Category Archives: Weed issues & solutions

Plant communities of seasonal clay-based wetlands of south-west Australia: weeds, fire and regeneration

Kate Brown and Grazyna Paczkowska

Key words: regeneration, fire, seasonal wetlands

 While the majority of seasonal wetlands in south-west Australia are connected to regional ground water, some found on clay substrates rely solely on rainwater to fill. These seasonal clay-based wetlands fill with winter rains and are characterised by temporally overlapping suites of annual and perennial herbs that flower and set seed as the wetlands dry through spring. Over summer the clay substrates dry to impervious pans. The seasonal clay-based wetlands of south-west Australia comprise a flora of over 600 species, of which at least 50% are annual or perennial herbs, 16 occur only on the clay-pans and many are rare or restricted.

These ecological communities are amongst the most threatened in Western Australia and have recently been listed under the Commonwealth Environmental Protection and Biodiversity Conservation Act as critically endangered. Over 90% have been cleared for agriculture and urban development and weed invasion is a major threat to those that remain. South African geophytes are serious weeds within these communities and Watsonia (Watsonia meriana var. bulbillifera) in particular can form dense monocultures and displace the herbaceous understorey.

Watsonia invading  a seasonal clay-based wetland

Watsonia invading a seasonal clay-based wetland

Regeneration following weed control and fire.  We investigated the capacity of the plant community of such a wetland to regenerate following removal of Watsonia, and the role of fire in the restoration process.

 Our study site, Meelon Nature Reserve, is a remnant clay-based wetland on the eastern side of the Swan Coastal Plain 200 km south of Perth. A series of transects were established in August 2005 and regeneration of plant community following Watsonia control and then unplanned fire was monitored until September 2011 (Table 1).

 Table 1: Six years of monitoring regeneration of a seasonal wetland at Meelon Nature Reserve

August 2005 Thirty 1m x 1m  quadrats established along five 30m transects in the wetlands where Watsonia was estimated to average greater that 75% cover.
September 2005 Cover ( modified Braun Blaquet) recorded for all native and introduced taxa and then Watsonia treated with the herbicide 2-2DPA (10g/L) + the penentrant Pulse® (2.5 mL/L).
September 2006 Cover recorded for all native and introduced taxa and then Watsonia treatment reapplied.
February 2007 Unplanned wild fire burnt across the study site.
September 2007  each year until September 2011 Cover recorded for all native and introduced taxa and then any Watsonia treated.

Analysis of similarity (ANOSIM) was undertaken to determine if there was significant change in species cover and composition from before Watsonia control to six years following the initial treatment. A  SIMPER analysis was used to ascertain the contribution of each species to any changes between monitoring years (Clarke & Gorley 2006).

Results. In the first year of the control program, a 97% reduction in the cover of Watsonia was recorded, but was associated with no significant change in the diversity or abundance of native flora. In February 2007, 18 months after the initial control program, an unplanned summer wildfire burnt through the reserve. In September 2007 monitoring revealed a significant increase in cover and diversity of native species in the treatment areas. Some species such as the Dichopogon preissii had not been recorded before the fire, others, such as the native sedges, Cyathochaeta avenacea and Chorizandra enodis increased greatly in cover following the fire. At the same time there was no resprouting of Watsonia or recruitment from cormels or seed.

Six years after the initial treatment the native sedges and rushes continue to increase in cover, the dominant native shrub Viminaria juncea is increasing, Eucalyptus wandoo seedlings are recruiting into the site and native grasses and geophytes are increasing in cover. The indications are that plant communities of the seasonal clay-based wetlands of south-west Australia have the capacity to recover following major weed invasion and that fire can play a role in the restoration process.

Table 2. Species that contributed to 90% of the significant change in cover and composition of species between 2005 and 2011.

 

2005

2011

Species

Average abundance (% cover)

Average abundance (% cover)

Cyathochaeta avenacea

10.0

23.5

Chorizandra enodis

2.3

15.7

Viminaria juncea

2.1

15.4

Caesia micrantha

2.6

2.7

Briza sp. Meelon

3.1

2.0

Eucalyptus wandoo

0.0

3.0

Austrodanthonia acerosa

0.4

1.8

Hypoxis occidentalis

0.0

1.9

Lepidosperma sp. WT2Q5 Meelon

0.1

1.3

Meeboldina sp. MU3 Meelon 2011

0.2

1.4

Dichopogon preissii

0.0

1.3

Drosera rosulata

1.5

0.2

Contact: Kate Brown, Ecologist, Swan Region. Department of Environment and Conservation, PO Box, 1167 Bentley Delivery Centre, WA, 6983. Email: kate.brown@dec.wa.gov.au

Chorizandra enodis

Chorizandra enodis

Dichopogon preissii

Dichopogon preissii

Hypoxis occidentalis

Hypoxis occidentalis

Macquarie University – Turpentine/Ironbark forest Regeneration

John Macris 

Key words: Bush Regeneration, Privets, Pittosporum, in-situ conservation.

Less than 5% of the original extent of Turpentine/Ironbark forest of the Sydney Basin Bioregion remains and so this forest type is listed is listed as critically endangered under the Commonwealth EPBC Act. Weed management and rehabilitation of remnants are priority conservation actions under the Act.

