Cecropia (and to a lesser degree Miconia), three flying fox camps on the Gold Coast were selected as ‘sentinel sites’ and the understorey beneath the bats will be searched for these species each winter. Similarly, since cattle are the primary dispersal vector of Tropical soda apple and Karroo thorn, a sentinel site used to dump the stomach contents of millions of cattle from across Queensland is being searched each year. Sentinel sites associated with movement of military equipment will be searched for Siam Weed. A network of volunteer weedspotters, numbering over 1100 people, is being utilised to reinforce this pre-emptive surveillance capacity. There is also future scope to explore emerging eDNA technology to detect the pollen of high-risk weed species. If the concept is successful, it will be applied elsewhere in the State.

Keywords: invasive plant, surveillance, early detection, biosecurity

INTRODUCTION

The number of invasive plant species in Queensland increases each year. While most species are relatively benign, certain species become major pests, causing significant damage to grazing land and native plant communities. Much like dealing with skin cancer, prevention and early detection are cost-effective responses and well-worth pursuing. Thousands of potentially invasive plant species from around the world have been subject to a 104 process of ‘weed risk assessment’ in an effort to select species that are most likely to cause the greatest damage in Queensland. A range of so-called ‘high-risk’ species have been

targeted for pre-emptive bans on sale, since many are currently sold as garden ornamentals Page

overseas. In addition, these species are targeted for surveillance and early detection. If detected early enough, when populations are still very small, complete eradication may be feasible. However, early detection of targets in a state the size of Queensland is challenging. Traditional forms of surveillance can be described as passive, generally relying on a range of public awareness material, from fact-sheets to media releases, designed to encourage reporting. While this approach has been successful, and needs to be continued, a number of much more targeted and “active” forms of surveillance are currently being explored, namely sentinel sites, trained volunteer weedspotters and eDNA. Sentinel sites have been utilised in other areas of biosecurity, primarily to detect diseases and pests affecting crops and livestock. However, their application to invasive plants has not yet been tested. This paper discusses the utility of several pre-emptive surveillance techniques applied for the first time to five high-risk invasive plant species in south-east Queensland.

METHODOLOGY AND DISCUSSION

Target selection and pathways analysis

A process of evidence-based weed risk assessment has previously identified a number of high-risk weed species currently absent or rare in south-east Queensland. A decision was made to focus attention on five species in particular: Tropical soda apple, Miconia, Cecropia, Karroo thorn and Siam weed. These species are all major pests overseas and worthy targets for early detection. There is also a wealth of published information on their dispersal history overseas and interstate. This information can be used for so-called ‘pathways analysis’, a process to understand and predict invasion pathways for particular pests. If there is a repeated historical pattern of dispersal and invasion elsewhere, it seems reasonable to predict the same process will occur in Queensland. In simple terms, once we understand how a pest is dispersed across borders, we can focus surveillance at locations where it is most likely to be found – so-called sentinel sites.

Sentinel sites

In the case of Tropical soda apple, we know from experience in Florida and New South Wales that cattle are a primary dispersal vector. Cattle readily consume the plant’s fruit and pass the seeds in their waste. Hence, it makes sense to target places where there are large numbers of cattle, such as saleyards and abattoirs. In this case, a decision was made to target a site used to dump abattoir waste (stomach-contents) of millions of cattle from across Queensland and interstate. The site, near Ipswich, is unique, in terms of the number of cattle involved, and will be searched each year for Tropical soda apple and Karroo thorn, another high-risk species known to be readily dispersed by cattle. Karroo thorn is much like Prickly acacia (Vachellia nilotica subsp. indica), one of Queensland’s worst weeds. It grows faster than Prickly acacia, has larger thorns, produces more seeds and is a dominant plant species across large areas of its native range in Africa. 105

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In the case of Cecropia, flying foxes are an important dispersal vector. Hence, it makes sense to target the understorey beneath flying fox camps for surveillance. In consultation with the City of Gold Coast, three large roosts on the Gold Coast have been selected to test the concept. These sites will be searched for Cecropia and Miconia (another species dispersed by frugivores) each winter. Preliminary searching to-date has not detected any target plants, which may provide a level of confidence that these weed species are either absent or very rare in surrounding areas. We are confident that flying foxes can carry the seeds of various weed species back to their overnight roosts, as the area directly beneath roosting bats is heavily invaded by Queen palms and Umbrella trees, two invasive plant species common in nearby areas. In addition, searching flying fox camps in north Queensland has detected Cecropia before (M. Graham pers. comm). In the event that a target species was detected beneath a flying fox camp, the challenge is then to find the source population. Flying foxes can forage up to 25 km away each night but one study in south-east Queensland found mean foraging ranges in the order of 0.9 – 7.7 km per night for Black flying foxes (Field et al. 2015). While it is not feasible to search such a large radius, we could readily deploy traditional passive surveillance in nearby areas, including media releases in local papers and active searching of high-risk bushland reserves and gardens (eg. local plant collectors). Importantly, the concept of pre-emptive surveillance is a useful “vehicle” to generate interest and attention on emerging weed threats, particularly in various forms of media, including social media, thereby enhancing passive surveillance.

Similarly, the dispersal of Siam weed has in the past sometimes been associated with movement of military equipment. Hence, it makes sense to establish sentinel sites at key military installations in south-east Queensland and to search these sites each year. To-date, sites have not yet been searched but planning is well underway and sites will be targeted for inspection at the peak flowering time next winter.

Volunteers and ‘citizen science’

The use of volunteers in the form of a ‘weedspotter network’ is now well established and working very well. A project led by the Queensland Herbarium (Melinda Laidlaw) and co- funded by Biosecurity Queensland and Local Governments, now has over 1100 trained volunteers searching for high-risk weed species and will greatly improve the probability of early detection. As a side, the use of volunteers and sentinel sites is also being explored to detect Asian spined toads, a potentially invasive species with features very similar to the infamous Cane toad. eDNA

A cutting-edge form of pre-emptive surveillance involves the use of eDNA technology to detect trace levels of a particular target species. In the case of plants, it is conceivable that the technique could be used to detect pollen of high-risk weed species. While pollen can

travel considerable distances, a process of triangulation might be possible to pin-point pollen sources, similar to the process used in north Queensland to track Asian honey bees back to 106 their hives. Recently, eDNA technology has been applied to detect the DNA of Red-eared slider turtles in south-east Queensland waterways and to detect the planktonic larvae of Page

Asian green mussels at Weipa. While pin-pointing the sources of eDNA are challenging, the concept also has merit in terms of establishing so-called ‘proof of freedom’ (i.e. generating evidence that a particular target pest has been eradicated from an area). This technology has significant application in biosecurity and environmental monitoring generally. Exploratory work for high-risk weeds is planned for next year.

Shared responsibility

A key concept in the Queensland Biosecurity Strategy and elsewhere is ‘shared responsibility’. Surveillance in particular is one aspect of biosecurity that can become much more effective if it involves a network of people outside government. The challenge is to communicate the risk posed by potentially invasive pests in such a way as to motivate and inspire others to help. Social media has emerged as an excellent way of establishing groups of like-minded people and communicating with them at low cost. Other environmental initiatives such as the ‘Richmond Birdwing Conservation Network’ show how a group of people can make a difference. By sharing photos and success stories with others, interest and motivation can be maintained, building momentum towards a specified objective. It is planned to explore the use of groups on social media to achieve pre-emptive surveillance for five high-risk weeds species (and certain high-risk animals such as Asian spined toads and exotic snakes), perhaps targeting groups such as plant collectors and ‘Land for Wildlife’ members, who are likely to be “sympathetic to the cause.”

CONCLUSION There is considerable scope to explore novel forms of pre-emptive surveillance. Only time will tell how effective these new options will be. If the proposed surveillance outlined in this paper gains momentum and is maintained over a number of years it will be interesting to see how detection rates at targeted sentinel sites compares to detection rates generally (i.e. will the use of sentinel sites, volunteers etc. achieve earlier detection?). It seems reasonable to assume that increased active surveillance will enhance broader passive forms of surveillance and that a certain level of synergy will develop. Hopefully, potentially serious invasive pests can be detected before they become intractable problems.

ACKNOWLEDGEMENTS

The ‘Invasive Plants and Animals’ (IP&A) Program within Biosecurity Queensland is co- funded by State and Local Governments. Sentinel sites for Cecropia and Miconia have been established in cooperation with the City of Gold Coast. Sentinel sites for Siam weed will be established in partnership with the Department of Defence.

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REFERENCES Page

Field, HE, Smith, CS, de Jong, CE, Melville, D, Kung, N, Broos, A, Thompson, J and Dechmann, DKN (2015). ‘Landscape utilisation, animal behaviour and Hendra virus risk’, EcoHealth, International Association for Ecology and Health, published online 24 September 215 at: https://www.ncbi.nlm.nih.gov/pubmed/26403793

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UAV’S – A SNAZZY TOY OR A REAL SOLUTION FOR AERIAL WEED SURVEILLANCE

Jochem van der Reijden

Biosecurity Queensland, Department of Agriculture and Fisheries,

PO Box 652, Cairns, Queensland 4870.

ABSTRACT The National Four Tropical Weeds Eradication Program (NFTWEP) has been conducting aerial surveillance for Miconia (Miconia calvescens) in the vast rainforests of Tropical North Queensland for many years. Due to safety concerns, manned low level flights are no longer used by the Program. A number of different methods have been tried to replace the manned flights, some with success and some without. From drones to cameras attached to aircraft, each method presents with its own set of problems and results. This paper will look at the past and present in locating Miconia using aerial surveillance and whether UAVs are a real solution to locate this invasive weed. Keywords: UAV, Miconia calvescens, aerial surveillance, weeds.

INTRODUCTION Aerial surveillance using rotary wing aircraft (Helicopter) for Miconia has been conducted by the Department of Agriculture and Fisheries (DAF) since 2007 (DPIF, 2007. 4TW Annual report 2006-2007). Large Miconia plants (over 2 m in height) can be detected from the air by identifying the unique large, ovate leaves with distinct venation of the leaves. Aerial surveillance with helicopters for the detection of Miconia has also been used successfully in the Hawaiian Islands. The inherent risk when using helicopters during low level Miconia surveillance is high. The terrain that typically hosts Miconia is undulating and consists of deep gullies and steep hills, swathed by dense tropical rainforest, including canopy emergent trees. Hills and mountains also act as obstacles that influence wind flows and can cause severe turbulence (Australian Transport Safety Bureau). Pilots who fly in these conditions operate at their maximum ability in order to safely navigate the terrain. DAF suffered two serious helicopter crashes during surveillance activities in 2010 and 2015. These incidents prompted the investigation into alternative aerial surveillance methods for Miconia to eliminate the risk posed to staff. Since2012 the NFTWEP has trialled numerous recognized aerial surveillance methods and investigated a number of untested methods. Each of these methods is explained in this paper and the advantages and disadvantages

of each method analysed. 109

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Helicopter surveillance (2007-2015) Helicopter surveillance for Miconia is typically conducted in the cooler time of the year due to better helicopter performance and more favourable weather conditions. The type of aircraft used in the past has varied and was often guided by advice DAF received from commercial providers. However overtime it became clear that very few makes of helicopter were suitable for use, as they were typically underpowered and not suited to the strenuous conditions in the typical Miconia terrain. The most suitable type of aircraft that has been used by the Program was a Eurocopter Squirrel AS-350. This helicopter type has sufficient power to operate under the given conditions. During operations aircraft were staffed with two spotters in the rear of the aircraft and a navigator in the front. The role of the spotters, as the name implies, was to spot weeds and alert the pilot and navigator. The navigator was in charge of the overall surveillance and directed the pilot when to turn/stop/hover. The navigator also acted as an additional pair of eyes to look out for obstacles (trees, infrastructure and animals). The pilot was in charge of the operation of the aircraft and safety of the passengers and followed direction when plants were spotted by staff. The advantages and disadvantages are listed in table 1. Table 2. Advantages and disadvantages of helicopter surveillance Advantages Disadvantages • Yields good results • Safety issues • Locations recorded are accurate • Requires extensive planning pre-operation • Can send teams out to treat within • Average detection rates (50-60%) days • Utilises a lot of field staff and management • Increased confidence in loci during the peak field season delimitation ensured program progress towards eradication • No photo/video record of surveillance (for review)

Ground Sampling Distance (GSD) Before explaining the alternative surveillance methods it is worth mentioning the importance of the Ground Sampling Distance (GSD) when it comes to aerial photography and identifying features in the images. GSD is most easily explained by how many centimetres (cm) a pixel covers on the ground. As an example, if the GSD is 30cm/pixel it means that a pixel on your image represents 30cm x 30cm on the ground. The higher the value of the GSD the lower the spatial resolution is of that image. This is only one of many variables that influence image quality but a good measure for successfully detecting Miconia. Testing of a suitable GSD for Miconia revealed that a GSD of ≤ 1.2 cm/pixel was needed to positively identify Miconia (Merz et al. 2016), however a UAV trial for detection of Miconia in Hawaii put the GSD at ≤2cm/pixel (Perroy et al. 2017).

UAV – CSIRO (2012-17) From 2012 the Program was involved with a CSIRO project, initially called Project ResQu. Initially the project was setup to look at a number of aspects of autonomous flight using a UAV (unmanned aerial vehicle). The Miconia project was chosen as it provided researchers with the challenging terrain and detection issues as well as the safety aspects that autonomous flights could provide. The UAV platform used was complex and had a number of built in technologies that included an obstacle and aircraft avoidance system as 110 well as an autonomous emergency landing system (Australian Research Centre for Aerospace Automation). Secondary to the flight system, photo analysing software was

developed to inspect the georeferenced images that the UAV collected during flight. A Page

number of successful test flights were conducted at El Arish and Harvey Creek where plants were detected using the UAV technology. Some of the plants detected during this UAV surveillance had been missed in weeks prior, when a manned helicopter flight was conducted. The testing of the UAV platform continued on through 2015. After the second helicopter incident in November 2015 it was decided that no more manned Miconia surveillance flights were to occur due to the risk it posed to staff. A contract with CSIRO business arm was set up in 2016 to survey 2500 Hectares of specified area, supply of georeferenced images (GSD ≤ 1.2 cm/pixel) and investigate the potential for image recognition software to reduce the overall time spent analysing thousands of images. Due to a number of technical and logistical problems, CSIRO were only able to deliver a small component of the UAV surveillance over a 12 month period. The advantages and disadvantages are listed in table 2.

Table 2. CSIRO UAV surveillance Advantages Disadvantages • Safety, no staff in aircraft at low level. • Limitations imposed by regulatory bodies • Proven technology (Project ResQu) (CASA) – can’t fly beyond line of sight • Evidence of surveillance (images) • Very sensitive to weather conditions • Images are georeferenced • Bac-up UAV not available (initially) • Large number of images to manually look through (~220/ha) • No local sub-contractor to deliver service

Commercial UAV/drone operator A number of small weed infestation sites were tested with the use of a local drone operator. The operator used a commonly available drone in that industry (DJI Inspire II). Two of the sites involved surveillance for Limnocharis (Limnocharis flava) and two other sites were within known Miconia territory. The initial Limnocharis surveillance was undertaken with a video feed from the drone over an agricultural drain and the results were good. Limnocharis was not detected on the video and subsequent ground surveillance confirmed the result. Another Limnocharis surveillance trial was conducted near Mission Beach and an orthomosaic image was created for the purpose of analysis. The result of the orthomosaic image was not suitable for identifying Limnocharis but this issue was overcome by analysing the individual images. During this test, Biosecurity Officers were able to positively detect Mexican Bean Tree (Cecropia spp.) another weed in the tropics targeted for control, but the GSD was insufficient to detect Limnocharis. A Miconia survey in Kuranda was completed in a small area (4 Hectares) with good access. The survey results (image quality and coverage) were good and no Miconia was detected which was confirmed by ground survey. The second Miconia surveillance at Mungalli proved more challenging for the operator due to the extremely steep terrain and more difficult access/launch locations. Due to height restrictions in the drone software, the operator was unable to fly closer to the canopy. This resulted in a GSD that was too large for positively identifying Miconia. The advantages and disadvantages are listed in Table 3.

