Category Archives: Techniques & methodology

Restoration of Tuart (Eucalyptus gomphocephala) during prescribed burning in southwestern Australia

Posted on 10 April 2013 | Comments Off

Katinka Ruthrof, Leonie Valentine and Kate Brown

Key words:  fire, regeneration, coarse woody debris, ashbed

Regeneration of Tuart (Eucalyptus gomphocephala), in many parts of its fragmented distribution in Western Australia, is nominal. Previous work has shown it has specific regeneration niche requirements, recruiting in ashbeds within canopy gaps. We conducted a field trial to determine whether regeneration could be facilitated by creating coarse woody debris (CWD) piles that would become ashbeds during a low-intensity, prescribed burn.

Regeneration experiment. Paganoni Swamp Bushland, a peri-urban Eucalyptus-Banksia woodland, was due for prescribed burning in 2011. Prior to the burn, twelve canopy gaps within the bushland were chosen to have CWD piles built up in the centre (5mx5m wide, 0.5m height). Six gaps were chosen to have no ashbeds, and so had any naturally occurring CDW removed. Adjacent to each plot (whether ashbed or no ashbed), an extra 5mx5m plot was marked out as a control.

The six gaps without ashbeds, and half of the 12 ashbeds, were broadcast with Tuart seed in plots of 5m x 5m following the prescribed burn.  Approximately 375 seeds/per 25m2 plot (after typical forestry seeding practice) were sown within one month of the prescribed burn.

The temperature of the control burn that moved through the area was measured in the gaps using pyrocrayons. These temperature-sensitive crayons were used to draw lines onto ceramic tiles. Five tiles were placed into each gap, either on the surface in the non-ashbed plots, or beneath the CWD piles, totaling 90 tiles.

Results. The majority of CDW piles burnt during the prescribed burning activities.  These piles burnt at high temperatures (~560Co) compared with the control plots (~70 Co). After six months, the ashbeds, especially those that were seeded, contained a significantly higher number of seedlings (0.7/m2 ± 0.3) than ashbeds without added seed (0.01/m2 ± 0.01) or control plots (0.0-0.05/m2 ± 0.0-0.05).

Lessons learned. Tuart regeneration can be facilitated at an operational scale as part of prescribed fire activities, through creation of CWD piles and broadcast seeding. However, higher rates of seeding could be used. Raking the seeds following broadcasting to reduce removal by seed predators may also increase seedling numbers.

Acknowledgements. Thanks go to the  State Centre of Excellence for Climate Change, Woodland and Forest Health, Murdoch University; Western Australian Department of Environment and Conservation; and to Friends of Paganoni Swamp.

Contact: Katinka Ruthrof, Research Associate, Murdoch University, South Street, Murdoch, 6150, Western Australia; Tel: (61-8) 9360 2605; Email: k.ruthrof@murdoch.edu.au

A created coarse woody debris pile within a canopy gap, ready for the prescribed burn

A created coarse woody debris pile within a canopy gap, ready for the prescribed burn

A created ashbed following the prescribed burn

A created ashbed following the prescribed burn

Pyrocrayon markings on - a tile showing the temperature of the prescribed burn

Pyrocrayon markings on – a tile showing the temperature of the prescribed burn

Tuart seedlings recruiting following ashbed creation and broadcast seeding. Note that this is the same ashbed as in Figure 2.

Tuart seedlings recruiting following ashbed creation and broadcast seeding. Note that this is the same ashbed as in Figure 2.

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Posted in Fire Ecology & Management, reconstruction, Restoration & management theory, Sclerophyll communities, Techniques & methodology, Western Australia

Seagrass meadow restoration trial using transplants – Cockburn Sound, Western Australia

Posted on 8 March 2013 | Comments Off

Jennifer Verduin and Elizabeth Sinclair

Keywords: marine restoration, seagrass, Posidonia australis, transplant, genetic diversity, microsatellite DNA, provenance

Cockburn Sound is a natural embayment approximately 16 km long and 7 km wide, to the west of the southern end of the Perth metropolitan area. Its seagrass meadows have been reduced in area by 77% since 1967, largely due to the effects of eutrophication, industrial development and sand mining. To answer a range of questions relevant to seagrass restoration, we (i) carried out a transplant trial, (ii) monitored the impact and recovery of the donor site, and (iii) retrospectively assessed genetic diversity in the transplant site.