A 3.5 ha remnant of Turpentine/Ironbark forest located on the Macquarie University Campus has been the focus of a bush regeneration program that commenced in 2010.  Prior to the works, the site was variable in condition, with a core area near a watercourse having relatively high species diversity including Blackthorn (Bursaria spinosa) and the rare shrub Epacris purpurascens, while edges of this area contained a diversity of weed species.  An upslope area was more highly disturbed as it had been used as a breeding enclosure for research into rare rock wallabies until around 2005.

Works to date. Commencing in Autumn 2010, contract bush regeneration works included culling of the over-represented native Sweet Pittosporum (Pittosporum undulatum) in the core area, and removal of invasive weeds, principally a dense mid-story of the woody weeds Large-leaved Privet (Ligustrum lucidum) and Small-leaved Privet (L. sinense) throughout the treatment area.  Any large Privet logs were retained as habitat. Pampas Grass was removed from around the perimeter and, in a few places, Lantana  (Lantana camara) was also removed, although some has been retained as an interim small bird habitat in a few locations. Follow up work has mainly focused on a range of herbaceous weeds including Ehrhardta (Ehrhardta erecta), and gradual exhaustion from the seed bank of the problem woody weed species.

Results Prior to works, we estimated that about 10% of remnant was in relatively good condition.  About 2.5 years on, we now estimate that about 15% – 20% of the area is now in a resilient condition. Native species regenerating include a range of native grasses and forbs including Blady Grass (Imperata cylindrica), Basket Grass (Oplismenus aemulus), Weeping Grass (Microlaena stipoides), Tufted Hedgehog Grass (Echinopogon caespitosus),Blue Flax Lily (Dianella caerulea), Plume Grass (Dichelachne sp.), Finger Grass (Digitaria parviflora) Bordered Panic Grass (Entolasia marginata), Pastel Flower (Pseuderanthemum variabile) and Kidney Weed (Dichondra repens). Tree saplings including Turpentine (Syncarpia glomulifera) and Smooth-barked Apple (Angophora costata) have been uncovered and are developing in height. The colonizing shrub Kangaroo Apple Solanum aviculare has rapidly developed a rudimentary native mid story in the areas cleared of dense Privet.

Woody weed domination of the understorey before the works commenced

Same view 2years later (2012) showing ground stratum regeneration

Lessons learned. To create a robust weed buffer to the regeneration area, we decided it was important to start work in upslope areas, even though they were disturbed by the previous animal research enclosure (e.g. artificial soil profiles).  Due to same competing uses, such areas have been challenging stablise against weed resurgence, but a management edge is being established gradually.

Acknowledgements.  Sixty per cent of the first 15 months funding for the project was provided by Sydney Metropolitan CMA through their Saving Sydney’s Biodiversity Program with the rest covered by the University.  Subsequent work has been funded under Macquarie University’s Biodiversity restoration programs. Warren Jack from the contractor Sydney Bush Regeneration Company contributed much of the above species list of ground layer regeneration.

Contact: John Macris, Macquarie University. john.macris@mq.edu.au Tel: +61 (0)2 9850 4103

Regeneration of Lismore bushland cemetery, north coast NSW.

Key Words: bush regeneration, selective herbicides, transplanting, cemetery management

Since 2006, Lismore City Council’s Lismore Memorial Gardens (LMG) has been restoring and managing a 1.5ha  patch of regrowth Forest Red Gum (Eucalyptus tereticornis) grassy open forest in Goonellabah, north coast NSW – primarily for use as a bushland cemetery.  The site was part of a registered Koala corridor  and was in a highly weedy condition prior to the commencement of the project, with the understorey dominated by Lantana (Lantana camara) and most trees having at least one multi-stemmed Camphor Laurel (Cinnamomum camphora) encircling it.

Bush regeneration works. In 2006 the lantana was mechanically cleared and Camphor Laurels were stem-injected with glyphosate herbicide. After woody weed removal, the ground stratum rapidly responded with a germination flush of herbaceous weeds, mainly Blue Billygoat Weed (Ageratum houstonianum), Farmers Friends (Bidens pilosa) and Broad-leaved Paspalum (Paspalum mandiocanum) although some native herbaceous species were also regenerating, particularly Basket Grass (Oplismenus aemulus), Weeping Grass (Microlaena stipoides) and Kidney Weed (Dichondra repens).

Subsequent detailed spot spraying with herbicides was undertaken; in the first few years on a monthly basis by volunteers, and more recently by a horticulture-trained LMG staff member after some workplace tuition in bush regeneration methods.

1. Resilient areas. Herbaceous weed was systematically sprayed with broad-leaf selective herbicides (Dicamba/MCPA plus surfactant) or glyphosate.  Three larger patches consolidated with native species fairly rapidly, while other areas in poorer condition colonised with fewer species or took longer to convert to native dominance.  There are now 69 species on site that  are characteristic of this ecosystem (including 8 tree species, 15 grasses, 5 sedges, 8 twiners/climbers, 5 ferns and 1 moss).  About 20 of these species have been added to the list since the start of the project and all existing species have vastly increased in cover and density. The intermittent watercourse area regenerated over time with wetland herbaceous species largely including Persicaria spp. and Cyperus exaltatus.