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Table 3. Commercial drone operator Advantages Disadvantages • Safety, no staff in aircraft at low level • Limitations imposed by regulatory bodies (CASA) – can’t fly beyond line of sight • Evidence of surveillance (images) • Sensitive to weather conditions • Images are georeferenced • Limited range (suited to small areas only) due to limited battery life • Cost is too high if scaled up

GPS referenced camera In mid-2017 a proposal was put together to try an action style camera mounted on a full size helicopter and run a number of trials to determine the suitability of this camera for the detection of Miconia. These trials are currently being conducted using a GARMIN VirbXE action camera attached to a Eurocopter Squirrel AS-350. Although incomplete the initial trials have been promising with images of a suitable quality and GSD captured. Further larger scale testing and ground truthing will determine if this method is suitable for detecting Miconia in difficult terrain.

CONCLUSION Although technology is advancing quickly and the use of UAVs has become widely used in the field of Natural Resource Management, it is important to identify the needs and look at the limitations of the technology before fully committing to UAVs. While UAVs are a snazzy toy, we have found that for the purpose of large scale Miconia surveillance they are currently unsuitable. The challenging terrain and large surveillance areas present the biggest problems for UAVs and the CASA regulation regarding the operation of these machines is strict and prevents beyond line of sight operations. Perhaps within a few years the technology and legislation will meet the Programs demands. The NFTWEP is currently in the process of further testing GPS referenced camera technology and liaising with companies specialising in aerial photography from fixed wing aircraft.

REFERENCES Australian Research Centre for Aerospace Automation. ‘ResQu’. http://www.arcaa.aero/projects/completed-projects/resqu Australian Transport Safety Bureau. ‘Mountain wave and associated turbulence’. https://www.atsb.gov.au/publications/2009/mountain-wave-and-associated- turbulence. (Australian Government). Merz, T., Hrabar, S., Kendoul, F. and Jeffery, M. (2016). Unmanned helicopter system for Miconia weed surveys. Twentieth Australasian Weeds Conference (2016) 191-194.

Perroy, Ryan L., Sullivan, T. and Stephenson, N. (2017). Assessing the impacts of canopy 112 openness and flight parameters on detecting a sub-canopy tropical invasive plant using a small unmanned aerial system. ISPRS Journal of Photogrammetry and Remote Sensing

125: 174-183. Page

BITOU BUSH SURVEILLANCE UAV TRIAL

Stacy Harris¹, Peter Trotter² Felipe Gonzalez3, Juan Sandino3

¹Biosecurity Queensland, Department of Agriculture and Fisheries, Nambour QLD 4560 ²Aspect UAV Imaging, 16 Spoonbill Street Peregian Beach QLD 4573 3Queensland University of Technology, 2 George Street, Brisbane City, QLD 4000

ABSTRACT (SUMMARY) Bitou bush (Chrysanthemoides monilifera sub-species rotundata), a native of South Africa, has the ability to outcompete and smother native coastal dune vegetation. Infestations in Queensland have been dramatically reduced since the 1980s, with only isolated plants being found in the field today. Ground surveillance is currently carried out twice yearly involving teams of field staff surveying densely vegetated areas in an emu parade to maximise detection of both mature plants and seedlings. Some of the coastal vegetation has become too dense making it nearly impenetrable for ground surveillance. The risk of not detecting plants in this area has become high due to lack of visibility. Another technique of monitoring and detection is required to ensure eradication. This project aimed to develop a surveillance protocol and strategy using unmanned aerial vehicles (UAVs) also commonly known as drones to become a permanent component of the Bitou bush eradication project. An innovative company, Aspect UAV Imaging, worked with Biosecurity Queensland to develop suitable UAV technology. Test flights were carried out to determine the required camera resolution, the flight height which provided proper resolution and the amount of overlap using a systematic pattern over the test area. Images were processed and enhanced post-flight to aid in the detection of Bitou bush. Ortho- images were georeferenced with colour enhancement and trialled with a series of programs to determine the best application and usability. Images processed by researchers from the Queensland University of Technology using automated classification algorithms gave promising results. With improvements in technology, the regular use of UAVs for surveillance will soon complement many aspects of weed monitoring. Keywords: Chrysanthemoides monilifera, monitoring, survey

INTRODUCTION Bitou bush (Chrysanthemoides monilifera sub-species rotundata), a native of South Africa, is a perennial shrub growing up to 5 meters tall with yellow chrysanthemum-like flowers. It grows quickly, produces large numbers of seeds and is able to outcompete and smother native coastal dune vegetation. In Queensland, Australia the coastal zones under threat 113 are of high conservation and tourism value. Some areas under immediate threat are world heritage listed. Bitou bush has been recognised as a Weed of National Significance. In Page

New South Wales, Bitou bush is out of control and has degraded over 60% of the coastline (Willsher 2016).

History Bitou bush was declared a pest plant under Queensland legislation in 1981. When control work began in the early 1980s, there were roughly 700 hectares of Bitou bush scattered along the southern Queensland coast. Over the past 30 years, a multi-agency coordinated control project has evolved to manage Bitou bush infestations from Bundaberg to the Queensland/NSW border. Infestations sizes have been dramatically reduced, with only isolated plants being found in the field today. Although eradication from Queensland is the ultimate goal, it is recognised that preventative surveillance will need to be carried out on an indefinite basis to prevent reinfestation. The seeds of Bitou bush are dispersed by birds and ocean currents, meaning Queensland’s southern coast will remain under threat from reinvasion from infestations in NSW (Willsher 2016).

SURVEILLANCE Surveillance is carried out to coincide with flowering in May and later in the year in September as plants left for longer than six months can significantly contribute to the seed bank. The multi-agency coordinated program run by Biosecurity Queensland includes stakeholders from local governments, Queensland Parks and Wildlife Service (QPWS), the Department of Natural Resources and Mines (DNRM) and other Landcare agencies who work together to battle through the dense vegetation in an effort to eradicate Bitou bush. Ground surveillance Ground surveillance involves teams of field staff surveying densely vegetated areas in an emu parade spaced at intervals of up to 10 meters apart. All plants located are mapped and treated during the survey period. Historical distribution data is uploaded onto GPS units for staff to refer to in the field during survey work. The dataset enables staff to locate and check historical sites at the montioring time and record new tracks and finds throughout the survey. Lyn Willsher (Biosecurity Queensland) Detection of Bitou bush in thick coastal vegetation is difficult and obstacles such as brown snakes add to challenge. . In order to deliver the required eradication outcome other methods of detection are essential to compliment and guide the work of ground crews.

Aerial surveillance Helicopter surveillance is a critical component of the project and is carried out over parts of the project area annually. Aerial surveys aim to delimit high risk areas outside of known distributions to confirm that these sites are clean and do not support infestations. Aerial surveillance is expensive and conditions need to be ideal for detection to be successful. When new pilots are engaged, it can take several hours in contracted time for 114 them to grasp the technique required for detecting Bitou bush and master the search patterns required. Surveillance is done without doors and with two spotters on each side of the rear of the helicopter (AS350 Squirrel) and another spotter in the front of the aircraft, Page

responsible for recording data points and assisting the pilot with obstruction avoidance. Light levels and weather are huge factors that affect the success of the aerial surveillance. UAVs (Unmanned Aerial Vehicles) The aim of this project was to develop a surveillance system that uses unmanned aerial vehicles (UAVs).with the intention that they would be safer, more affordable, efficient and effective than helicopters. An image created and developed could be thoroughly inspected by an experienced Bitou bush spotter on a computer regardless of weather conditions. UAVs are regulated by the Civil Aviation Safety Authority (CASA) .The UAV pilot is required to have a Controller’s Certificate appropriate to the UAV being flown and commercial operations are carried out under an RPA Operator’s Certificate. Testing The first test took place in April 2016 with Nathan Roy from Aerobugs and the author using a 3DR solo™ UAV and a GoPro™ 4+. The UAV was flown over part of a 160 ha area of impenetrable vegetation between Rainbow Beach and Inskip Point in a zig-zag pattern and still photographs were collected at intervals. The images were viewed in “real-time” on a tablet in the field day although at times it was difficult to observe the footage due to the glare on the screen. The footage was recorded and the resolution of the still photos when viewed on a computer was excellent and Bitou bush plants would be easily identified. Using UAV’s to capture images for desktop surveys was feasible, but there were still issues to overcome. Challenges The first challenges were to determine the required camera and image resolution; the flight height required and the amount of image overlap using a systematic pattern over the test area. Images needed to be georeferenced so GPS coordinates could be extracted when a plant was located. Next was to stitch multiple images together (ortho-image) instead of looking at thousands of individual photos. Once an ortho-image was developed a grid would need to be overlayed so that, when carrying out computer surveillance, the viewer wouldn’t get lost in the image and could reference where they were up to at any given time. Other challenges in using UAV’s included; a short battery life (20 minutes); weather and light conditions; survey coverage and the time take to view images after capture Trials After the first test using a 3DR solo™ and GoPro™ camera, a second trial was carried out with Aspect UAV Imaging. The aim was to try to overcome the many challenges. For the second trial flown on 14th November, a Bitou plant (affectionately referred to as “Betty”) detected by ground surveillance was marked with a GPS and left in the field so the UAV could fly over the plant and capture images. This was one of the issues with the trial as there are very few flowering Bitou bush plants left in Queensland, but was essential to confirm detection of Bitou bush using a UAV in the field. Images of the plant were taken at heights from 10 to 40 meters above ground level. The UAV used was a DJI™ Phantom 4 which has a 1/2.3 CMOS, 12.4 megapixel camera. A third trial again with Aspect UAV Imaging was run in May 2017 with a test site of approximately 100 x 200 meters on the coastal dunes between Inskip Point and Rainbow Beach. A DJI™ Phantom 4 Pro UAV with a 1-inch 20 megapixel camera was used. The flight was planned using DroneDeploy. The area was flown in two flights with different

heights above the launch point of the first dune. Two flights were required to allow for the 115 effect on image overlap caused by a gradual increase in terrain elevation from the launch point going inland. There was a slight overlap between the two flights. Page

Table 1. Key flight parameters

Height 20-30 meters above ground level

Overlap 85% forward and 85% side overlap between images Area covered Approximately 100 meters by 200 meters

Number of images 816

Resolution Approximately 1 – 2 cm/pixel Flight time Approximately 32 minutes

A fourth trial was run on 12 July 2017 at Kingscliff, NSW. This site was chosen because of the ready availability of Bitou plants. The objective of this trial was to gather images of both flowering and non-flowering Bitou bush and conduct a digital processing of the pictures using an automated classification algorithm. These algorithms are being developed by researchers at Queensland University of Technology (QUT) and provided significant enhancement of the images to show the particular target species. Post flight processing Second trial The known Bitou bush was able to be seen in the images but was difficult to distinguish from surrounding vegetation. Third Trial The images produced from the third trial were to be processed and enhanced post-flight to aid target detection. Ortho-images were georeferenced to extract coordinates. The images were then trialled with a series of programs to determine the best application and usability. Processing was done using two online services DroneDeploy and Propeller. A link was provided to give access to the computer surveillance operator to view the images. These services do not provide indefinite storage of these processed images so the key output was downloaded and provided on a USB. These ortho-images may be opened and coordinates extracted using free open source software called QGIS. One of the key features of the trial was to use an image viewing program that was easy for the computer surveillance operator to use as operators may not necessarily have GIS training. Fourth Trial The images from the fourth trial contained many known Bitou bushes, so these images were used as a trial of software from Queensland University of Technology (QUT). This software uses automated classification algorithms to identify the target species. Images were gathered at various heights and several rotation changes in a survey pattern at Kingscliff in northern coastal NSW where there is a high concentration of Bitou bush plants. QUT developed and trained a software package to read RGB digital image files and output highlighted regions of the weed in the studied area as illustrated below.

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Figure 8 . Output images at various altitudes and rotations. (a) 20m. (b) 30m. (c) 20m. (d) 30m

The resulting image shows how Bitou bush regions were segmented against other green vegetation, which is a very positive result. Nevertheless, the proposed detection method requires a large training data set to achieve outstanding segmentation and validate its robustness against unknown data. This training step is known by marking Bitou bush manually onto a set of images. Table 2 shows the accuracy of the technique. Table 2. Accuracy of the proposed detection algorithm.

Altitude Bitou bush Background Accuracy Set (m) True positives False positives True negatives False negatives (%) 1485 521 13682 899 1 15 91.44 74.03% 25.97% 93.83% 6.17% 1985 748 12731 1123 2 15 88.72 72.63% 27.37% 91.89% 8.11% 694 243 14953 697 1 20 94.33 74.07% 25.93% 95.55% 4.45% 673 262 14871 781 2 20 93.71 71.98% 28.02% 95.01% 4.99% 137 39 15930 481 1 30 96.87 77.84% 22.16% 97.07% 2.93% 173 32 15978 404 2 30 97.37 84.39% 15.61% 97.53% 2.47%

Each extracted sample per image was labelled according to the output of the algorithm.

True positives (TP) corresponded to samples that were correctly classified as Bitou bush; true negatives (TN) for the ones classified properly as background; false positives (FP) for 117 samples that were wrongly classified as Bitou bush; and false negatives (FN) for Page

incorrectly classified background samples. Based on a total of 16,587 extracted samples per image, accuracy was defined by Equation 1.

TP + TN Accuracy = *100 TP + TN + FP + FN It was found that accuracy values showed an incrementing pattern while analysing images at higher altitude levels. This occurred because, at high altitudes, fewer data (colours, texture properties) need to be classified as shown by the amount of Bitou bush samples. Conversely, at low heights, more image details must be read and analysed to perform a classification task. Those details might include a natural overlay of other plant species such as grass, other weeds, and soil. Depending on the needs and type of output data, these accuracy indicators would require further analysis. It is recommended, therefore, to perform mission routes at medium heights (e.g. 20 – 25 m) in order to conserve a balance between single location and quantification of the invasion of Bitou bush in a studied area. Ultimately, further work is being done to improve the accuracy of the algorithm and understand the capabilities and limitations of this process.

CONCLUSION This trial has progressed rapidly from a single flight to capture and inspect images using an off the shelf drone to an investigation of the capabilities of state of the art software. The first and second trials demonstrated that Bitou bush could be seen in images taken from a UAV at heights up to 40 meters but was difficult in distinguishing from surrounding vegetation. The third trial showed that images, obtained using an off the shelf UAV flown at 30 meters above the terrain, with no image enhancement, has sufficient image definition for an experienced person to identify a Bitou bush provided surrounding scrub does not hide it. This process can potentially replace ground surveillance by teams with office-based surveillance of images. However, a detailed study of thousands of images by a person is not sustainable. A process that automates and highlights the target species is highly desirable. In the fourth trial, the developed detection algorithm outputted remarkable results by highlighting Bitou bush leaves amongst a set of diverse natural vegetation species in Kingscliff, NSW. Nonetheless, further work is needed to improve the quality of the training dataset to improve accuracy. Moreover, the proposed technique requires additional tests to improve its robustness against illumination changes, image sharpness and presented noise, as well as checking their outputs at differents sites, using a higher resolution camera and the ability to detect younger bushes.