Methods. (i) The transplant trial was conducted between 2004 and 2008 in an area totalling 3.2 hectares of bare sand at 2.2–4.0 m depth on Southern Flats, Cockburn Sound. Donor material was sourced from a naturally occurring seagrass meadow on Parmelia Bank, north of Cockburn Sound, approximately 16 km away from the transplant site. Sprigs (15–20 cm length) of a dominant local seagrass, Posidonia australis Hook.f., were harvested from donor material and each sprig tied to a purpose-designed degradable wire staples (30 cm in length) and planted and secured into a bare sandy area at 50 cm shoot spacing by SCUBA divers (Figure 1). Sprig survival was periodically monitored in 10 m x 10 m representative sub-plots (15–20 plots per hectare).

(ii) For the meadow recovery study, several plug (a clump of seagrass excavated) extraction configurations were examined in P. australis meadows to monitor shoot growth into plug scars, with metal rings placed into the resulting bare area to monitor shoot growth into it at 3, 10, 13 and 24 months. Rings of 8.3 cm diameter were placed into adjacent undisturbed meadows to act as reference plots. (iii) Shoot material was collected from established plants for microsatellite DNA genotyping from the donor site in 2004, and from the 2007/2008 plantings in the restoration site in January 2012. Genetic sampling from the restoration site was done from mature shoots only, to ensure we were sampling original donor material. DNA was extracted from shoot meristem and genotyped using seven polymorphic microsatellite DNA markers (Sinclair et al. 2009).

Fig1

Figure 1. Transplants in situ, prior to the pegs being covering with sediment (Photo Jennifer Verduin)

Results. (i) The transplants have grown well to fill in gaps and become a healthy, self-sustaining meadow, with first flowering in July 2010, three years after initial transplant in 2007. There has also been considerable natural recruitment in the area through regrowth from matte and new seedlings (Figure 2). (ii) No significant differences in shoot growth between extraction configurations were observed in the donor meadow, and there was an increase in shoot numbers over two years. Based on the number of growing shoots, the predicted recovery time of a meadow is estimated at three years. (iii) Genetic diversity was very high in the restored meadow (clonal diversity R = 0.96), nearly identical to the donor meadow.

Fig2

Figure 2. Aerial view of the restoration site (within yellow markers), with natural recruitment occurring from vegetative regrowth and new seedling recruits (Photo Jennifer Verduin, 2010).

Important considerations for long-term success and monitoring. While several important questions have arisen from this trial, it demonstrated that (i) the transplants achieved a high level of establishment within a few years; (ii) the high genetic diversity in the donor site was captured and retained in the restored meadow; and (iii) surrounding sandy substrate is being colonised by P. australis through regrowth from the matte and natural recruitment from seeds dispersed within and/or from other meadows, (the latter potentially helping to ensure the long-term viability of restored seagrass meadows.)

Partners and Investors: This project was carried out as part of the Seagrass Research and Rehabilitation Program through Oceanica Consulting Pty Ltd, with Industry Partners Cockburn Cement, Department of Commerce (formerly Department of Industry and Resources), WA, Department of Environment and Conservation WA, The University of Western Australia, and the Botanic Gardens and Parks Authority, WA.

Contact: Jennifer Verduin, School of Environmental Science, Murdoch University, Murdoch, WA 6150 Australia Email: J.Verduin@murdoch.edu.au; Elizabeth Sinclair, School of Plant Biology, University of Western Australia, Crawley, WA 6907 Australia Email: elizabeth.sinclair@uwa.edu.au. If you are interested in becoming involved with seagrass rehabilitation through student projects please contact us.