View of central area of the site after control of woody weed. (Camphor chipmulch was initially spread in error then later removed to allow natural regeneration)

Same area two years later, showing extensive regeneration of native grasses and forbs

2. Highly weedy edge.  Standard bush regeneration approaches over at least 2 years in an edge site proved intractable due to high weed contamination and low native richness. A trial was conducted in 2009to see if scalping and revegetation (using transplanting and direct seeding ) could reduce the amount of weed control required and improve native vegetation establishment. This involved removal by a grader of 10 cm of the weedy topsoil, with the remaining subsoil broken up with a backhoe and hand raked. Sods containing multiples of 10 species were taken from the healthier parts of the cemetery and transplanted to the raked site in mid- to late-September 2009, resulting in a total of 145 plants in each of three zones (one transplanted only, one transplanted plus direct seeded with 10 species and one neither transplanted nor seeded). Seven weeks later, when germination from the sods had occurred, it was observed that 17 species (i.e. seven more) had been transplanted (Table 1.) Very few individual transplants died.

Top10cm of weedy topsoil removed and subsoil broken up before transplanting native grass and forb sods

Subsequent monitoring found that all the two scalped and revegetated zones, while requiring monthly weed control initially, had consolidated to a very low weed state by 9 months.  There was little visible difference between them except that the seeded one contained two more species not present in the unseeded site. Within 18 months, both zones had very high cover levels of native vegetation, particularly native grasses, and weed control demand was substantially lower than adjacent edge sites treated with conventional spot spray methods alone.  The non-transplanted or seeded zone remained with low species diversity and was more exposed to weed cover.  It has since become an access track and requires higher weed control inputs than the adajacent revegetated areas.

Nine months after transplanting. With some weed control requirement, natives now well established and commencing a process of steady recolonisation

Lessons learned. The bush regeneration treatments have converted a weed-dominated site to a recognisable Forest Red Gum grassy open forest with a diverse understorey. Cemetery operations are ongoing with the condition of the bushland showing an improvement with each year. Evidence of wildlife use of the habitat is increasing. This is due to ongoing management support, continuing volunteer inputs and the deployment of staff with some training in weed and bushland management.  Although a range of highly problematic weeds (including Asian Copperburr,  Acalypha australis, Prairie Grass, Bromus uniloides, and Hairy Commelina, (Commelina bengahlensis ) were initially not adequately addressed and are now requiring additional treatment; the site is now a pleasure to be in and is a wonderful demonstration site for not only restoration techniques but also the district’s grassy understorey species, once so widespread but now rarely conserved .

Contact: Tein McDonald 06 6682 2885 Email: teinm@ozemail.com.au – or Kris Whitney, Manager, Lismore Memorial Gardens, Email:  Kris.Whitney@lismore.nsw.gov.au

Grey Box grassy woodland restoration: Mandilla Reserve, Flagstaff Hill, South Australia

Key Words:  Minimal disturbance, bush regeneration, Eucalyptus microcarpa, volunteer, Bush For Life

The Site:  Grey Box (Eucalyptus microcarpa) Grassy Woodland is listed as an endangered ecological community under the EPBC Act 1999. This ecological community was once widespread on the drier edge of the temperate grassy eucalypt woodland belt of south-eastern Australia. In South Australia, this community occupies less than 3 percent of the area it once did before European settlement. One of the remaining suburban remnants of this community can be found in Mandilla Reserve, Flagstaff Hill, SA. The reserve is surrounded by suburban houses and remains under threat from weed and pest invasion, lack of recruitment of canopy species plus degradation associated with urban encroachment (pollution runoff, rubbish, excessive stormwater). Since 1996 the Bush or Life program together with the City of Onkaparinga have supported community volunteers to care for and manage the bush regeneration work within the reserve. The objective was to restore the highly degraded Grey Box remnant into a woodland community representing the unique diverse vegetation it once housed.

Geoff and Barbara Moss, volunteers at Mandilla Reserve

Works:   Two very dedicated community members adopted the site in 1996 and began visiting on average 3 times per week. They used minimal disturbance bushcare techniques to tackle a carpet of bulb weeds such as Sparaxis (Sparaxis bulbifera), Soursob (Oxalis pes-caprae), Bridal Creeper (Asparagus asparagoides) and Cape Tulip (Moraea flaccida) mixed with highly invasive annual and perennial grass species. In the surrounding degraded areas, some strategic planting was also carried out using Grey Box (Eucalyptus microcarpa), Sticky Hop Bush (Dodonaea viscosa) and Sweet Bursaria (Bursaria spinosa) and local sedge seedlings. Four areas were also hand direct seeded with native grasses to encourage ground cover recruitment and discourage weeds. All seed used was collected on site to ensure local provenance was maintained.

The flourishing Grey Box Grassy Woodland now found on the reserve

Success of the combination of natural regeneration and supplementary plantings

Results After thousands of volunteer hours, extensive regeneration of natives occurred on site. The volunteers’ work has transformed the reserve into a flourishing area of lilies, native grasses and understorey shrubs. Today, the vegetation in the reserve is virtually weed free and even native orchids are beginning to return. In addition, the area that the bushland covers has expanded as a result of the planting and direct seeding. Since these works, natural regeneration has also been observed of native sedges including Senecio, Carex, Juncus and native grasses.

Lessons learned:  Regular follow up for several years is vital to the success of any primary clearance work whether or not minimal disturbance techniques are used. Facilitated regeneration can be successfully used with bush regeneration providing it is strategic and complementary to and considerate of existing natural regeneration processes. Maintenance of the plantings or hand direct seeding is also vital to minimise competition from weeds and ensure their success.