REFERENCES Department of Agriculture and Fisheries (2017). Fact Sheet Bitou bush fact sheet. https://www.daf.qld.gov.au/__data/assets/pdf_file/0018/61344/IPA-Bitou-Bush-

PP10.pdf (Queensland Government) 118

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Swan, D (2016) Bitou bush Aerial Surveillance Post-Operation Report South East Region 2016, Unpublished internal Biosecurity Queensland report. (Queensland Government) Willsher, L (2015) Bitou bush eradication project report 2015-2016, Unpublished internal Biosecurity Queensland report. (Queensland Government)

WHAT CAN I DO WITH WEED CONTROL DATA?

Brooks1, S.J. Biosecurity Queensland, Department of Agriculture and Fisheries. 1Tropical Weeds Research Centre, PO Box 187, Charters Towers, 4820.

ABSTRACT

There are increasing requirements for local, regional, state and federal organisations to collect, summarise and make decisions on data from weed control operations. This paper provides examples of how field control data can be collected to meet the needs of internal and external reporting. Data summaries can assist with documenting past expenditure or for supporting cases for ongoing or new expenditure. They can also highlight infestations that are well managed or identify problems. Examples are drawn from different types of weeds, single and multiple infestations and across different spatial scales. Reports rely on a consistent measure of what is going on at the site (s) over time and can include trends in plant numbers, treated area, herbicide use or worker effort, over time and over a consistent spatial scale. The difficulties inherent in interpreting or reconstructing past survey and control activities show the importance of considering data collection and mapping processes when management plans are constructed. So that operational records can be summarised to justify and learn from the field activities. Ultimately agencies expend considerable effort surveying, controlling and recording field operations, yet the full benefit of those data are not always seen.

Keywords: weed mapping, weed eradication, weed funding

BACKGROUND

Many years of experience has accrued through reporting on nationally cost-shared ’Siam weed program’ (see Jeffery (2012)) and the ‘Four Tropical Weeds Eradication Program’ (see Jeffery and Brooks (2016)). Unfortunately, many of the data processes from these long-term programs are confined to reports and internal presentations that are not widely accessible. Examples from both programs are used in this paper to present options looking at the principles, requirements and use of field data, with examples of weeds from single known locations and from multiple infestations. Rather than recommending a specific data capture and recording process, this paper presents common themes that could be implemented across different agencies, recording systems and weeds. Funding providers may have different reporting requirements so having a detailed and consistent base level of data can help to adapt to their specific requirements. 119

COLLECTING DATA Page

Those interested in the management of a weed infestation want a consistent measure of what is going on in an infestation (or reporting unit) over time; an overview of useful field data is presented in Table 1. The most important records have a date, location, recording officer and a measure of what weed was there. Ideally, the information should be stored in some kind of secure database that describes the unit and the control revisits to it, with links to geographic information software. The units will need a consistent label and information on their discovery, vegetation and terrain to assist field and reporting activities. While field teams can ‘overdo’ the spatial recording, slowing field activities, it is difficult to know what the initial scale should be, so how and when to add a new point should be considered when planning and reviewing field activities. Aggregating records within certain distances of an existing waypoint is one solution, but it is impossible to go back to a finer scale.

USING DATA

Reporting where it was

Consistent mapping data can show whether the weed is relatively confined or continues to be found in new areas, and also provides an insight into dispersal mechanisms and distances. Table 1 mentions some of the considerations for using spatial data for survey planning, quality control and budgeting. Before reporting on what weeds were present, officers have to decide what scale is most appropriate for their reports. As the dispersal of the weed may be independent of the imaginary boundary lines, the spatial scales used for reporting are not necessarily survey scales. Care needs to be taken that the reporting scale (e.g. waypoints or polygons) is not concentrating or restricting the survey activities. Table 2 presents some of the options for spatial scales used for summarising data and some of their advantages and disadvantages. It is important for most scales that consideration is given to what should constitute a new reporting unit. Except for waypoints (Table 2), the other units are summarised by using all the data from all their points for a particular period of time.

In some cases such as the single location Miconia racemosa and M. nervosa infestations the grid scale opened up more options for consistently comparing field data between years and with other species (Table 3). Prior to 2009, Chromolaena odorata infestations were defined by buffers that had to be redrawn, renumbered and re-analysed every year, this created infestations between 13 and 3000 ha. The overlay of a 1-ha grid layer at least enabled a fixed comparison of the same areas from year to year. Changing the reporting scale can create problems with the analysis of past data on a different scale and the creation of ‘new units’ through finer scale recording. Therefore it is important that the chosen scale can provide the necessary rigour over the life of the project. There are relatively few differences using an infestation basis or a grid system for relatively small and discrete infestations like those of Limnocharis flava.

Reporting what was there

There will be variation in plant numbers or treated areas over different survey dates so it is important to focus reports on the overall trends, rather than a detailed commentary. In addition to showing the rundown of the weeds population, density or extent, consistent 120 records can be used to directly or indirectly study the population over time or seasonal patterns of emergence. Occasionally the removal of mature plants or particular weather Page

conditions/events will bring a flush of plants. In this case, the extent of the infestation is more meaningful than the number of plants. Reports should be based on legitimate comparisons over time and fitted curves have to have a biological significance or relevance.

The assumptions underlying reporting progress towards eradication are built around the time since last plants were recorded. If any plants were found in the last year the unit is in the active control phase. If the records show an absence of plants for the last year the site is in a monitoring phase. After accruing a required length of time in monitoring with absence records the infestation is considered eradicated. For each reporting unit a summary of the last plant data can be plotted as a histogram of the last detection data (Figure 1 a) for a particular point in time. A lot of additional parameters can be calculated from the last detection data including: the percent of control and monitoring, rate of progression to monitoring and the rate of relapse from monitoring to control phase. An alternative to the time since last detection is the time since last reproduction. This is a more flexible measure as it allows for seedling recruitment and the date is reset to zero if there is a mature plant found in the reporting unit. If mature plants are only recorded at the start of the control period or not recorded at all, then the discovery date becomes the time since last reproduction. Some older records and units with only seedlings may not have a last mature plant date, in these cases the discovery date is used and this is why the x-axis of Figure 1b includes reproduction or discovery.

Reporting who was there and what was done

Recording total effort (people by time) can help with budgeting, showing removal progress and acknowledging in-kind contributions. Declining treatment costs can also show weed removal progress, provided the total, area is surveyed and treated. Simple charts can be used to show the amount or proportion of time spent on particular weeds across sites, shires or agencies. The average area covered per worker per day from search and control efforts can also guide future budgets and planning. By combining the search area, search rate and frequency of survey information, an accurate budget or funding submission can be constructed. Over time agencies would want to be searching similar or greater areas and finding fewer weeds, but breaking the search more/find more nexus can only occur over time with consistent spatial and effort records.

Identifying common problems

Officers would usually expect to see a general decline in the measured parameters (e.g. treated area; number of plants) over time. So trends like the repeated treatment of the same or greater areas can indicate that the treatments are not effective or the treatment frequency is too low. Observations of any post-treatment regrowth or data on the re- occurrence of mature plants can help inform these situations. Repeated population spikes could indicate a source of re-introduction particularly if near roost trees or a linear feature like a river where seed or vegetative material is reintroduced into the same suitable habitat.

The discovery of new infestations can be a problem, particularly the continued discovery of a large number or size of infested areas a long way away from known areas. The spatial analysis of the distance between reporting units known up to a year ago to those found in the last year can be quite simple. The discovery of large disparate areas can stretch 121 capped resources to the point where certain infestations are prioritised over others and Page

confidence as to the extent of the incursion, or whether eradication is feasible, starts to erode.

Field records have also been interrogated to show the frequency of visits and whether sites were visited at all. The occurrence of ‘data gaps’ can occur when records where incorrect, collected on a broader scale, points were missed or visits were undertaken by stakeholders with fewer recording requirements. The proportions of infestations without records can be quite informative for internal quality control. By reviewing collected data, officers can also look at how useful the data-recording fields are. There is no point in continuing to collect information that is too inconsistent, incomplete or inaccurate to be analysed.

SUMMARY

There needs to be increased understanding that weed control programs require a longer term commitment than some traditional biosecurity responses or local authorities’ projects. Environmental weed control programs can extend over many years, during which renewed internal or external support will be needed. That support can be conditional on showing that on ground actions are well managed and have reduced the level of weed incursion. Presenting information about the survey area and the effort (not just on the number of weeds) can help show good project governance and that interim progress towards the weeds removal is being made. Besides the differences in weed types, degrees of incursion and reporting requirements, different jurisdictions have different collection processes, technologies and capacities. Despite these differences, this paper highlights some common themes/ and issues for collecting, reporting and summarising field data.

Data recording is always a trade-off between the detail needed to summarise the situation and what is feasible and sustainable in the field over time. The focus should be on the quality of the data that is securely stored, often in a database structure with links to a geographic information system. To report on activities over time then there is a clear requirement for consistency over time, space and personnel, with a view to producing overall trends for funding providers.

ACKNOWLEDGEMENTS

Field and mapping data was collected by many DAF and stakeholder field personnel. Joe Scanlan, Shane Campbell and Wayne Vogler commented on the draft manuscript.

REFERENCES

Jeffery, M. (2012). Eradication: lessons learnt from 17 years of the National Siam weed eradication program. Proceedings of the 18th Australian Weeds Conference, ed. V. Eldershaw. (Weed Society of Victoria, Melbourne). pp. 92-5.

Jeffery, M. and Brooks, S. (2016). Eradication in the tropics: constantly changing and adapting. In: Proceedings of the 20th Australasian Weeds Conference. R. Randall, S. Lloyd and C. Borger, eds. Weeds Society of Western Australia, Perth. pp. 23-7. 122

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Table 1. Overview of the types and uses of weed control data in the field. Category Parameters Use and importance Notes Who Workers and hours Labour will usually be the The amount of weed recorded or biggest cost factor. area searched will reflect the resources used so control data is intertwined with effort data.

What Counts Counts +10% are useful for It doesn’t matter so much if there certain infestations are 10 or 11 plants, but it does matter if there are 9, 90 or 900.

Subsample Alternatives to counts if Whatever is used at the start population thousands of seedlings, a remains applicable as the mass of intertwined vines or infestation runs down. Commonly area of the weed, a paddock of exotic grasses. the initial control information can density of the weed lack the detail present in later records. Photo points can help but weight of weed not for quantitative records over time. amount of herbicide

Absence data Repeated evidence of Essential part of the eradication absence or nil records from programs is recording the absence searches of the entire of plants in previously controlled infested area, crucial to areas. proving that the weeds have been removed.

Number/occurrence Preventing reproduction is Draw survey buffers around and stage of mature important for any weed mature plants. Dioecious weeds plants control program. May need to like Cecropia peltata need a larger reassess survey intervals to search area if male and female prevent seed production. plants are present. Percentages of mature plants has caused problems with data analysis.

When Date Links to all other data fields Daily effort, weed seasonality Where GPSr* waypoint Locations are buffered for The point collection (and naming) target search areas. protocol needs to be sustainable Polygons could also be used. and consistent. Target areas reflect dispersal vectors and distances, also suitable habitats.

GPSr* track files Tracks buffered to determine Relates to labour data and helps searched areas with quality control and budgeting.

Why Weed(s) name or Agencies will have a plan but Resources can be roughly split code the target(s) needs to be between multiple weeds at the 123 recorded against the time, same location on the same day. date and people. Page

Category Parameters Use and importance Notes How Control method or Expense and requirements to Can assist with budgeting and amount of herbicide log herbicide use. documenting the reduction in weed used infestations over time.

*Global Positioning System receiver.

Figure 1. A) Mikania vine time since last detection and b) time since last reproduction or discovery as of June 2017. The reporting unit is a 1 ha cell (management area).

Table 2. Spatial scales that can be used as a basis for reporting of weed control activities. Name and description Pros Cons

Waypoints Directly related to field data Margin for error can lead to confusion and loaded in GPSr over new or existing points, making data individual weed harder to compare over time and locations numerous points.

Polygons Covers all points in an area Narrow focus of the survey and can ‘grow’ individual weed areas Can follow landforms Need some technical support

Lot on plans Usually static and linked to Vary in size and number local government Property boundaries information

Discrete locations small Simpler option to report Need to decide how far apart new patches of weeds along progress infestations are as they can start to merge way apart. Are different sizes

Buffered areas Reporting area most Buffers have to be re-drawn each year, so resembles the search area infestations can be merged and get radius applied to points unevenly large

Grid layer Fixed over time Needs spatial skills to create/manage a fixed layer of cells Links to higher scales of Arbitrary across the landscape so new with the same square reporting (catchment and cells are created easily and weeds occur dimensions overlying regional). anywhere in the cell infestations. Easier to measure progress

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Table 3. Cell counts for selected weed species and the percentage of cells with plants absent for a year or more (monitoring phase) as of June 2017 unless noted. A cell is 1 ha unit of a fixed grid layer that has had a least 1 specimen of the target weed recorded. Clidemi Chromolaen Limnochari Miconia Miconia Miconia Mikania a hirta* a odorata** s flava calvescen nervos racemos micranth s a a a

Cells (ha) 281 8102 71 938 35 46 89 % 31 16 61 52 17 59 70 Monitoring * Data to October 2015 from 2 infestations, ** Data to December 2012.

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SOME RAPIDLY EMERGING WOODY WEEDS IN SOUTH-EASTERN QUEENSLAND

Sheldon Navie The IVM Group, PO Box 545, Varsity Lakes, Queensland, 4227.

ABSTRACT

Recent field surveys have highlighted the fact that several species of emerging woody weeds are becoming naturalised in a large number of conservation reserves in south- eastern Queensland. These observations demonstrate that the same group of species have appeared in numerous reserves in the last 5 years, where they were not previously recorded. While these emerging weeds are not common or abundant enough to be having a significant environmental impact as yet, the rate that they are invading suggests that they could cause significant impacts in the future. These woody weed species include Giant Bird of Paradise (Strelitzia nicolai), Yellow Trumpet Tree (Handroanthus chrysotrichus) and Awabuki Sweet Viburnum (Viburnum odoratissimum var. awabuki).

This paper provides information about the biology and ecology of these rapidly emerging weed species, and highlights characteristics that can be used to simplify their identification. It also gives an outline of their naturalisation history in Queensland, and attempts to explain why they have become so invasive in recent years.

Keywords: woody weeds, emerging weeds, conservation reserves.

INTRODUCTION

Golden Trumpet Tree

Golden trumpet tree (Handroanthus chrysotrichus) is widely cultivated as a garden and street tree in the sub-tropical and tropical regions of Australia because of its attractive displays of golden yellow flowers in spring (Navie 2013a). This rather small spreading tree usually grows 4-10 m tall and is native to South America (i.e. Brazil and north-eastern Argentina).

The leaves of saplings and mature trees have five leaflets that are palmately compound with margins that are either entire or slightly toothed near their tips. The branchlets and leaves are covered in distinctive golden-coloured hairs when young and the leaves of adult trees are shed during winter. The attractive golden yellow tubular flowers are produced in abundance in early spring, before the new leaves develop. They are arranged in dense clusters at the tips of the branches. The fruit is a long and slender capsule (10-40 cm long) which is velvety in appearance due to a dense covering of golden or reddish hairs. Each fruit capsule contains large numbers of papery seeds with transparent wings on either

side. These seeds are easily dispersed by wind movement and may also be spread larger distances in dumped garden waste, by waterand as a contaminate in soil. 126

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Golden trumpet tree was first recorded as naturalised in Australia in 2003, when it was reported to be spreading from cultivation in the grounds of the Bellingen Hospital in northern New South Wales. Populations have also been reported establishing along the edges of conservation reserves in south-eastern Queensland in more recent years.

Awabuki Sweet Viburnum

Awabuki sweet viburnum (Viburnum odoratissimum var. awabuki) is a plant from southern Japan and Taiwan that has also become popular as a garden ornamental in recent years, with a cultivar known as 'Emerald Lustre' very common in cultivation (Navie 2013b).

This small tree has paired leaves with irregularly toothed to almost entire margins that are thick and leathery in texture. These leaves are bright green in colour, with a glossy or lustrous appearance, and the new growth is often slightly coppery tinged. The small, white flowers are produced in branched clusters at the tips of the stems in spring and the small fruit turn from green to reddish or blackish in colour as they mature. They are fleshy but contain a single hard seed in the centre.

This species mainly reproduces by seed, which are thought to be dispersed by birds and other animals that eat the bright red mature fruit. Seeds may also be spread into bushland areas in dumped garden waste or washed down waterways during floods. Awabuki sweet viburnum was first reported becoming a problem in the Coffs Harbour area on the northern coast of NSW in 2010, with control of this species being undertaken in several bushland sites. It also been recorded as a weed in the Wide Bay, Port Macquarie, Sunshine Coast, Gold Coast and Brisbane areas in recent years. Most of the infestations of this species appearing in bushland, currently consist of seedlings and juvenile plants, with relatively few mature plants established at this stage.

Giant Bird-of-Paradise

Giant bird-of-paradise (Strelitzia nicolai) is a large clump-forming plant that resembles a banana tree. It is native to southern Africa but has long been cultivated as a garden ornamental in Australia (Navie 2014). However, it has only recently emerged as a weed of rainforests, open forests, wetlands and riparian vegetation in the sub-tropical and warmer temperate parts of the country.

Giant bird-of-paradise produces multiple woody stems reaching up to 12 m tall. The massive leaves (up to 1.8 m long) are arranged like a fan at the top of the stems and develop a torn appearance over time. The flowers are large (as much as 45 cm long) and borne in clusters in the forks of some of the leaves. They are made up of a large dark blue bract at the base, white sepals and bluish-purple petals that form a “tongue”. These flowers are followed by fruit capsules which split open to reveal three compartments when mature. They contain several black seeds, each with a bright orange woolly aril attached to it, and are probably dispersed by birds and other animals that are attracted by the arils.

The first naturalised record of this species in Australia was in 2001, when several young plants were found growing in rainforest at Mount Nebo north-west of Brisbane. Since then several further populations have been recorded at Mount Glorious and in the D'Aguilar

Range (ALA 2017). More recently, several populations have appeared in conservation areas in Brisbane, on the Sunshine Coast, and on the Gold Coast. 127

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MATERIALS AND METHODS

According to anecdotal evidence, it seems that the species outlined above have become much more prevalent in conservation reserves in south-eastern Queensland in a very short period of time. To determine if this is in fact the case, records of observations and surveys conducted by the author in a number of conservation reserves in south-eastern Queensland between 2010/2011 and 2016/2017 were analysed.

Survey data, reports, and photos from this time period were investigated and the numbers of golden trumpet tree, awabuki sweet viburnum and giant bird-of-paradise plants observed in the reserves was determined. In many cases the exact number of plants seen was not recorded, so it had to be estimated from the data available.

RESULTS

The results of this analysis of survey records is provided in Appendix 1, while a summary of the data for each of the species is provided below.

Golden Trumpet Tree

The data in Table 1 shows that the most golden trumpet tree plants were observed during the 2016/2017 financial year, and this species was also found in the highest percentage of reserves during that period. However, due to the fact that this species was found in relatively few reserves, there was no clear increasing trend in the observational data.

Table 1. Observations of golden trumpet tree in reserves in SEQ since 2010. Year Number of Number of % of reserves Estimate of total reserves reserves where where weed number of plants surveyed weed observed observed observed 2010/2011 11 1 9% 3 2011/2012 5 0 0% 0 2012/2013 3 1 33% 100 2013/2014 8 0 0% 0 2014/2015 - - - - 2015/2016 6 0 0% 0 2016/2017 5 2 40% 120

Awabuki Sweet Viburnum

The data in Table 2 shows that awabuki sweet viburnum was observed in a much greater proportion of reserves in the last two years (i.e. 60-67% of reserves) than it was between 2010 and 2013 (i.e. 0-20% of reserves). A total of 4 plants were observed during 19 surveys between July 2010 and June 2013, whereas about 40 plants were observed

during 19 surveys conducted between July 2013 and June 2017.

128 Table 2. Observations of awabuki sweet viburnum in reserves in SEQ since 2010. Year Number of Number of % of reserves Estimate of total Page

reserves reserves where where weed number of plants surveyed weed observed observed observed 2010/2011 11 0 0% 0 2011/2012 5 1 20% 4 2012/2013 3 0 0% 0 2013/2014 8 3 37.5% 15 2014/2015 - - - - 2015/2016 6 4 66.7% 15 2016/2017 5 3 60% 9

Giant Bird-of-Paradise

Table 3 shows that giant bird-of-paradise was not observed during any survey prior to July 2013. On the other hand, it has been recorded during 5 of the 19 surveys conducted since that time – with over a hundred plants being observed in total. However, examination of the data in Appendix 1 indicates that all of the populations of this weed were recorded from reserves located on the Sunshine Coast or Gold Coast – and no surveys of reserves were conducted in these regions prior to June 2013.

Table 3. Observations of giant bird-of-paradise in reserves in SEQ since 2010. Year Number of Number of % of reserves Estimate of total reserves reserves where where weed number of plants surveyed weed observed observed observed 2010/2011 11 0 0% 0 2011/2012 5 0 0% 0 2012/2013 3 0 0% 0 2013/2014 8 2 25% 22 2014/2015 - - - 2015/2016 6 1 16.7% 5 2016/2017 5 2 40% 80

DISCUSSION

These observations and analysis suggest that, for awabuki sweet viburnum at least, there is a very strong trend towards many more plants of this species appearing in conservation reserves in recent years. Most of the plants that have been observed are also relatively young, indicating that this is also a relatively new phenomenon and the rate of invasion of this species is very high. This can be explained by the fact that this species is relatively new to cultivation in SEQ, has become very popular in a short period of time, reaches

reproductive maturity relatively quickly, and is being dispersed into conservation areas by birds and other animals that eat its fruit. 129

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The results for golden trumpet tree and giant bird-of-paradise are not as conclusive. Due to the fact that there have been relatively few populations of golden trumpet tree recorded, a longer period of time may be required to determine how invasive this species actually is. At the very least its rate of invasion seems to be less rapid than that of awabuki sweet viburnum. This may be due to the smaller number of plants being cultivated in SEQ, the fact that plants take a longer time to reach reproductive maturity, and/or the fact that this species is primarily wind-dispersed rather than animal-dispersed.

The situation with giant bird-of-paradise is much more unusual. The fact that it has been in cultivation for so long and has only recently begun to invade conservation areas is strange, and may be due to birds or other animals only recently starting to utilise its seeds. The survey data analysed here also clearly shows that coastal areas of SEQ seem to be at greatest threat of invasion by this species.

REFERENCES

Atlas of Living Australia Website. http://www.ala.org.au. Accessed 14 September 2017.

Navie, S.C. (2013a). Golden Trumpet Tree (Tabebuia chrysotricha). Weed Watch – September 2013. (Technigro, Gold Coast).

Navie, S.C. (2013b). Awabuki Sweet Viburnum (Viburnum odoratissimum var. awabuki). Weed Watch – April 2013. (Technigro, Gold Coast).

Navie, S.C. (2014). Giant Bird-of-Paradise (Strelitzia nicolai). Weed Watch – September 2014. (Technigro, Gold Coast).

APPENDICES

Appendix 1. Sightings of emerging woody weeds during recent surveys in SEQ. Conservation area Date surveyed Estimated number of plants sighted Handroanthus Viburnum Strelitzia chrysotrichus odoratissimum nicolai Brisbane Koala Bushlands February 2011 0 0 0 Mount Coot-tha Forest March 2011 0 0 0 Kholo Bushland Reserve March 2011 0 0 0 Keperra Bushland March 2011 0 0 0 Brightview Street Reserve April 2011 0 0 0 Wolston Creek Bushland Reserve April 2011 0 0 0 Tingalpa Creek Reserve May 2011 0 0 0 Wacol Bushlands May 2011 0 0 0 Pooh Corner June 2011 0 0 0

Mount Coot-tha Forest June 2011 3 0 0 130

Banks Street Reserve June 2011 0 0 0 Page

Conservation area Date surveyed Estimated number of plants sighted Mount Coot-tha Forest October 2011 0 0 0 Handroanthus Viburnum Strelitzia chrysotrichus odoratissimum nicolai Mount Coot-tha Forest November 2011 0 0 0 Toohey Forest January 2012 0 0 0 Wyaralong Dam April 2012 0 0 0 Wally Tate Park June 2012 0 4 0 Sgt. Dan Stiller Memorial Reserve July 2012 0 0 0 Brisbane Koala Bushlands April 2013 100 0 0 Whites Hill Reserve June 2013 0 0 0 Hervey Bay Fraser Lions Park July 2013 0 0 2 Robinson Park October 2013 0 5 0 Porter’s Paddock Reserve January 2014 0 0 0 Boondall Wetlands March 2014 0 0 0 Brisbane Koala Bushlands April 2014 0 0 0 Coomera Waters Reserve June 2014 0 8 20 Bains Road Reserve June 2014 0 0 0 Galapagos Park June 2014 0 2 0 Mt. Coolum National Park July 2015 0 0 5 Noosa NP (Mt. Emu Section) July 2015 0 0 0 Wally Tate Park August 2015 0 7 0 Deagon Wetlands January 2016 0 3 0 Boondall Wetlands February 2016 0 2 0 Raven Street Reserve March 2016 0 3 0 Toohey Forest October 2016 20 1 0 Pine Ridge Conservation Park October 2016 0 0 30 Dowse Lagoon January 2017 0 3 0 Porter’s Paddock Reserve January 2017 0 5 0 Nerang State Forest/NP June 2017 100 0 50

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SURVIVAL AND BUOYANCY OF HYGROPHILA COSTATA STEM FRAGMENTS IN SALT, BRACKISH AND FRESH WATER.

Setter, M.J.1, Setter, S.D. 1 and Styman, D.T.2

1 Biosecurity Queensland, Department of Agriculture and Fisheries, Centre for Wet Tropics Agriculture, South Johnstone, Queensland, 2 University of Queensland

ABSTRACT (SUMMARY)

Hygrophila costata is a perennial semi-aquatic plant listed as Category 3 Restricted Matter under the Biosecurity Act 2014, Queensland. It has been found growing in many creeks and rivers in Far North Queensland, where it is displacing native vegetation and colonizing/stabilizing otherwise transient sand banks. The impacts of H. costata are not yet fully understood but effects on hydrology and species composition are believed to be detrimental. This paper summarizes two experiments investigating components of the weed’s dispersal ecology. In the first experiment, H. costata stem fragments were placed in salt, brackish, and fresh water for varying time periods over 21 days, then removed and planted in a suitable medium to observe survival and establishment. The fragments in the fresh and brackish water remained viable for 21 days and established readily when planted. The fragments in saltwater were viable for 14 days but dead by day 21. A second study examining buoyancy of stem fragments with and without leaves concluded that fragments in freshwater remained floating for 21 days in either case. In brackish water, they floated for 21 days with leaves and 12 without. In saltwater, fragments floated for seven days with leaves and three without. Within the experimental period, free-floating fragments in fresh and brackish water produced new leaves and roots from the nodes. These findings have implications for the spread and establishment of H. costata in instances where vegetative fragments become waterborne for extended time periods (e.g. flooding or storm events). The information may be useful in approximating dispersal patterns and distribution of the weed, especially when combined with existing modelling studies, and may influence choice or timing of control techniques. Keywords: hydrochory, dispersal, aquatic weeds

INTRODUCTION:

132 Hygrophila costata (Acanthaceae) is a perennial semi-aquatic plant native to Central America, and has been recorded as an aggressive environmental weed in several Page

countries, including Australia (Csurhes 2008). First recorded in Australia in 1995, several populations of the plant have since been observed in wetland and freshwater systems in New South Wales and South East Queensland (Csurhes 2008; Cuthbert 2013). Hygrophila costata has become naturalised in several of these locations, where the populations are dense but relatively localised. Hygrophila costata appears to spread primarily through vegetative reproduction, and can establish new plants and populations from small fragments of stem (Moran & Moscato 2008; NSW Department of Primary Industries 2014). Although isolated populations were likely introduced as ornamentals in the aquarium market (Csurhes 2008; Petroeschevsky & Champion 2008), there has been concern that H. costata may be able to travel and spread to previously unaffected waterways via flood waters, and possibly ocean currents if vegetative fragments could tolerate salt water. There is particular concern that mechanical control may result in small free-floating stem fragments, and this work aims to quantify its ability to disperse. There is a lack of ecological information about the species, and identifying and addressing these knowledge gaps will help develop and maintain effective management systems. Due to the importance of aquatic ecosystems in Australia, action should be taken to contain and manage all current infestations (Weber and Panetta 2006). This paper describes two experiments: an assessment of salinity tolerance and an assessment of buoyancy time. Both of these play key roles in understanding the dispersal of H. costata in the Wet Tropics.

MATERIALS AND METHODS The two experiments were conducted at the Centre for Wet Tropics Agriculture at South Johnstone in north Queensland. In a laboratory, twelve fish tanks were randomly allocated one of 3 water types - salt, fresh, and brackish (50/50), giving four replications for each treatment. Temperature, pH, and salinity of the water in each tank were monitored weekly to ensure conditions remained relatively constant throughout the duration of the experiments. Stem material of H. costata for the experiments was collected manually (Figure 1) from an infestation on the Russell River (17° 17’ 53. 84 S, 145° 57’ 13. 42 E) on 16/08/2016, and transported immediately to the laboratory.

Experiment 1 - Stem Survival All foliage was removed from stem material and the stems cut into 1680 small sections, each containing a single node. One hundred and forty of these stem sections were then randomly selected and placed into each tank. At designated retrieval intervals (0 ,3 ,6, 9 and 12 hours, and 1,2,3,4,5,6,7,14 and 21 days), ten stems from each tank were randomly selected, removed, and the following parameters recorded: basal diameter, fragment length, whether buoyant or not upon removal, and height of any new growth. Removed stem fragments were planted in small plastic containers filled with standard potting mix

and with holes inserted to allow drainage. The containers were then grouped together in larger tubs and placed in a shadehouse where they were watered on a twelve hourly basis 133 using an overhead irrigation system. Each week, the height and number of new shoots on each fragment was measured and recorded for four weeks. Any stems exhibiting no new Page

growth at the end of the four-week period were recorded as not surviving. The mean maximum and minimum temperatures experienced at the site throughout the combined seven week period were 27.1°C and 17°C, respectively (Bureau of Meteorology, 2016).

Experiment 2 - Stem Buoyancy Two hundred and forty stem sections containing a single node were obtained from the original plant material and then randomly split into two lots of 120. One lot had all leaves removed while the other was left intact. Ten fragments of each lot (leaves and no-leaves) were added to each tank. Tanks were then monitored daily (at 24 hour intervals) for 21 days. Any fragments observed to have sunk were removed, measured (basal diameter, fragment length, leaf length and width), and discarded. At the end of the 21 day period, any floating fragments were recorded as remaining buoyant for more than 21 days.

Figure 1. Stephen Setter (DAF) and Dylan Styman (UQ) collecting H. costata material from the Russell River.

RESULTS: Experiment 1 - Stem Survival The stem fragments in the fresh and brackish water remained viable for 21 days and established readily when planted (Figure 2). In contrast, viability of fragments in saltwater declined over time with only 27.5% alive after 14 days and all dead by day 21.

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Figure 2: H. costata stem fragment survival in varying water types.