Acknowledgements: This site is owned by the City of Onkaparinga Council and is managed in partnership with Trees For Life who train and support volunteers through its Bush For Life program. Thanks goes to Geoff and Barbara Moss, the site’s main volunteers.

Contact:  Jenna Currie, Bush For Life Regional Coordinator, Trees For Life jennac@treesforlife.org.au

Rotary Park regeneration project, Lismore NSW

Tein McDonald

Key words: Dry rainforest, regeneration, Anredera cordifolia, long term project, flying-foxes.

Rainforest regeneration works at the 11.5 ha dry rainforest remnant, Rotary Park, Lismore, commenced in in June 1985 under the leadership of Keith King, the then Parks and Gardens Supervisor for Lismore City Council, and inspired by the success of John Stockard at Wingham Brush.

The site, surrounded by residential areas and bordered by a main road, was considered (prior to treatment) so degraded by weed vines that many considered it beyond redemption. The canopy was infested with vines including Madeira Vine (Anredera cordifolia), Asparagus africanus and A. plumosus and Morning glory (Ipomoea spp.) (Fig 1).  Within the forest, the ground was blanketed by Tradescantia (Tradescantia fluminensis) and Madiera Vine tuberlings, with Large- and Small-leaved Privet (Ligustrum spp.) dispersed throughout more degraded areas and edges and gaps often dominated by Lantana (Lantana camara).

Works and results. The project initially trialed minimal disturbance techniques promoted by the bush regeneration movement in Sydney but soon found that higher levels of disturbance were needed to trigger regeneration and render the tuberlings of Madeira Vine and other weed susceptible to herbicide spray.  Adapting the Wingham Method to local conditions, Keith King and the regeneration team led by Rosemary Joseph radically transformed the rainforest into a relatively healthy dry rainforest patch over a period of 10-15 years, although primary work in some parts of the site is still not completed.

Lessons learned.  Prior to primary work being completed, populations of  Grey-headed Flying-fox (Pteropus poliocephalus) and Black Flying-fox (P.  alecto) have established roosts in the forest.  This added significantly to the work load as it increased the density and number of weed species, with new species including by Flying-foxes including Giant Devil’s Fig (Solanum chrysotrichum) and tropical fruits such as Guava (Psidium guajava).  When the trees were stripped of foliage by the flying-foxes, the trees were then used as roots by White Ibis (Threskiornis molucca). This contributed additional ammonia which resulted in deteriorated working conditions for regenerators.  While the project remains on a maintenance budget, current budgets have been insufficient to complete the primary work on other parts of the site.

Acknowledgements. The site is managed by Lismore City Council who have funded the project since its inception.

Contact: Rosemary Joseph  c/o Lismore City Council Martin.Soutar@lismore.nsw.gov.au

Canopy Gap at Rotary Park dry rainforest, Lismore in 1987 (prior to restoration works). (Photo Rosemary Joseph)

Same canopy gap at Rotary Park dry rainforest, Lismore in 1988 (1 year after primary clearing). (Photo Rosemary Joseph)

Same  canopy gap at Rotary Park dry rainforest, Lismore in 2006. (Photo Rosemary Joseph)

Fingal Headland Maritime Themeda Grassland Restoration

Keywords: Grassland, Themeda Grasslands on Sea-cliffs and Headlands, headland ecosystems, bush regeneration, Fingal Head Coastcare, Plectranthus cremnus

Kieran Kinney

Fingal Head, whose first inhabitants are members of the Cudginburra Clan, is a famous beauty spot in the far north coast of NSW, heavily utilised for recreation such as fishing, surfing, whale and dolphin watching and family outings. It is estimated that upwards of 50,000 visitors per annum use the site. As a result of this and other impacts including unfettered goat grazing (commencing around the lighthouse in the late 19th century), the site has many management challenges, including extensive gully and rill erosion, trampling of native vegetation, wildflower harvesting and weed invasion.

Prior to treatment, the ground cover layer was almost completely dominated by a form of the exotic Buffalo Grass (Stenotaphrum secundatum) and a suite of other weeds including Bitou Bush (Chrysanthemoides monilifera ssp rotundata). Because similar headlands in the region (Norries Head and Hastings Point Headland) support the State-listed  Endangered Ecological Community Themeda Grasslands on Sea-cliffs and Headlands it is assumed that Kangaroo Grass (Themeda triandra) was native to the site and became locally extinct due to the history of grazing and weed invasion.

Project works: In 2009 Fingal Head Coastcare determined that work to address the serious weed problems should commence and that trials be undertaken to reintroduce Kangaroo Grass.  Several small plots (100m² ea.) were sprayed with herbicide and slashed (Fig 1). Regenerating weed was regularly removed.

Fig 1: Trial plot 1 -  Natural regeneration within patch of treated Buffalo Grass

The plots were sown with Kangaroo Grass seed collected from other headlands in the region. The material used is a genetically distinct coastal form of Kangaroo Grass that exhibits a unique decumbent growth habit. Ripe fruiting culms were distributed in quadrats as well as randomly over the plots.

In addition to the Kangaroo Grass trials, efforts were made to plant a variety of typical Grass and Forbland species, including Golden Everlasting Daisy (Xerochrysum bracteatum), Evolvulus alsinoides and Chamaechrista maritima. These were propagated in the Fingal Coastcare nursery from seed and stock sourced at nearby headlands.