Experiment 2 - Stem Buoyancy All stem fragments with leaves attached remained floating for 21 days in freshwater, compared with 10% if leaves were removed (Figure 3). In brackish water, 10% of fragments were still floating after 21 days, but if leaves were removed all fragments lost buoyancy after 12 days. In saltwater, fragments floated for a maximum of only seven days with leaves and three without.

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Figure 3: H. costata buoyancy with and without leaves Page

DISCUSSION: The experiments in this study used small fragments containing only one node, which would be the minimum required to start a new infestation. It is probable that larger fragments may have different survival and buoyancy abilities. Nevertheless, the findings are that stem fragments could stay afloat and alive for over 21 days in fresh water, enabling dispersal downstream, between waterbodies in flood events, and even upstream via tidal push. The 21-day period should be ample time for H. costata fragments to reach the mouth of many creek/river systems. Whilst both survival and buoyancy of stem fragments was affected by salt water, a proportion were still floating and viable after seven days. A plausible time frame for the deposition of debris by Wet Tropics coastal currents is likely well within 90 days (Mason & Hardy 2008), by which time, all fragments would have lost buoyancy and perished in the high salinity. However, also according to modelling by Mason & Hardy (2008), 90% of propagules (in this case stem fragments) would beach within 20 days of release from a river mouth, so it would be expected that a substantial proportion of H. costata fragments could beach within the 7 day time frame. So although the risk of spreading inter-river via salt water routes is low, the risk of spreading between creeks and fresh waterways remains high. Although floods are responsible for the breakup and distribution of fragments within aquatic systems, well-intentioned control operations may in fact contribute to further spread of the weed. This reinforces the idea that anthropocentric mechanisms can be the primary mechanisms for the spread of aquatic weeds in Australian waterways (Petroeschevsky & Champion 2008). The presence of leaves on stem fragments helped them retain their buoyancy in all water types, so any control treatment that removes leaves will help it sink and reduce the risk of long distance dispersal.

ACKNOWLEDGMENTS We thank Michael Graham (DAF), and Cairns Regional Council Staff for assistance with locating and harvesting H. costata specimens, as well as Shane Campbell and Joe Scanlan for commenting on the draft manuscript.

REFERENCES

Bureau of Meteorology (2016). ww.bom.gov.au/climate/averages/tables/cw_032037.shtml. Accessed November 8th 2016.

Csurhes, S. (2008). “Pest Plant Risk Assessment: Glush Weed Hygrophila costata”. Biosecurity Queensland, Department of Primary Industries and Fisheries. Queensland Government.

Cuthbert, K. (2013). “Border Security: Spotlight on Weeds”. Plant Protection Quarterly. Volume 28, Issue 3, Pages 66-67. 136

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Moran, P., Moscato, V. (2008). “Hygrophila costata demonstration and pilot eradication project”. IN: Proceedings of the 16th Australian Weeds Conference, Cairns Convention Centre, Queensland, Australia. 18-20 May, 2008. Pages 437-440. Queensland Weed Society.

NSW Department of Primary Industries (2014). “Hygrophila (Hygrophila costata)”. NSW Government. Accessed 7th November 2016. weeds.dpinsw.gov.au/Weeds/Details/73

Petroeschevsky, A., Champion, P. (2008). “Preventing Further Introduction and Spread of Aquatic Weeds through the Ornamental Plant Trade”. IN: Proceedings of the 16th Australian Weeds Conference, Cairns Convention Centre, Queensland, Australia. 18-20 May, 2008. Pages 200-302. Queensland Weed Society

Weber, J., Panetta, F. (2006). “Weed Risk Assessment of the DEH Alert List and Other Non-native Plant Species”. IN: Proceedings of the 15th Australian Weeds Conference, Adelaide, South Australia, 2006. Pages 24-28.

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IMPLEMENTING PEST PLANNING ON THE GROUND: KEEPING THE PIGS OUT OF THE CHOCOLATE PUDDING.

Geoff Lundie-Jenkins and John Hodgon Department of National Parks, Sport and Racing, Queensland National Parks and Wildlife, Lvl 13 400 George Street, Brisbane, Queensland 4001.

ABSTRACT

The Queensland Parks and Wildlife Service (QPWS) has developed a planning framework aligned with international conservation planning standards and agency objectives to provide clear guidance to operational staff for fire, pest, visitor, Indigenous cultural and historical cultural on-ground management operations. The framework identifies key values, has management instruments that articulate strategic management directions and objectives to mitigate impacts to key values and provides adaptive management processes that operational staff can use to improve operational activities. As an extension of the planning framework the QPWS web-based pest management system provides a user friendly system that meets agency business requirements and objectives. As a result the agency now has a system that provides a direct link between a park’s key values and operational pest management activities. The system provides the how, when, where and why pest impacts on a park’s key values are managed operationally, multi-scale reporting abilities and electronic endorsement and approval functions not previously available within the agency.

INTRODUCTION

The Queensland Government is committed to and prioritises controlling pest plants and animals on the over 13 million hectares of national parks, state forests and other lands under its control. Impacts from invasive pest species are one of the biggest threats to biodiversity and they can dramatically alter habitats, ecosystems and ecological processes and drive threatened species to extinction. QPWS takes seriously its obligations under the Nature Conservation Act 1992, Forestry Act 1959 and Biosecurity Act 2014 to undertake pest management activities on the State’s park and forest estates to conserve the natural values of these areas.

Values based management framework

QPWS has developed the Values Based Management Framework (VBMF) to enable it to manage the States’ park and forest estates in a way that is underpinned by a robust, evidence-based decision making framework. The framework when fully operational will drive resource allocation decisions, across the full range of service delivery areas, allowing the agency to best use the resources available and determine what resources are required to manage parks to a standard expected by the people of Queensland. Crucially, the 138 framework will provide QPWS with an evidence base to support future funding requests, alternative revenue strategies and/or reprioritisation of existing investment.

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Under the VBMF, strategic priorities for management of the parks and forests estate are based on a values-focused methodology. Values assessments are a fundamental component to implementing the VBMF and provide the foundation or point of truth for park management by defining what the park’s key values are, what the threats are to these values, and what QPWS need to do to manage these values effectively. This information is used to develop management plans or statements as well as the detailed thematic strategies which define the Strategic Management Directions (SMDs) and objectives across the key management elements (including Fire and Pest Management) in order to better align the desired management effort with priorities for protecting and enhancing key values. These elements of the VBMF are reflected in Figure 1. The framework is fundamentally about keeping our park values healthy by: • making sure we manage and protect the things that matter most; • focussing our management effort on priorities; • having decision support tools to guide our day-to-day management; • building support for what we do; and • learning by doing.

Under the framework park management is treated as a living process, where there is a cycle of planning, prioritising, doing, monitoring, evaluating, and reporting then adapting our management, if required, and improving over time.

Figure 9. Elements of the Values Based Park Management Framework.

Levels of service

The framework also introduces Levels of Service (LoS) as a key component of park planning designed to guide prioritisation and management of all QPWS protected areas 139 based on their values, threats and complexity of management. A safe, minimum ‘acceptable standard’ for park management has been established for all parks and forests Page

in Queensland. Based on a park’s values, risks and stakeholder interactions the LoS can be raised if required – effectively establishing a specific set of desired management standards for each park.

There are five LoS, ranging from acceptable up to exceptional for the nine elements of park management. It is important to remember that an acceptable LoS is still good management. What is right for each park varies according to circumstances such as the significance of its values, the types and level of threats to those values and the complexity of management issues.

For each of the nine management elements there is both a current LoS and a desired LoS. The desired LoS for pest management has been set for all protected areas in the state and describes the optimum level of knowledge, consultation and priority for pest management on each protected area. Both LoS are included in a pest strategy along with SMDs to improve, maintain or moderate the level of knowledge, consultation and priority for pest management on a protected area.

QPWS pest management system

The new QPWS Pest Management System went ‘live’ on 10th April 2017. The system has been built on the Lands-Tracker web based platform used to deliver QPWS’s online FLAME Fire Management System. It has been developed in conjunction with the VBMF and integrates the new language and focus on key values introduced with that framework.

This approach ensures there is a clear and direct link between a protected area's key values and on-ground pest management operations. The new system provides the platform for all operational pest management processes including pest strategies, pest plans, on-ground treatments and pest reporting. All pest strategies, plans and treatments and mapping of pest infestations and management activities previously implemented through paper-based system and ParkInfo are now performed within the new spatially enabled online system.

Delivery of the new pest system both integrates with the new VBMF and aligns with international conservation planning and pest management standards. It adopts the international nomenclature of "prevention, eradication, containment and impact reduction (asset protection)" (Clarkson and Grice 2013) to clearly define strategic objectives for pest management. These directions are represented in spatially delineated pest management zones which provide the basis for monitoring and reporting on the effectiveness of pest management.

The new system incorporates significant enhancements to workflow approvals and reporting capability including the establishment of a real-time executive dashboard. The system is user friendly and meets QPWS business requirements and objectives, and improves the agencies abilities to report and conduct analyses on the effectiveness of pest management operations.

Keeping the pigs out of the chocolate pudding

As the pest system has been developed as an extension of the VBMF it ensures there is a clear link between a park’s key values and implementation of operational pest 140 management activities on the ground. The values assessments undertaken as part of the planning framework serve to identify the key values and articulate how, when, where and Page

why pest impacts are threatening these values. Using the hypothetical example key value of a “Chocolate Pudding” the system provides managers with a tool to define and map information on the location and extent of the ”Pudding”, identify and map pests which are impacting the “Pudding”, detail spatially and temporally specific management directions and objectives to “protect” or “reduce impacts” from these pests on the “Pudding” and record important information in relation to both the implementation and effectiveness of actions initiated to contribute to the achievement of the objectives. This continuum from values to on ground treatments is illustrated in Figure 2 and provides the basis for ensuring our pest management is directed to best effect to prevent the pigs eating all the “Chocolate Pudding”.

KEY ACHIEVEMENTS AND OUTCOMES

Key achievements and outcomes from implementation of the new pest management system include: • Integration with the new VBMF to ensure pest management activities are focussed on the protection of key values, • Integration of data on pest infestations derived from QPWS legacy systems, Biosecurity Queensland and other jurisdictions to ensure that QPWS pest management is implemented in a broader context and in a manner that complements programs by other land managers, • Increased efficiency and clear audit trails in management and approval of business processes for pest management, • Significant improvements in data capture, cleaning and quality through standardized online data capture, storage and checking protocols, • Increased senior stakeholder reporting visibility through online real-time executive dashboards and customized reports, • Replacement and decommissioning of existing legacy systems (ParkInfo), • Time savings for the QPWS spatial team as data roll-ups not required as spatially enabled platform captures spatial data to corporate servers, • More efficient and effective management of ownership, origin and currency of spatial pest management datasets, • Important historical data is accessible through the online system whilst less critical data has been archived, • Regional siloed data has been collected, cleansed and incorporated into corporate datasets improving on-going data governance and quality. • Significantly enhanced capacity to monitor and report against pest management programs. • Delivery of a state-wide training program and establishment of a support framework that includes system champions, service desk and the Pest Team to help users adapt to the new platform. • A comprehensive set of online system how to guides.

The new Pest System delivers an integrated pest planning and reporting tool that will enable a much more sophisticated oversite of all aspects of our pest management than 141 was previously available. Delivery of this new platform for pest management is a great milestone for QPWS and will greatly enhanced QPWS’s credibility as a land management

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ACKNOWLEDGMENTS

Development of the pest management system has been supported by significant input from both the QPWS executive and operational staff across the state to ensure the system was fit for purpose. Development of the system was directed by a Project Board including a representative of the Executive Leadership Team. The scoping of system requirements and capability as well as prototype and user acceptance testing were directed by a User Reference Group of operational staff from the operational regions within QPWS. The input of all these people is readily acknowledged and has been important in successful implementation of the system.

REFERENCES Clarkson, J.R. and Grice, A.C. (2013). Managing plant invasions: Strategic options defined. Proceedings of the 12th Queensland Weed Symposium. The Weed Society of Queensland, Brisbane. pp. 35-38.

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Figure 10 An overview of the Pest Management System Page

GOOD NEIGHBOUR PROGRAM (GNP) – MANAGING PESTS IN THE FLINDERS SHIRE

Robyn Young Flinders Shire Council 34 Gray Street, HUGHENDEN QLD 4821

ABSTRACT

When one neighbour is seemingly doing nothing about their noxious weed infestations and another is working tirelessly to control and eradicate, conflict can often erupt. Flinders Shire Council addressed this with the Good Neighbour Program (GNP).

The concept of the GNP was tested with a case study to investigate if a boundary protection zone approach would work on a broad scale and its feasibility of establishing such buffers. The case study demonstrated that the establishment of property protection zones for pest management is relatively quick, easy and of low to moderate cost. Establishing the minimum buffer zone is both achievable and feasible.

With the positive results of the case study council moved forward to implement the GNP, applying for Queensland Government Drought Funding. The program has been implemented deliberately and methodically, to achieve positive outcomes. Appropriately trained staff attended all participating properties to help complete a basic property and boundary weed management plans. This also opened the path of communication and allowed for some invaluable extension activities. Participants were allocated herbicide of which they were responsible for its application.

Keywords: Good Neighbour Program, GNP, Buffer Zones, Pests

INTRODUCTION

The management of pests is a shared responsibility of land managers, industry, the community and all levels of government. When one neighbour is seemingly doing nothing about their pest infestations and another is working tirelessly to control and eradicate, conflict can often erupt. Flinders Shire Council addressed this with the Good Neighbour Program (GNP).

The case study

The case study was conducted by the Queensland Governments War on Wester Weeds 143 Project (WOWW), Southern Gulf Natural Resource Management (SGNRM) and Flinders Shire Council. The principal aim of the case study was to assess the feasibility of Page

establishing weed-free property boundary protection zones for a group of adjoining properties and use this information to further develop the GNP in the Flinders Shire.

The case study demonstrated that the establishment of property boundary protection zones for weed management is relatively quick, easy and of low to moderate cost. The minimum 10m zone for fence line zones is feasible. The establishment of 250m watercourse zones required greater resources, but all landholders considered this to be feasible to establish and maintain. The boundary protection zone approach was fully supported by landholder participating in the case study. The GNP will not only assist individual properties, but will also complement the objectives of the Flinders Shire Local Government Biosecurity Plan and regional aspirations for weed management. Implementing GNP The positive results of the case study initiated the implementation of the GNP in the Flinders Shire. Council determined that the best way to roll out the program, was by seeking funding to support the implementation of the key elements. Council applied for Queensland Government Drought funding in conjunction with Dessert Channels Queensland (DCQ) and McKinley Shire Council and were successful in its application. The approved funding was for the purchase of herbicide and assist with mapping.

Participating land holders had to sign a participation agreement that gave them ownership of containing the spread of pests from property to property. The key elements of the participation agreement are as follows: • Landholders agree to maintain a declared weed free buffer zones that is a minimum of 10m from boundaries, 10m either side of the bands for 250m upstream within defined watercourses from a boundary, and 10m either side of gazetted roads, public access roads and powerlines. These buffer zones are to be reviewed annually. • All stock routes are to be kept free of declared weeds. • Landholders agree to provide a weed hygiene declaration for all stock leaving a property and request one for stock entering a property, and use best-practice measures to minimise the spread of weed seeds by livestock. • Landholders agree to participate in wild dog control programs, catchment group projects and funding applications. • Landholders agree to complete a property boundary management plant and commit to achieving its objectives.

Project governance To provide governance to the project and allocate the valuable resource, council developed a herbicide requirement estimation tool (March & Cullen 2015) (March et al. 2004). Rural Lands staff attended all participating properties to assist with the establishment of basic property maps and, using the estimation tool, allocated herbicide. Scrubmaster (200 g/kg Tebuthiuron) was supplied to treat boundaries with little native trees and Access™ (240 g/L Triclopyr & 120 g/L Picloram) was supplied to treat sensitive areas on 144 watercourses and near native trees.