Results. Regeneration of native species  was extensive across the plots (Figures 2a and 2b). Regenerating native species included Prickly Couch (Zoyzia macrantha), Native Violet (Viola banksii), Angled Lobelia (Lobelia alata) Plectranthus (Plectranthus cremnus) and Beach Bean (Canavalea rosea).

Fig 2a: Typical Buffalo Grass infestation prior to commencement of trials.

Fig 2b: Example of regeneration of native grasses Prickly Couch and Blady Grass after works (Plot 1, 2011).

Both the Kangaroo Grass  and the Everlasting Daisy (Figure 3) have since naturalised on the site. However, the plots revealed very poor rates of germination of Kangaroo Grass, approximately 1 in1000. Germination rates were much higher under controlled nursery conditions

Fig 3: Everlasting Daisy re-established and recruiting on Fingal Headland.

Outcomes and lessons learned The low rate of Kangaroo Grass germination is not regarded as a major impediment to the overall success of the project. As natural processes and cycles come into play, it is probable that Kangaroo Grass will become a significant part of the biota on the headland. That is,  achieving the ultimate aim of a Closed Tussock Themeda Grassland is probably unlikely through reintroduction from the seed sowing methods we used, but may occur naturally over time.

The extensive natural regeneration of the threatened Plectranthus cremnus is a major success of the trials.  This herb species is habitat for a local population of Blue-tongue Lizards and Bearded Dragons. It is a major food source for the reptiles, supplementing their animal diet, which may be very seasonal.

Erosion control has been significantly reduced through active intervention, using hard infrastructure in combination with ‘low key’, passive techniques such as strategic plantings and bush debris.

Local school children are involved in the plantings on an ongoing basis, and have picked up vital local knowledge and site ownership along the way. This project has been a major education experience for the Coastcare group, the Tweed Byron local Aboriginal Land Council and many members of the Fingal Head Community who were previously not aware of this Endangered Ecological Community . The trial areas are now a profusion of wildflowers almost the year round and the Coastcare volunteers receive many compliments from the passing public. During working bees on the site considerable energy is devoted to educating the public about the Grasslands in the hope that this will assist in their protection (and also because it is a lot of fun!)  Anyone who visits the site will be captivated by the delicate beauty of the native flora, the awesome scale of the natural scenery and will surely agree that something special is happening here.

Where to from here?: One of the most challenging and pressing issues facing the headland is uncontrolled pedestrian traffic. Although this may be unavoidable to some extent, it is desirable for the long term health of the ecosystem that some control methods be introduced to the site. Trials have been conducted using bush debris with limited success. More permanent methods would have to be carefully designed and implemented in order to blend with the unique aesthetics of the site. Boardwalk construction has been very successful in key areas, however this type of construction is deemed inappropriate for the grassland proper.  Dense vegetative barriers consisting of tussock forming species such as Spiny Mat Rush (Lomandra longifolia) and Knobbly Club Rush (Isolepis nodosa) are being planted to rationalise the trackways and guide pedestrians away from more sensitive areas.

In terms of the vegetation restoration works, ongoing and extensive follow-up weed control is required and it is envisaged that as each plot is stabilised and achieves manageable levels of autonomy, new areas will be opened up for weed control. It is recommended that a formal Restoration Plan be developed and implemented, perhaps through funding avenues or the involvement of Environmental Science students. This would greatly assist guiding the works over an extended period and help achieve the best possible outcomes for Fingal Headland and the wider community.

Partners and Investors: Fingal Head Coastcare Inc. consulted with the Tweed Shire Council, The Tweed Byron Local Aboriginal Land Council and a number of community groups to plan this project. The community groups include the Fingal Heads Community Association, the Fingal Head Public School, Fingal Rovers SLSC, local businesses and other Tweed Coast Dune care groups.

Contact : Kieran Kinney,  Fingal Head Coastcare Project Manager, 28 Kurrajong Ave Cabarita Beach 2488. Tel:  +61 266763002 Mob: 0457356175.   Email : kierankinney@gmail.com

More than a decade of bush regeneration at the Wootha Nature Refuge

Key words: Rainforest restoration, assisted regeneration, Nature Refuge, bush regeneration industry funding models

Spencer Shaw

Rainforest restoration work has been carried out at Wootha Nature Refuge since the property was purchased by its current landholder in the early 2000s.

The property, located on the Blackall Range in the Sunshine Coast region of south east Queensland,  contains a mix of pasture on the higher gently sloping ground and remnant rainforest community (Regional Ecosystem 12.8.3) on the escarpment below the range. When works started on this site the rainforest was highly fragmented, with Lantana (Lantana camara) dominating the gullies and patches of Broad-leaved Privet (Ligustrum lucidum) dominating the areas between the rainforest patches. 

Figure 1. Landscape context, Wootha NR is on the southern slopes of the Blackall Range. Greater than 90% of the plateau vegetation has been cleared.

The landholder has undertaken substantial restoration works, complementing his formal protection of the remnant and restoration areas under in-perpetuity agreements with both Local and State Governments (through a Voluntary Conservation Agreement (VCA) and Nature Refuge (NR)).

Works undertaken. Works have been undertaken by Brush Turkey Enterprises since 2002 on a monthly to fortnightly basis for the whole of the last decade. 

The initial control works consisted of the poisoning Broad-leaved Privet in-situ for a 500m strip along the western boundary. The technique employed for control of the Broad-leaved Privet early in the project was “frill & paint” (i.e. stem injection). This was undertaken with a small axe cutting 100mm wide cuts into the bark and allowing 100mm spacing, covering two full circumferences of each tree trunk. Herbicide was applied via a squirt bottle of 1:1 glyphosate 360 and water. Our contemporary control technique is a modification of this technique using small arbor chainsaws. 

Figure 2. Lantana camara control in gullies 2005.

Subsequent contract Bush Regeneration works have been relatively low key over the last 10 years, with as little as eight Bush Regenerator days per year – and have focused on the control of Lantana in the gullies to control exotic vegetation and facilitate rainforest pioneer recruitment.  Lantana control has been undertaken using the “track and overspray” technique. Tracks are cut with both brushcutters or fern hooks and glyphosate 360 herbicide is applied by backpack sprayers at a 1:100 dilution with water. Lantana works are preferably undertaken in winter months, due to access difficulties.

Results. Regeneration in the areas previously dominated by Broad-leaved Privet was rapid.  Many species recruited to re-establish a diverse native edge to the rainforest remnant areas; including rare species such as the Threadybark Myrtle (Gossia inophloia).

Approximately 2 ha of Lantana in the gullies have been replaced by naturally regenerating vegetation including species such as as Bleeding Heart (Homalanthus nutans), Black Wattle (Acacia melanoxylon) and Giant Stinging Tree (Dendrocnide excelsa).

Figure 3. Dendrocnide excelsa recruitment. Also shows Basalt scree slopes which dominate this part of the escarpment.

Lessons learned. Until the early 2000s all funding for ecological restoration works in South-east Queensland were linked to ‘trees planted’, and only allowed for revegetation projects. The novel approach taken by the funding program that the works were initially supported by was to require recipients to quantify ‘trees established’ rather than ‘trees planted’ and it also considered eligible, projects that used natural regeneration as a revegetation method.  As such, the Wootha project was the first in our area to employ bush regenerators to facilitate natural regeneration of native ecosystems.

We consider this project to be a good example of what can happen if there is consistency of follow up undertaken (even if limited) over a long time period.  Too often projects undertake the ‘primary’ clearing of a site but undertake little or no ‘secondary’ or follow-up work.  Although relatively minor annual works take place on this site, the ongoing nature of the funding for this project and hands on involvement by the landholder provides for the steady and incremental restoration of the rainforest. This is achieving actual and long-term success.

Acknowledgements. Funding for our works came initially through the SE QLD Rainforest Recovery Project and later through the VCA with Sunshine Coast Regional Council. The project would not have occurred or succeeded without the landholder’s dedication to both rainforest conservation and the bush regeneration industry in SE Queensland.

Contact: Spencer Shaw, Brush Turkey Enterprises (Natural Area Management), P.O. Box 326, Maleny, QLD Australia 4552; Tel: +61 7 5494 3642 or Mob: 0428 130 769; Email: spencer.shaw@brushturkey.com.au; Web: www.brushturkey.com.au

Rainforest restoration on private land – Wompoo Gorge, Huonbrook, NSW

 Key words: Rainforest restoration, assisted natural regeneration, Lantana control, threatened species conservation

Maree Thompson

Wompoo Gorge is a private property located at Huonbrook in the Byron Shire hinterland, north coast NSW. The property provides a link between Nightcap and Goonengerry National Parks with Coopers Creek running along the eastern boundary. Originally covered by lowland subtropical rainforest with a stand of eucalypt forest extending down from the 100m high escarpment, half of the site was cleared early last century and partially converted to pasture and banana plantations. At the commencement of the project, the area contained various stages of rainforest regeneration and dense infestations of Lantana (Lantana camara). Twenty-seven threatened species (10 threatened flora species and 17 vulnerable animal species) have been recorded at Wompoo Gorge. The site has exceptional restoration potential and overall conservation significance.

Lantana infestation before works

An ongoing ecological restoration project is being implemented at the property, based on the recommendations of the Wompoo Gorge (South) Restoration Action Plan. In the three years to date, dense areas of Lantana in the area originally cleared have been controlled by mechanical means. A 4-wheel drive tractor was used to drive over and flatten Lantana over 2ha, returning a few weeks later to slash the Lantana. This method (first developed by Ralph Woodford at Rocky Creek Dam) resulted in the death of the majortiy of Lantana treated. Care was taken to aviod any existing regrowth of rainforest species near edges and regrowth patches.

Bush regeneration works have now been extended over an additional 14ha. A range of weed control techniques (including overspray and use of a splatter gun) have been used in the denser areas of Lantana not accessable by tractor. Hand weeding with brush hooks and loppers and cut/scrape and paint of Lantana is being undertaken in the more lightly invested native vegetation. Fruits from native plants on site have been collected and spread through out regeneration areas, adding to seed in the soil bank and that which is naturally distributed.

Tractor clearing of Lantana

A monitoring program was established on site prior to the commencement of works. This included eight monitoring transects. Structural and floristic information was collated and photos taken prior to the commencement of works and then at the end of the first year. Data were entered into MERV (Monitoring and Evalution of the Restoration of Vegetation) database and used to produce reports.