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All participants were issued with a GNP Packs that included a pellet dispenser, Vigilant™ II (4.47 g/L aminopyralid), SGNRM Weed ID book, and an herbicide application declaration. When participants collected their GNP Pack, Rural Lands staff seized the opportunity to do some one on one training explaining how many pellets were required per size of tree, the process of basal barking for best results, how to use the dispenser properly and how to use Vigilant™ II. Participants have returned forms confirming herbicide application.

Positive outcomes of the GNP To date 70 properties in the Flinders Shire are participating in the GNP that is 34% participation of the entire shire. All participating properties have been mapped with accompanying photos of monitoring points. 3629.5 km of Boundary, 330.9 km of watercourse and 1090 km of Access roads have established buffer zones.

Having staff attend all of the sites, has allowed for invaluable extension activities. Information gaps have been identified and information has been supplied to minimise this.

Owners of clean properties are advising of their delight that neighbouring properties are participating as they can rest easy knowing that cattle cannot lean over the fence and fill up with the seed and infest their clean paddocks.

Several other shires have been in contact as they are expressing interest in starting a GNP in their shire, which is heartening for us, as shires we need to be ‘Good Neighbours’ too.

CONCLUSION

Participation in the GNP has far exceeded expectations. Council has received many letters of appreciation from participants. Participation in the program helped to close the gaps in information, including the identification of weeds and herbicide application. It gave a starting point to those who felt the problem was too big to tackle, and gives future direction. Boundaries that have both neighbours participating ensures that those that are free or well controlled will not be negatively impacted by their neighbours infestation. The actual distribution of herbicide physically demonstrated to producers that a small amount of herbicide and strategic application can have great results for relatively low costs.

ACKNOWLEDGEMENTS

We would like to acknowledge the Queensland State Governments Drought Funding for supporting the implementation of the GNP key elements. We would also like to acknowledge the case study working group for their continued support to Flinders Shire Council to implement the program.

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REFERENCES Page

March N and Cullen S (2015) Flinders Shire Good Neighbour Program Case Study. (Department of Agriculture and Fisheries – Queensland Biosecurity)

March N, Spies P, Spies W (2004) Prickly Acacia National Case Study manual – Approaches to the Management of Prickly Acacia (Acacia nilotica Subsp. Indica) in Australia (Department of Natural Resources, Mines and Energy, Australia)

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SUCCESSFUL COMMUNITY ENGAGEMENT FOR WEED CONTROL ON PRIVATE LAND. CONSERVATION PARTNERSHIPS – CITY OF GOLD COAST

Lexie Webster, Todd Burrows and Donald Mackenzie City of Gold Coast

ABSTRACT The Gold Coast is one of Australia’s most biodiverse cities, with the majority of its vegetation located on private land. One of the main threats to the city’s biodiversity is environmental weeds and in acknowledgement of the crucial role private landholders play in the management of the city’s vegetation, the City of Gold Coast’s (City) Conservation Partnerships (CP) team delivers a range of voluntary schemes to private landholders with bushland on their properties. The schemes, which include Land for Wildlife (LfW), Voluntary Conservation Agreements and a grants program, engage and support landholders and build their capacity to control weeds and restore their properties’ native habitat. • The CP team has created an engaged, active membership through the provision of meaningful support that is: • in line with best practice management, to ensure long-term success and best resource efficiency; • tailored and relevant to the landholder’s level of knowledge, skills and capacity e.g. tailored property management plans and onsite visits to identify plants and demonstrate weed control techniques; • diverse in its content and delivery style, to engage people with varying interests and learning styles e.g. property visits, management plans, workshops and field trips; and • ongoing and regular, so landholders’ knowledge and capacity can evolve over time and motivation is maintained. Since LfW’s inception on the Gold Coast in 1998, the CP team has continued to enhance and evolve its programs to meet the community’s needs and deliver high quality habitat management outcomes. What started as a team of one offering broad advice, a sign for the gate and a hundred plants has now grown and is supported by community, peers and political leaders alike for its meaningful and well managed delivery of on-ground outcomes and contribution to the city’s conservation network.

INTRODUCTION The City recognises private landholders as a major partner in, and contributor to, the management and protection of the city’s natural areas. In acknowledgement of this the City’s CP team delivers a range of cost-effective voluntary schemes, through its 147 Conservation Partnerships Program (CPP), to support landholders’ efforts in achieving on- ground environmental change, much of which involves weed control. Page

The team started with one officer in 1998 delivering LfW and has since grown to four officers delivering four schemes. The team prides itself on the high level of service it offers, quality of advice it delivers and calibre of resources it provides to members. Most importantly, the team provides all of this on an ongoing basis, allowing landholders to grow and learn to their full potential with as little or as much time as they need.

OBJECTIVES The City recognises that supporting private landholders is a cost effective approach to improving habitat management practices on a landscape scale. However, for landholders to change their habitat management practices, they must have the necessary knowledge, skills, resources, support and confidence. The CPP aims to: • engage and build long term partnerships with landholders with ecologically valuable properties; • increase landholders’ appreciation of their properties’ native habitat and wildlife, and the contribution it makes to the city on a landscape scale; • impart knowledge and awareness, aligned with landholders’ needs and capacity, to facilitate a greater understanding of habitat function and management practices; • provide landholders with the skills and tools required to manage their properties’ ecological values, and achieve the most effective results, efficiently and with finite resources; • motivate landholders, through awareness and education, and facilitate behavioural change to restore, protect and monitor their property’s habitat, its wildlife and the outcomes of their management activities; and • celebrate landholders’ achievements and recognise the critical individual contributions they make to managing the city’s natural areas. Following nearly 20 years of community engagement and connection, the team is confident that for the program to achieve meaningful behavioural change and on-ground outcomes, quality is better than quantity. Therefore, the team aims to maintain sustainable levels of membership rather than continually growing it, to ensure it can carry-on providing targeted high-level support to its membership.

METHODOLOGY The team achieves its objectives by delivering a tailored range of voluntary schemes to landholders. The schemes available to landholders vary in their commitment and the level of support they provide. 1. Bushland Health Checks are for landholders who either don’t have a property large enough to join an ongoing scheme, or are looking for one-off advice, rather than ongoing program membership.

148 2. Land for Wildlife is the program’s signature scheme, designed for landholders with at least one hectare of either intact habitat or disturbed area they’d like to restore. Page

It’s non-legally binding and provides unlimited, ongoing access to officers through various medium. LfW members are provided with: • on-site visits, during which officers identify both native and weed plants, point out their property’s ecological values and threats, provide advice and demonstrations on controlling weeds, restoring native habitat and how to prioritise actions in accordance with the landholders’ priorities and capacity; • property plans, tailored to the property and landholder; • resources including property maps, toolkits (leather tool-pouch, hand-saw, secateurs, knife, herbicide, surfactant and gloves), plants and books; and • free attendance to LfW workshops (topics include ecological restoration, weed identification, native plant identification and property field trips). In South East Queensland (SEQ) LfW is regionally coordinated by Healthy Land and Water across the 11 local councils delivering the scheme. Their coordination is pivotal to the success of LfW, and has provided a strong foundation for the expansion of private land conservation through local government in SEQ. Benefits have included the sharing of knowledge and pooling of resources, to deliver a regional online membership database, officer training workshops, regional website and Facebook page, and a much-valued quarterly newsletter. 3. Voluntary Conservation Agreements are legally binding agreements for landholders seeking long-term or permanent protection of their property’s conservation values. In addition to LfW benefits, landholders receive financial assistance for ecological management activities and rates reimbursement.

4. The Nature Conservation Assistance Program provides financial assistance to private landholders through a grant system. All applicants receive an onsite visit from a Conservation Partnerships officer to discuss their proposed project. Successful applicants are required to provide 30% co-contribution and receive ongoing support throughout the year. The CPP’s success can be largely attributed to the team that delivers it. The team’s officers: • possess a diverse array of technical knowledge and skills; • are highly effective communicators capable of relating to, and connecting with, a wide audience to convey complex theories; • offer a ‘tough-love’ approach to ensure landholders are achieving the outcomes they want in the most effective and efficient manner and in accordance with best practice restoration techniques; • are enthusiastic, passionate and motivated to see program members achieve great outcomes; and • are always willing and available to assist landholders with their inquiries.

“All the staff have been friendly and helpful, irrespective of how many times we ask about

particular plants. Never feel they are rushing us, as they will take as much time as 149 necessary to advise. If they say they will find out about a particular issue they always come back with information. Great Team” – LfW member Page

OUTCOMES Since its inception in 1998, the CP team has built a strong reputation in the city, based on the service it delivers, the on-ground outcomes it has achieved and the feedback landholders have provided. The greatest of the program’s achievements is its evolution from a traditional private land conservation initiative to one that delivers extensive support, relevant resources, teaches best practice techniques and achieves real on-ground outcomes through behavioural change. This evolution has been a strong focus over the last eight years since it became clear the LfW membership wasn’t equipped with the level of information required to understand ecological processes and therefore why they should carry out particular restoration methodologies recommended by the team. This lack of knowledge was a product of the low resource level originally allocated to the program and therefore, the level of engagement members had experienced and their subsequent perception of what LfW sort to achieve. This triggered a whole new approach to how the team delivered its information and incentives, and what incentives it offered. Where the team had previously only offered plants to LfW members (which often weren’t required due to a higher priority need for weed control), the team started providing restoration kits, with tools and herbicide, and the recently released SEQ Ecological Restoration Framework. Landholders only gained access to these (and plants) after attending a full day workshop on understanding ecological restoration. At the same time, officers began providing onsite weed-control demonstrations in workshops and on members’ properties. The property plans provided to landholders became more detailed to ensure they had all the information necessary and referred members to the technical notes they received. “The best experience has been attending this year's Restoration workshops and receiving the weed control work kit. I really appreciate the effort of organising such a hands-on event, with take-home benefits, and the networking opportunities that arose from it” – LfW member The feedback from the ecological restoration workshops has been overwhelmingly positive and the on-ground change in behaviour witnessed as a result has confirmed the team’s approach as the correct one. The landholders ultimately reap the rewards and are grateful for the strong advice the team gave. “Program staff are doing a wonderful job of inspiring and directing the owners' efforts to improve their properties, and I hope Council keeps on funding this grassroots work.” – LfW member Respondents to a SEQ regional survey conducted on LfW members also showed that members felt they had benefited socially from meeting and engaging with staff and other members, and that it had provided them with a sense of belonging. They also felt they were more active on their property and that the additional activity had led to an increase in their fitness. The City’s LfW scheme has established a membership of 420 members with approximately 4000 ha of retained habitat in the program and an additional 670 ha of area landholders want to restore. The team aims to attract 250 members to its annual calendar of 10 workshops, undertake approximately 200 revisits across its four schemes and sign up approximately 30 new LfW members annually.

Further to working towards these quantitative targets, which demonstrate how the team is 150 meeting its objective to engage with, up skill and resource members, results from a survey of the city’s LfW members conducted in 2015-16 show the impact the program is having Page

on members’ knowledge, skill level and behaviour. Overall member satisfaction with the program in the most recent survey was 95%. The survey showed that survey respondents’ knowledge and skills significantly improved since joining LfW (see Figure 1). It also showed that most members have changed their behaviours to improve their management practices and in turn their property’s habitat (see Figure 2).

Figure 1. Change in members’ knowledge and skills since joining LfW.

Changes in weed control as a result of joining LfW

Strongly agree Agree Neutral Disagree Strongly disagree

50 0 0 0 13 16 11

45 34 37 42

50 53 53 42

My weed knowledge My skills in managing I have changed my The condition of my has increased weeds has improved weed management property is better

practices 151 Figure 2. Change in weed control as a result of joining.

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Anonymous testimonials collected in surveys provide anecdotal evidence that the program has significantly assisted members with the management of their property, provided relevant resources and created social opportunities to connect with like-minded peers. “The best part of being in the program is connecting with the Land for Wildlife officers, whether through the workshops, a walk around the property, talking over a concern about weed control or pest control, and generally sharing information about conservation on the property.” – LfW member The program has provided the opportunity to develop new partnerships with a wide audience including landholders, NRM bodies, knowledge experts and State and Local government. These partnerships will continue to evolve to maximise the program’s potential output. The benefits experienced by members and the City from these partnerships include the leveraging of co-funding for projects with federally significant ecological values, opportunity for funded work on member properties, improvements and cost-efficiencies in program delivery, and knowledge gain. The program has also been successful in changing behaviour within the organisation. Private land partnership and community environmental engagement concepts are now embedded in the Corporate Plan and the City’s Our Natural City Strategy. The CPP, through its successes, has become recognised as a key program for the City to deliver a range of its nature conservation, pest management and catchment activities. FUTURE PROSPECTS The team is committed to being leaders in private land conservation initiatives and will continue to remain agile and innovative as members and their needs change and new technologies and engagement practices emerge. This will include a broadening of communication approaches and materials to support differing landholders’ needs. The development of online resources, such as short instructional videos demonstrating current restoration and weed control techniques, will be a resource effective mechanism to keep members’ skills up-to-date and will appeal to many landholders who are time poor. The CP team is also keen, via these on-line platforms, to share their lessons and success stories with other internal and external groups working with volunteers and/or landholders. Whilst engaging with community to effect change has its challenges, the rewards reaped from their success stories are inspiring and supports long-lasting environmental outcomes. “What was really astounding was the passion that staff emanated. It was as though they were as keen about each of our own individual properties as we ourselves, determined to equip us with the knowledge and support for our patches to be restored and maintained and become as ecologically sound as they can possibly be. Something that is also worthy of comment is the fact that unlike most areas of our lives today where it’s an accepted fact that almost everyone ‘wants’ something from one, you freely ‘gave’ us your time and energy and all those resources and the assurance that your support is always at hand. Amazing!!!” – LfW member

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SIAM WEED DISPERSAL MECHANSIMS

Brooks1, S.J., Setter2, S.D. and Gough1, K.L. Biosecurity Queensland, Department of Agriculture and Fisheries. 1Tropical Weeds Research Centre, PO Box 187, Charters Towers, 4820. 2Centre for Wet Tropics Agriculture, PO Box 20, South Johnstone, 4859.

ABSTRACT

The primary dispersal mechanism for Chromolaena odorata (Siam weed) is generally considered to be wind dispersal, however research and field mapping suggest several additional natural and anthropocentric mechanisms are also important. Research has concentrated on the biology of the weed and natural dispersal mechanisms such as wind and water. Historical mapping records show dispersal along roadsides, and into rural and environmental areas. Spread via human vectors, including work and recreational vehicles, as well as animals probably contributed to the creation of new infestations. Prevention, early intervention and management actions should consider all dispersal mechanisms. Keywords; anemochory, hydrochory, anthropochory, epizoochory

INTRODUCTION

Chromolaena odorata (L.) R. King & H. Robinson. is a weedy species within the Asteraceae family. The seeds (achenes) have a pappus (Figure 1) that aids wind dispersal (anemochory) which is considered the primary dispersal mechanism in the literature (e.g. Carriere et al. 2002).

Figure 1. A photo of a 9 mm long C. odorata achene (seed) including pappus and the achene has fine hairs along ridges (inset).