From Lantana to bare ground in Year 1

Results. The previously dense Lantana areas have converted from weed to strongly regenerating rainforest by means of natural regeneration occurring over the 3 years since treatment. The areas first treated in Year 1, in particular the area where a tractor was used to control Lantana, have had impressive growth of native species, now up to a height of over 5 metres. Common regrowth species include White Cedar (Melia azederach), Trema (Trema tomentosa), Red Cedar (Toona ciliata), Tamarind, Sandpaper Fig (Ficus coronata), Bangalow Palm (Achontophoenix cunninghamiana), Brown Kurrajong (Commersonia bartramia), Stinging Tree (Dendrocnide excelsa), Pencil Cedar (Polyscias murrayi), Celerywood (Polyscias elegans), Blue Quandong (Elaeocarpus grandis), Black Bean (Castanospermum australe) and Sally Wattle (Acacia sp.). A strong mix of later phase rainforest species are also germinating. Groundcovers include Soft Braken Fern (Culcita dubia), Cunjevoi Lily (Alocasia brisbanensis), Juncus spp., Cyperus spp. and a range of basket grasses (including Oplismenus spp. and Ottochloa gracillima).

Regenerating natives at the end of Year 2. By the end of Year 3 it was difficult to get a view above the regenerating trees to take overview photos.

Lessons learned. As with all projects, follow-up weed control is essential to ensure that native species come to dominate the site in the long term. The project has recently gained funds to continue the works for a further 3 years. This will allow the project to to continue works into nearby areas where it is known that significant and sustainable environmental outcomes can be achieved on a cost effective basis.

Funding. The project is funding by a 3 year NSW Environmental Trust project with addtional support from the 2010 DECCW Great Eastern Ranges Initiative-Connectivity Conservation Incentives; the Northern Rivers CMA Invasive Species Weeds of National Significance program, and the EnviTE Jobs Fund and Green Jobs Corps teams. Further funding has been gained through the Raymond Borland Bequest Grants program and the Big Scrub Rainforest Landcare Group’s Caring for Our Country project.

Contact: Maree Thompson, EnviTE Inc, 56 Carrington Street (P.O.Box 1124), Lismore NSW 2480; Tel: +61 2 6621 9588, Email: mareet@envite.org.au

Evans River catchment to coasts corridor – Northern Rivers CMA

Key words: Riparian restoration, weed control, landholder engagement, community training, Erythrina x sykesii

Maree Thompson

The project. A three-year bush regeneration and weed control program was conducted (from June 2009 to March 2012) along nearly 15km of Evans River in north coast NSW. Carried out byEnviTE Environment, the works were designed to meet priority targets of the Northern Rivers Catchment Action plan. A range of weeds degrading vegetation communities were controlled along 61 ha of native vegetation (20 ha of wetland, 31 ha riparian and 10 h of upland native vegetation). This particularly involved the control of Coral Tree (Erythrina x sykesii).

Evans River catchment to coasts corridor drill injecting Coral Trees. Photo: Maree Thompson

Eight of the ten land managers along the river were private landholders, with one parcel of land being part of the NSW National Parks and Wildlife Service (NPWS) estate. Private landholders were engaged in the project through Landholder Management Agreement commitments and worked alongside professional bush regenerators, gaining skills and knowledge in weed control techniques and bush regeneration strategies. They saw positive changes in riparian vegetation as a result of the works and through this have increased their understanding and support of environment restoration efforts.

In the case of the NSW NPWS estate, significant areas of primary weed control were undertaken in the last two years of the project. This included control of major infestations of Ochna, a difficult weed requiring further follow up in this area to ensure sustainable environmental outcomes.

Live Coral Tree, Evans River September 2010

As well as on-ground works, the project involved a workshop held in Evans Head with attendees learning how to effectively kill Coral Trees. Project promotion through local media and landcare networks, as well as at the local Evans Head markets, helped to raise awareness in the local community Wider community participation included employment of a member of the Bandjalang people, who are traditional owners of the area.

Its outcomes. Contribution to targets of the NR Catchment Action Plan has far exceeded contract requirements. The Coral Tree infestation in the Evans River Catchment has been reduced to minimal levels.

As future reinfestation will occur due to spread of seed, particularly in floods, from the Richmond catchment – on-going, low level, maintenance is required to gain greatest benefits from the investment to date. 

Poisoned Coral Tree

Lessons learned. This project ran over three years, which to date has been uncommon for projects funded by Northern Rivers Catchment Management Authority (CMA). This allowed us to work across the full cycle of seasons over three years, timing treatments for their optimum time for both the species and OHS requirements. This time period proved highly advantageous as it allowed the achievement of sustainable environmental outcomes and reinforced investments for the Evans River Catchment. As a result, we strongly recommend that the duration of restoration projects be three years or more.

Partners and funding.  The project cost $183,230 over the 3 years, over half of which came from the NSW Environmental Trust, about a quarter came from the Northern Rivers CMA and the remainder was contributed mainly by the EnviTE Jobs fund bush regeneration team, with some contributions from NPWS and Richmond Valley Council.  Landholders’ in-kind contributions was valued at an additional $24,790.

Contact: Mike Delaney, Environment Manager, EnviTE Inc, 56 Carrington Street (P.O.Box 1124), Lismore NSW 2480; Tel: +61 2 6621, Mob: 0429 968 070, Email: miked@envite.org.au.

Restoring grassy understorey under Forest Red Gum – Wolston Creek Bushland Reserve, Riverhills, Queensland

Key words: grassy understorey, assisted natural regeneration, Bushcare, Green Panic.

Carole Bristow and Julie Vejle

Wolston Creek Bushland Reserve, is a 47 ha Brisbane City Council (BCC) Bushcare Site at Riverhills, in the south-west outskirts of Brisbane, Queensland. Although only a relatively small area of bushland remains, connectivity is provided by Wolston Creek, its tributaries Sandy and Bullockhead Creeks and the banks of the Brisbane River.

This report is about just one of the plant communities that the Bushcare group (a handful of dedicated locals) is working on: a 1.55 hectare patch of Forest Red Gum (Eucalyptus tereticornis) forest with a grassy understorey (Fig 1).

Fig 1 (a) Understorey of Eucalyptus tereticornis forest at Wolston Creek Bushland Reserve showing a typical swathe of Green Panic before treatment

In mid-2008 when the project commenced, the understorey of the forest was virtually entirely dominated by the exotic grass Green Panic (Megathyrsus maximus var. pubiglumis) due to past clearing and the sowing of pasture grasses for grazing.   However, as there were some native grasses still evident, we wondered whether the site might respond to an assisted natural regeneration approach that has worked on other sites.   Out of curiosity, we cleared Green Panic by hand around a patch of native grasses to give them space to expand. In the process we found that, under the cover of the Green Panic, were struggling native grasses, sedges and wisps of herbs (Fig 2). This then became a test patch, which in turn became a stand of Pitted Bluegrass (Bothriochloa decipiens). The outstanding results energised us to continue.

Fig 2 (a) Much of the site started with very small native germinants which would have been inadvertently killed had the site been sprayed with herbicide. Photo (a) shows how few natives were sometimes initially revealed – in this case Whisker Sedge (Cyperus gracilis), Common Bindweed (Polymeria calycina) and native Glycine sp.

Our treatments. We further cleared the  Green Panic using mattocks. With the weed cover much reduced, rains brought a massive annual weed response.  We considered spot spraying but while the seedbank response was still being discovered, every native plant was important, so the enthusiasm was there to increase hand weeding on an extended basis. To cope with the volume of hand weeding required, removal was aimed mainly at weed individuals that were flowering and/or seeding.  The result was a gradual reduction of weeds and maintenance of a microclimate for germinating natives.

As this site matured and produced such a vigorous response from natives, it became possible to consider other techniques. In January 2009, an adjacent area was slashed by BCC  to prevent Green Panic from seeding into the work area. By May, with good rains, the slashed area had produced a resurgence of natives, so BCC was asked to stop slashing.  We mattocked out the Green Panic crowns, increasing the original work area by 50%.  We realised that slashing several times proved to be a good preparation for primary weeding.  With the Green Panic tops cut and largely decomposed, the pattern of natives and weeds was better revealed and allowed light to trigger germination and growth.

Subsequently, it was found that initial ‘overspraying’ (taking care to spray the standing Green Panic only) produced a similar response.

Results.  Compared with the former near-monoculture of Green Panic, the ground stratum now has abundant native cover comprising: 18 species of native grasses; two sedges; 19 forbs; one shrub; five twiners, and both Forest Red Gum and Maiden’s Wattle (Acacia maidenii) are regenerating.

The area treated within the first year (250 m2) has now been expanded to 1.55 ha.  Of this, 30% can be considered on ‘maintenance’ i.e. stable native cover, requiring minimal visits for the occasional weeds.  A further 65% is undergoing secondary treatment (still requiring regular work to bring it to ‘maintenance’ stage) and about 5% has undergone primary treatment in 2012.

Lessons learned:
1. It is important to try several patches when testing the resilience of a site.  In our case, making a judgement based on one patch of slow response could have caused misinterpretation of the whole site. (Indeed, areas of slow response eventually filled in and helped to create the diverse mosaic of the ground stratum.)
2. Where appropriate, consider slashing/brushcutting/or spraying weedy grasses as preparation for (or initial phase of) primary weeding in areas that have been found to have strong resilience.
3. Try to view the post-primary weed flush (which often appears to be a ‘sea’ of annual weeds)  as part of the recovery process rather than become overwhelmed by it.  The gradual removal of weed still provides protection for germinating natives.
4. Remove weeds before they seed; keep maintenance stage as the goal;  expand the work area in small steps.  (We were lulled into a false sense of success in dry periods, and possibly expanded too quickly.  So we’ve learned to hasten slowly.)
5.  Plant identification is all important. At the start of the project, the main plant we needed to know was Green Panic. In the continual task of sorting weeds from natives, we remind ourselves that ‘If in doubt, don’t pull it out’.  When a plant is found that we don’t know, it is time to take the interesting journey to the Queensland Herbarium.

The main contributing factors to the success so far have been:
The people: curious; persistent; patient; willing to learn from our mistakes; learning to work with nature’s cycles.
The site: has a strong seedbank that was triggered when rains came and its widely spaced trees made it suitable for preparatory slashing.
The motivation:  the reward and excitement of seeing a native plant community build in integrity and diversity.

We anticipate that there is .5 ha yet to treat. Long term success therefore depends upon the continuation of the above factors and continued support from Brisbane City Council.

Acknowledgements.  Brisbane City Council Habitat Brisbane Section, Wolston Creek Bushcare Group, Queensland Herbarium

Contacts:  Wolston Creek Bushcare Group: For more information, email info@wacc.org.au