Chromolaena odorata is an apomictic species that does not require pollination to produce 153 viable seed. A Brazilian study found the formation of embryos in 70% of seed prior to anthesis (mature stamens) (Coleman 1989). A single mature unpollinated C. odorata plant

can start an infestation. It has been estimated that a heavily infested square metre of C. Page

odorata can produce 86 000 seeds (Gautier 1993). Low growing stems can take root but other forms of natural vegetative propagation have not been confirmed. Any vegetative reproduction would be dwarfed by the quantity of seed produced. Chromolaena odorata was the target of a nationally cost-shared eradication program from 1994 to 2012. During the eradication program, trials were conducted to understand dispersal mechanisms and refine search strategies. The demise of the program has created the need for a greater range of stakeholders, across a wider area to understand and make management decisions regarding the potential sources and movement of C. odorata seed. The eradication program also had considerable spatial data that can be used to show the results of different dispersal mechanisms. Aspects of the species biology, mapped infestations, research trials and literature are summarised to highlight the variety of C. odorata seed dispersal mechanisms and suggest some mitigating actions.

METHODS AND RESULTS

Seeds used in the experiments were collected on 28/10/09 and 1/12/10 from the Pinnacles west of Townsville or 10/9/09 at Silkwood south of Innisfail. Germination studies were conducted in petri dishes under 12 hr day night incubator conditions at 30/20 °C until germination ceased. Physical tests of viability were conducted on un-germinated seed.

Wind dispersal (anemochory)

Fall rates Two seed-drop tests were conducted in a small laboratory using seed from the Pinnacles by releasing the pappus from forceps at a height of 2 m and timing the fall to the ground. The length of each seed and the maximum length and width of the pappus was recorded prior to dropping (Table 1). The first test of 40 seeds was conducted on 15/12/10, when two researchers dropped each seed once. On 2/1/12, 100 seeds from the same batch were dropped twice by one person. Mean data from each test is shown in Table 1. The minimum fall rate of Siam weed achenes (seed) was determined to be 0.36 m/sec, which is comparable to Gautier (1993) who recorded 0.37 m/sec. The mean fall rates from the second trial were influenced by the lower pappus width after seed storage. Table 1. Mean C. odorata seed dimensions and fall data from the drop tests and estimated dispersal distance from a release height of 2 metres using the minimum fall speed. Test Mean Mean Mean Mean Mean Min Distance Distance (number of pappus pappus seed weight of drop drop from 8 from 18 seeds width length length 50 seeds rate rate m/sec m/sec measured) (mm) (mm) (mm) (g) (n=4) m/sec m/sec wind (m) wind (m) 1 (40) 5.43 5.37 4.04 0.01295 0.573 0.352 45 102 2 (100) 3.11 5.21 4.01 0.01260 0.881 0.357 45 101

The fall rate, height above surrounding vegetation and wind speed can be used to

estimate dispersal distance. A basic dispersal distance for a release height 2 m above the 154 surrounding vegetation into strong and gale force winds is shown in Table 1. In the Page

absence of updrafts or elevated launch heights, the dispersal by wind is likely to be under 100 m.

Water dispersal (hydrochory) Immersion Packets of 50 C. odorata seeds from the Pinnacles and Silkwood collections were placed in replicated fish tanks containing; no water, fresh creek water, a 50/50 mix of creek and sea water (brackish) and sea water. Packets were removed at intervals up to 126 days and the seeds subjected to germination and viability testing. Silkwood seeds retained similar levels of viability when immersed in fresh, brackish and sea water for up to 126 days (Table 2). The data for the Pinnacles seed lot were similar with viable seed remaining in all water treatments after 126 days, except there was germination in the packets prior to their removal from the fresh water tanks. Overall, immersion is not a barrier to viable seed dispersal. Table 2. Percent viability of Silkwood C. odorata seed after immersion for 0 to 126 days (mean of 4 replicates).

Immersion time (days) Treatment 0 2 4 8 14 21 28 42 70 126

No water 45.5 46.3 46.5 Fresh creek water 50.5 51.0 45.8 51.0 41.0 43.5 40.0 43.5 49.0 50/50 mix sea/creek 52.5 54.3 56.3 58.5 56.1 59.5 55.0 55.5 53.8 Sea water 47.5 49.8 51.5 49.0 47.5 44.5 43.0 37.0 35.0

Buoyancy Seeds from both collections were used in two trials with two replicates. In the first trial 50 seeds were placed in 500-ml beakers of fresh water and floating seeds recorded every 15 minutes for the first hour, then every hour for 7 hours and then daily for 14 days. In a second trial an additional moving treatment was included where replicate beakers were placed on laboratory benchtop rockers (moving) and floating seeds recorded every hour for 14 hours, then 1 to 5 times daily. Prior to each count, each beaker was stirred for five seconds. The results of both tests using seed lots from the Pinnacles are shown in Figure 2. Figure 2. Mean percent of C. odorata seed (Pinnacles) floating in two laboratory tests.

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Despite the different recording schedules and moving treatment, 50% of both seed lots sunk in the first 7 to 8 hours and 95% sunk in 48 to 96 hours. However a long tail was evident, with the last seed not sinking until after 350 hours (still water test 2). The dispersal distance will reflect the speed of the water flow and the chance of establishment will depend on the seed reaching a suitable habitat.

People and vehicles (anthropochory)

Figure 3 shows all the location points recorded for C. odorata in the Townsville area. The concentration of points along tracks/roads and along creek/river systems as well as more scattered infestations throughout the area suggests that many dispersal mechanisms including wind, water, people and vehicles are contributing to the spread of C. odorata. In the Townsville area, recreational traffic on both private and public land is also considered to contribute to spread particularly from river banks and easements accessed by motor bikes, quad bikes or four wheel drives. The seed has rows of fine hairs (Figure 1), which assists adhesion to clothing and backpacks. Chromolaena odorata can adhere to clothing if walking through an infestation and then be transported in vehicle cabins via contaminated equipment or clothing.

Figure 3. Overview of all the C. odorata (green points) recorded in the Townsville area, not all local points are included after 2012 and some plants have been controlled. Dark

blue lines are the river basin boundaries, green lines are protected areas and black lines are major roads. Insets; Creek lines are light blue and C. odorata points follow the Alice 156 River running south to north, some points are near Herveys Range Road running east – west. Page

Chromolaena odorata plants have also been recorded near industrial sites extracting commodities such as sand, rock and timber. In addition to the ground disturbance resulting from resource extraction, there are also risks associated with extraction equipment and vehicles moving contaminated material to other locations.

Animals (epizoochory and endozoochory)

While not studied directly or through the use of surrogate seeds, the adhesion of seed to animals (epizoochory), particularly mammal fur is also possible (Gautier 1993) given the seed structure (Figure 1 inset). No information on the viability of seed after passing through the gut (endozoochory) has been identified, but plants have been observed with browsing damage from grazing stock.

DISCUSSION

Local trials and observations suggest that regular wind dispersal is likely to be limited to the vicinity of infestations but water is less of a barrier to dispersal and the seeds have features that increase the likelihood of adhesion to clothing or fur. Field sampling by Blackmore (1998) found most wind dispersed C. odorata seed landed within the infestation with increasingly smaller amounts of seed recovered up to 80 m away from the infested edge. The same study also showed that a contaminated vehicle repeatedly harboured seed after driving 4 and 15 kilometres. Historically the movement of people and military equipment around south-east Asia and the Pacific was seen as a more likely mechanism of long distance dispersal than wind (McFadyen 2002). Gautier (1993) cites a local thesis that found the spread rate of C. odorata along roadsides is more likely to involve agricultural vehicles and less likely as a result of wind dispersal. The transport of contaminated crops is regarded as a source of introduction and spread (CABI (2017). These examples highlight the importance of clean down and inspection procedures, as well as restrictions on vehicle movement and access. The seed is small, light and pointed with rows of fine hairs (Table 1 and Figure 1), so clean downs should also include the vehicles cabin and field equipment. There is also a risk of dispersal via walkers in natural areas and recreational users of aquatic areas. Contaminated produce or raw materials should be securely transported where feasible. Seed buried below 2 cm will not germinate (Chauhan and Johnson 2008) but seed longevity trials show buried seed will persist longer than surface seed (S. Brooks, M Setter, unpublished data). If seed was buried in contaminated sand, rock or soil then any exposure of buried seed up to seven years after deposition may result in a recruitment event. Much of the linear spread mapped in Figure 3 follows creeks and rivers. So the immersion appears to present little barrier to viable seed dispersal by water, although fresh water 157 dispersal is partly limited by a 50% reduction in buoyant seed over the first 8 hours. The obvious potential for future dispersal down fresh water systems should be reflected in

future management priorities. As with water and other dispersal mechanisms, a suitable Page

habitat is required for C. odorata seed to germinate and establish. Roads, rivers and water extraction from contaminated sources provide both seed dispersal vectors and suitable habitats in the form of increased soil moisture and reduced ground competition. Rail and water infrastructure corridors provide opportunities for C. odorata dispersal and establishment where a suitable habitat is reached. The distance and direction of anthropocentric dispersal is difficult to determine. Activities such as supressing seed production in publicly accessible places, early detection and maintaining effective entry protocols on land parcels should contribute to lowering the overall risk of spread and establishment. There is an inherent danger in focussing on one dispersal mechanism when several could interact within each infestation. The variety of dispersal methods operating locally over several decades has made, and will continue to make the entire C. odorata incursion hard to manage. However, there is considerable survey and control experience that can be put towards managing new and small infestations. Strategic control, preventing spread and the early detection of new infestations are activities that can limit the overall expansion and impacts of the incursion.

ACKNOWLEDGEMENTS Experimental and seed collection assistance was provided by Katie Patane, Melissa Setter Judy Clark and Jodie Bocking. Mapping data was collected by many DAF and stakeholder field personnel. Joe Scanlan and Shane Campbell commented on the draft manuscript.

REFERENCES Blackmore, A. C. (1998). Seed dispersal of Chromolaena odorata reconsidered. Proceedings of the Fourth International Workshop on Biological Control and Management of Chromolaena odorata, pp. 16–21. CABI, (2017). Chromolaena odorata In: Invasive Species Compendium. Wallingford, UK: CAB International. www.cabi.org/isc. Chauhan, B. S. and Johnson, D.E. (2008). Germination ecology of two troublesome Asteraceae species of rainfed rice: Siam weed (Chromolaena odorata) and coat buttons (Tridax procumbens). Weed Science 56, 567-73 Carrière, S.M., André, M., Letourmy, P., Olivier, I. and McKey, D.B. (2002). Seed rain beneath remnant trees in a slash-and-burn agricultural system in southern Cameroon. Journal of Tropical Ecology 18, pp. 353-74. Coleman, J.R. (1989). Embyrology and cytogenetics of apomictic hexaploid Eupatorium odoratum L. (Compositae). Review of Brasil Genetics 12, 4. 803-17. Gautier L, 1993. Reproduction of a pantropical weed: Chromolaena odorata (L.) R. King & H. Robinson. Candollea, 48:179-193. McFadyen, R.E.C. (2002). Chromolaena in Asia and the Pacific: spread continues but control prospects improve. In: Zachariades C, Muniappan R, Strathie LW, eds. Proceedings of the Fifth International Workshop on Biological Control and Management of Chromolaena odorata. Pretoria, South Africa: ARC-Plant Protection Research Institute, 13- 18. 158

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EXTENDING FLUPROPANATE USE – SPOT APPLICATION ON PERENNIAL MISSION AND GAMBA GRASS

Wayne Vogler1, Emma Carlos1 and Kelsey Hosking1 1Biosecurity Queensland, Department of Agriculture and Fisheries, Tropical Weeds Research Centre, P.O Box 187 Charters Towers, Queensland 4820, Australia.

ABSTRACT

Perennial mission grass (Cenchrus polystachios) and gamba grass (Andropogon gayanus) are two highly invasive grasses present in north Queensland. Currently, herbicide control options for these species are limited to non-selective herbicides such as glyphosate that result in significant off-target damage. In this study, field trials were conducted to investigate the efficacy of spot applications of flupropanate (liquid and granular) into the tussock as a selective herbicide option for these grasses. Australian Pesticides and Veterinary Medicines Authority (APVMA) approval will be sought for the use of: 4.5 g/tussock of GP Flupropanate and 0.6 ml/tussock of Tussock™ for perennial mission grass control; and 9 g/tussock of GP Flupropanate and 1.2 ml/tussock of Tussock™ for gamba grass control. These rates were selected as the most efficacious, although efficacy was not significantly higher than lower rates, it is expected that these rates will be more effective under marginal conditions. In summary, spot application of flupropanate is an effective and practical method for controlling these invasive grasses with particular application in areas such as revegetation sites, sites in the early stages of invasion with limited or scattered infestations and sites where the northern wet season can limit access for high-volume herbicide application.

Keywords: Flupropanate, perennial mission grass, gamba grass, spot application.

INTRODUCTION

Perennial mission grass (Cenchrus polystachios) and gamba grass (Andropogon gayanus) are two highly invasive grasses present in north Queensland. Perennial mission grass remains undeclared in Queensland though in the Northern Territory it is a Class B and Class C weed under the Weeds Management Act 2001. Gamba grass is listed as category 3 restricted matter under the Biosecurity Act 2014 in Queensland and recognised as a Weed of National Significance in Australia. Each of these grasses compete strongly with native pasture and their high biomass can fuel intense bushfires that damage ecosystems and threaten the safety of people and property (Department of Agriculture and Fisheries, Biosecurity Queensland 2016, Northern Territory Government of Australia 2017). Despite the significant negative impacts of these grasses, herbicide control options are limited. Most registered herbicides are non-selective, such as glyphosate, and can cause non-target damage, or mortality, to surrounding desirable species. This can reduce competition for invasive species and leave areas open to further invasion. With this in mind, a selective herbicide could greatly improve management of these invasive grasses.

Flupropanate is a selective, soil-active, residual herbicide that requires rainfall to enter the soil and be absorbed through the root system of plants. A single application has the 159 potential to control mature plants and germinating seedlings, although effectiveness and timeframes will vary depending on soil type and rainfall. The effect of flupropanate on Page

perennial mission and gamba grass is not known, although anecdotes suggest that it may be useful for their control. This trial investigated whether individual perennial mission and gamba grass tussocks could be effectively controlled with a single spot application of liquid or granular flupropanate.

METHODS

The herbicides Tussock™ (745 g/L flupropanate) and GP Flupropanate (86.9 g/kg flupropanate) were used for all liquid and granular flupropanate treatments respectively. All trials were established in October 2013 using a completely randomised block design. Experimental units comprised 4 m x 4 m plots, with each treatment replicated four times.

Perennial mission grass

The trial site (16°57’53.42”S, 145°24’33.43”E°) was located within a grassy woodland where patches of perennial mission grass had established. Plots contained an average of 15 perennial mission grass plants, with mean basal diameters of 15.8 cm. Tussock™ and GP Flupropanate were tested at 0.3, 0.6 and 1.2 ml/tussock; and 2.25, 4.5 and 9.0 g/tussock respectively for efficacy against a control (no flupropanate). The respective rates of each formulation contained the same amount of active ingredient. Measured doses of Tussock™ and GP Flupropanate were applied to the centre of all tussocks in each plot. Tussock™ treatments were applied with a N.J. Phillips® 5 ml Tree Injector as a single 4 ml shot of herbicide/water solution per tussock while GP Flupropanate treatments were hand applied.

Herbicide efficacy was assessed at 106 and 183 days after treatment (DAT) by rating each tussock as alive or dead. Mortality (%) was analysed, and this was calculated as the number of dead tussocks over the total number of treated tussocks. The impact of herbicide treatments on adjacent non-target grasses and broadleaf plants was assessed by measuring the distance (cm) between treated tussocks and the nearest non-target grass and broadleaf plant that was alive. At 183 DAT, the total number of stems with emerged seed heads was counted in each plot.

Gamba grass

The trial site (16°58’58.28”S, 145°15’49.53”E°) was located on cleared agricultural land dominated by gamba grass. Plots contained an average of 30 gamba grass plants, with mean basal diameters of 12.9 cm. Prior to the commencement of the trial, cattle had grazed the site, making tussocks accessible and easily treated on an individual basis. Cattle were excluded for the duration of the trial. Tussock™ and GP Flupropanate were tested using the application rates and methodology used for perennial mission grass (see above).

Herbicide efficacy was assessed at 133 and 182 DAT by rating each tussock as alive or dead. However, as there had been significant gamba grass recruitment, gamba grass tussocks that were ≤5 cm in size were considered to have been recruited from seed since treatment application and were not included in the efficacy assessments. Mortality (%) was analysed, and this was calculated as the number of dead tussocks over the total number of treated tussocks. At 182 DAT, the total number of gamba grass stems with 160 emerged seed heads was counted in each plot. Tussocks that were ≤5 cm were also Page

counted in each plot to assess lateral movement and residual effects of the herbicide on ‘new plants’.

Statistical analyses

Randomised complete block ANOVAs (p<0.05) were used to assess treatment effects. Where required, data was transformed (log10 + 0.1) to meet ANOVA assumptions. Means or back-transformation of the geometric means are presented. Treatment means were separated according to Fisher’s Protected LSD (p<0.05).

RESULTS

Perennial mission grass

Mortality of perennial mission grass tussocks 106 DAT was significantly different between treatments (p<0.001), with nil mortality in controls and the highest and middle herbicide rates having similarly high mortality (Table 1). There was an increase in mortality over time and by 183 DAT, mortality of tussocks remained significantly different between treatments (p<0.001). While the highest GP Flupropanate treatment (9.0 g) resulted in the greatest mortality of mission grass, at 183 DAT it was not significantly higher than any other herbicide treatment, except the 2.25 g GP Flupropanate treatment. Stems with emerged seed heads in the control plots averaged 22.6 at 183 DAT which was significantly higher than all herbicide treatments (Table 1) (p<0.001). There was little impact on non- target species at 106 DAT with no significant difference (p>0.05) between the control and herbicide treatments in the average distance from a treated tussock to the nearest live non-target grass or broadleaf plant, which averaged 9.19 cm.

Table 1. Mean tussock mortality and number of stems with emerged seed heads per plot. Means within columns followed by the same letter are not significantly different (p>0.05). Tussock mortality Tussock mortality Number of stems with emerged Treatment Rate 106 DAT (%) 183 DAT (%) seed heads per plot 183 DAT Control NA 0.0 d 13.6 c 22.6 a Tussock™ 0.3 ml 45.6 bc 83.9 ab 3.6 b Tussock™ 0.6 ml 77.7 a 90.9 a 0.9 b Tussock™ 1.2 ml 89.8 a 87.9 ab 1.0 b GP Flupropanate 2.25 g 36.6 c 65.7 b 5.0 b GP Flupropanate 4.5 g 68.5 ab 87.5 ab 0.9 b GP Flupropanate 9.0 g 78.0 a 97.3 a 4.8 b

Gamba grass

There was a significant treatment effect on mortality of gamba grass tussocks 133 DAT (p<0.05). In control plots, all initial plants remained alive, compared to the herbicide treatments where >60% mortality was recorded (Table 2). The two highest rates of GP Flupropanate had significantly higher tussock mortality than the lowest Tussock™ rate, while tussock mortality was not significantly different between all other treatments (Table 2). There was a significant difference in the number of new plants (<5 cm in size) between treatments (p<0.05), with the Tussock™ treatments generally having fewer new plants compared to the GP Flupropanate treatments and controls (Table Table 2). There was on 161 average 42.8 stems with emerged seed heads in the highest GP Flupropanate treatment at 182 DAT which was significantly fewer (p<0.05) than in all other treatments (Table 2). Page

Table 2. Mean tussock mortality, number of new plants and number of stems with emerged seed heads per plot. Means or back transformations of geometric means (*) within columns followed by the same letter are not significantly different (p<0.05). Tussock mortality Number of new plants Number of stems with emerged Treatment Rate 133 DAT (%) per plot 133 DAT seed heads* per plot 182 DAT Control NA 0.0 a 8.3 b 215.0 a Tussock™ 0.3 ml 61.1 b 5.8 ab 164.3 a Tussock™ 0.6 ml 67.3 bc 1.3 a 107.5 a Tussock™ 1.2 ml 78.6 bc 6.5 ab 147.0 a GP Flupropanate 2.25 g 83.0 bc 10.5 b 301.8 a GP Flupropanate 4.5 g 88.7 c 9.8 b 280.8 a GP Flupropanate 9.0 g 92.0 c 10.8 b 42.8 b

DISCUSSION

Spot application of at least one rate of each herbicide was effective for controlling perennial mission and gamba grass tussocks, although gamba grass generally required higher rates to achieve satisfactory mortality. Even then, mortality averaged less than 80% using Tussock™ which is towards the lower range for acceptable herbicide efficacy. Lateral movement of herbicides from treated tussocks appeared negligible, with no impact on adjacent plants. Emergence of new gamba grass plants also suggested no residual impact on areas surrounding tussocks. Follow up treatment will be essential to control emerging seedlings.

While not practical on a large scale or for dense monocultures, spot application of flupropanate products has a place in control of perennial mission and gamba grass. The high-concentration low-volume method of applying Tussock™ provides a treatment option for hard to access areas where using heavy spray equipment is impractical. GP Flupropanate offers the opportunity to immediately treat tussocks encountered by chance as its granular formulation is easily portable and does not require mixing or dilution. All flupropanate products are soil-active and require rainfall to enter the soil and be absorbed through the root system of plants. These products can be applied during the dry season and become active in the wet season, allowing control when access to apply herbicides is restricted by weather and road conditions.

Given its advantages, the potential to extend this method to other invasive grasses such as African fountain (Cenchrus setaceus), giant rat’s tail (Sporobolus pyramidalis and S. natalensis) and Guinea grass (Megathyrsus maximus var maximus) warrants investigation.

Spot application of flupropanate provides an effective and practical method for controlling both perennial mission and gamba grass in areas such as revegetation sites, sites in the early stages of invasion with limited or scattered infestations and sites where the northern wet season can limit access for herbicide application. A minor use permit application will be submitted to the Australian Pesticides and Veterinary Medicines Authority (APVMA) to extend the control options available to land managers for these invasive grasses.

ACKNOWLEDGMENTS

162 The authors thank John Clarkson (Queensland Parks and Wildlife Service) and Sid Clayton (Mareeba Shire Council) for their support. Thanks also to Shane Campbell and Page

Joe Scanlan for commenting on earlier versions of this paper. Funded by the Department of Agriculture and Fisheries.

REFERENCES Department of Agriculture and Fisheries, Biosecurity Queensland (2016) ‘Gamba grass, Andropogon gayanus’. https://www.daf.qld.gov.au/__data/assets/pdf_file/0011/67466/IPA-Gamba-Grass- PP147.pdf. (Queensland Government, Brisbane).

Northern Territory Government of Australia (2017) ‘Mission grass’. https://nt.gov.au/environment/weeds/list-of-declared-weeds-in-the-nt/mission-grass. (Northern Territory Government of Australia, Darwin).

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FROM PRICKLY ACACIA TO PASTURE – KEY LESSONS FROM A MECHANICAL CONTROL FIELD STUDY

Nathan March1 and Samantha Cullen2 1Biosecurity Queensland, Department of Agriculture and Fisheries, P.O. Box 53 Cloncurry, Queensland 4824, Australia. 2Southern Gulf NRM, P.O. Box 2211 Mount Isa, Queensland 4825, Australia

ABSTRACT As a result of years of community, industry and government research and innovation, a range of herbicide and mechanical options are available for the control of prickly acacia (Vachellia nilotica). However, in recent years, mechanical control options have become less favoured due partly to the perceived risks of mass prickly acacia germination and the high follow-up control requirements.

A field study, conducted during 2015 – 2017 at a property near Richmond in north-west Queensland, examined pasture and seedling responses to mechanical control (dozer pushing) of mature prickly acacia. Results were compared with adjacent untreated (control) sites. Prickly acacia seedling counts were initially higher in pushed areas but due partly to ensuing low rainfall, no new saplings have established at either site during the study. Average pasture cover increased from 1.4% to 30% and 3.2% to 53.4% at the untreated and dozer pushed treatment sites respectively. In this case, the landholder gained prickly acacia foliage fodder and improved pasture cover in the following years with negligible follow-up control.

The study demonstrates the benefits of mechanical control of prickly acacia if undertaken in the right circumstances.

Keywords: Prickly acacia, Vachellia nilotica, mechanical control

INTRODUCTION Trial and control program results have determined mechanical control to be an effective and efficient option for prickly acacia (Calvert 2011, Jeffrey 2004). March (2000) highlighted the advantages of mechanical control as including : provision of drought fodder, immediate kill rates, reduced labour requirements, and property management benefits (e.g. improved mustering and property access). He also noted the risk that ‘massive seedling emergence

may occur if used around permanent waters and drainage lines.’ 164

While various mechanical control trials have occurred since the 1990s, no studies have monitored both pasture and seedling responses over several years following mechanical

treatment. An opportunity to study pasture and seedling response to mechanical control Page

occurred when a landholder undertook dozer pushing of prickly acacia on a property in mid-2014. The aim of the study was to compare pasture cover and prickly acacia seedling germination and survival in treated and untreated sites over a number of years. The study was part of the Queensland Government initiated War on Western Weeds project.

MATERIALS AND METHODS The field site is located within the Mitchell grasslands of north-west Queensland on ‘Chatfield Station’ near Richmond. Prickly acacia on the site was dozer pushed by the landholder to obtain supplementary drought fodder. Prickly acacia density was not assessed prior to treatment but estimated to have been high, with 150–250 trees per hectare. The study site comprised an area of dozer pushed (treated) prickly acacia trees and an adjacent area of untreated trees. Twenty mature trees were selected from the untreated and treated areas respectively. Pushed trees were often well removed from where they had being growing. Pushed tree sites were determined by where the plant had grown rather than where they had been pushed. The sites were easily determined by observations of the remaining roots and hollow depressions where the stem-base had been located. The sites were assessed for seedling presence and pasture cover once annually over three years. No benchmark data were available for these measurements before pushing occurred. Assessments were undertaken annually after each wet season (April to early May) when pasture cover and seedling numbers were expected to be relatively high and largely unaffected by grazing. For both treated and untreated sites, seedling counts were undertaken within a 5m radius from the middle of the stem-base of each tree or where the tree had stood prior to treatment. Both live and dead seedlings were recorded. Pasture cover was assessed within twelve 0.5 m by 0.5 m quadrats within a 5m radius of each tree stem-base in both treated and untreated sites. Six quadrats were placed at 0, 1.5, 3, 6.5, 8 and 9.5m on a north to south line starting 5 m from the centre of each stem-base with the remaining six quadrats placed similarly in an east to west line. Pasture cover percentages were estimated using a visual guide sheet.

RESULTS Seedling germination and establishment Prickly acacia seedling counts were initially higher in treated sites than untreated sites. In 2015, 293 seedlings were found in the treated site while 96 were found in the untreated site – a difference of 205%. However, none of the seedlings were alive in the untreated site and only 62 (21%) of the 293 from the treated site were alive. In the 2016 seedling assessment, none of the 62 seedlings found in 2015 had survived. Additionally, due to the ongoing low rainfall conditions, there was only one new seedling (dead) found at the treated site and none at the untreated site.

In 2017, even after rainfall above the long term annual average of 475 mm at Richmond (Bureau of Meteorology 2017) (Figure 1), only 21 seedlings were found at the untreated 165 site and none at the treated site. Seedling data across all years is provided in Table 1.

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Figure 1. Monthly rainfall graph for the duration of the field study (BOM 2017).

Table 1. Seedling counts (both live and dead) at untreated and treated sites

Monitoring year Untreated sites Average no. Treated sites Average no. seedlings at seedlings at Total seedlings Total seedlings untreated sites treated sites 2015 96 4.8 293 15 2016 0 0 1 0.1

2017 21 1.1 0 0

Pasture cover

Pasture cover was very low for both untreated and treated sites when monitoring first occurred in April 2015, with averages of 1.5% and 3.1%, respectively. Given the lack of rainfall for the first wet season after pushing, it can be reasonably assumed that pasture cover was not overly different to 1.5 % at the time of treatment with a marginal pasture cover increase for the pushed area due to increased available soil moisture following tree removal.

Rainfall was low in the following year but yielded minor improvements to pasture cover when assessed in 2016 (Figure 2) with averages of 3.2% and 7.0% for untreated and treated sites respectively.

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Figure 2. Pasture response and cover following the modest rainfall of the 2015 - 2016 wet season was much lower for untreated (left) than treated sites (right).

Above average rainfall over the 2016 - 2017 wet season brought significant pasture improvements to both sites, with average cover of 30% and 53.4% for untreated and treated sites respectively (Table 2) (Figure 3). No data were recorded to quantify the composition of plant species present or their relative grazing values. However, it is noted that less desirable herbage (eg. soft roly-poly, Salsola kali) contributed significantly more to pasture cover in untreated sites than treated sites.

Table 2. Average pasture cover (%) at untreated and treated sites over 2015 - 2017

Monitoring year Untreated sites Treated sites Average pasture cover Average pasture cover (%) (%)

2015 1.4 3.2

2016 3.2 7.0 2017 30.0 53.4

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Figure 3. Pasture cover recordings over the duration of the study with lines representing average pasture cover of the untreated and treated sites.

DISCUSSION

The higher numbers of prickly acacia seedlings recorded for treated sites in the year after treatment was to be expected given the increased germination potential from ground disturbance, increased moisture availability due to tree removal and shelter provided to seedlings from fallen timber. It is also noted that some seedling clumps were observed emerging from cattle manure with this seed likely sourced elsewhere and not actually from the trees within the study.

Due partly to extended periods of low rainfall, no new prickly acacia saplings have established at either site during the study. It is nevertheless surprising that with improved rainfall (465 mm recorded from December 2016 to April 2017) that no seedlings (live or dead) were found at the treated sites in 2017. This may be explained by increased competition for moisture associated with increased pasture cover, reduced soil seed loads and, to a lesser degree, the greater difficulty of finding seedlings in high pasture cover.

In this study, the landholder has gained foliage fodder of prickly acacia through dozer pushing and improved pasture cover in the following years with negligible follow-up control. Key lessons include the need to consider the timing and season of mechanical control and the targeting of areas with lower soil seed loads.

While the use of mechanical control options may potentially increase the risk of seedling 168 germination and survival in higher rainfall years, these results indicate it can also yield Page

significant benefits without the need for excessive follow-up control when undertaken at preferential times such as during extended low rainfall periods.

ACKNOWLEDGEMENTS

The authors thank Robert Flute, Chatfield Station, Richmond for access to the property and rainfall records for this study. Assistance with site monitoring was provided by Dana Quirk (DC Quirk Contracting) and Edward Brown (Southern Gulf NRM). Thanks also to Wayne Vogler for providing advice on experimental design and data analysis. Additionally, Wayne Vogler, Steve Csurhes and Kelsey Hosking provided comment to early drafts of this paper.

REFERENCES

Bureau of Meteorology (2017). Climate statistics for Australian locations, Richmond Queensland. http://www.bom.gov.au/climate/averages/tables/cw_030045.shtml. (Bureau of Meteorology, Australian Government)

Calvert, G. (2011) Prickly acacia eradication project, NQ Dry Tropics, Townsville.

Jeffrey, P. (2004). Development and adoption of best practice – the research years. In Spies, P. and March, N.A. (eds). Prickly acacia national case studies manual: approaches to the management of prickly acacia (Acacia nilotica subsp. indica) in Australia. Department of Natural Resources, Mines and Energy. pp. 14 – 18.

March, N.A. (2000). Prickly acacia best practice manual: control and management options for prickly acacia (Acacia nilotica ssp. indica) in western Queensland, Department of Natural Resources.

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