 

 

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Posted in Coastal & marine, Erosion issues & solutions, Genetic issues, reconstruction, Techniques & methodology, Western Australia

Regeneration of Lismore bushland cemetery, north coast NSW.

Posted on 25 November 2012 | Comments Off

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

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Posted in Bush regeneration, Community involvement, Fauna & habitat, Grassland/grassy understorey, New South Wales, Sclerophyll communities, Techniques & methodology, Weed issues & solutions

Restoration after pipeline installation: Pimpama Northern Gold Coast, Queensland.

Posted on 21 June 2012 | Comments Off

Key words: Assisted natural regeneration, topsoil transfer, Wallum Froglet, Regional Ecosystem 12.3.5, pipeline construction.

Mark Bibby

Revegetation works were carried out in 2009-10 to accompany a civil construction project in the northern Gold Coast, Queensland, where a pipeline was being laid through a natural area.

The Regional Ecosystems on site included palustrine wetland (12.3.5), which is habitat for threatened flora species including Phaius australis, P. bernaysii and Schoenus scabripes and the Wallum Froglet (Crinia tinnula).

The goals of the project were to: reinstate vegetation on site after the construction of the pipeline; minimise weed establishment and other maintenance issues; to ensure that no canopy species were replaced over pipes (to avoid root damage to the pipes); and to achieve an optimal  outcome for local biodiversity, including the Wallum Froglet.

Summary of works.  The native vegetation in the path of the pipeline was removed from wet areas with excavators and a crew of regenerators (Figs 1a and 1b). As much as possible of the macrophyte vegetation from the watercourse area was temporarily moved to ‘holding’ trenches, created to allow for a variety of soil moisture levels. (These were lined with plastic and then filled with water).

Some 600 specimens of other plants were removed to a nursery for later replanting. The top 200 mm of topsoil and site litter from the remainder of the site were stripped and stockpiled on site for later replacement.

Fig 1a: Macrophyte holding trenches before replanting.

Fig 1b: Macrophyte holding trenches providing temporary habitat during works.

Following civil works (conducted 8 months after the topsoil stripping) the stored topsoil and litter was replaced (at 30-50mm depth) and plants from the holding trenches replanted in their original positions. Spaces were left between the patches of litter to allow for regeneration from the replaced topsoil. Stumps were replaced on site as habitat.

The 600 nursery-spelled plants were reinstated on site and further planting of tubestock was undertaken, with grasses and sedges translocated from nearby at the site. Seed was collected nearby and spread on site when available. The site was regularly visited by skilled bush regeneration weed control staff members for 12 months.

Results. A high level success was achieved with the translocation of holding trench stock following inundation of the site during summer rains.  After replacement of the topsoil, vegetation and litter, the watercourse and surrounding fringes established well and natural regeneration from the replaced topsoil and germination from the seed dispersed by hand occurred. One year after the completion of works, the site was recovering well (Fig 2a-c) and recent inspections showed that vegetation cover and diversity in the watercourse area is consistent with the pre clearing condition. The terrestrial restoration area is showing good recovery with 15 species (that were not planted on site) observed regenerating. The native to weed ratio is 9:1. Conversely in the area of disturbance (adjacent the project site) without restoration the native to weed ratio is 1:9.

Fig 2a: The watercourse after removal of the vegetation.

Fig 2b: The watercourse upon reinstallation of topsoil and stockpiled plants

Fig 2c: The watercourse after the completion of the contract.

Lessons learned.  The joy of this project was being able to convince the the civil engineers if not also ecologists that a more natural regeneration-style approach could offer preferable outcomes to a standard civil landscaping approach.  Particularly interesting was the need to convince them not to be afraid of some short term ‘mess’ to ensure a good result for a natural area.

Contact: Mark Bibby, Gecko Regen, / 139 Duringan Street,Currumbin, Qld, Australia. Tel:  +61 (7) 5534 6395. Email: admin@geckoregen.org.au ; http://www.geckoregen.org.au/

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Posted in Bush regeneration, Fauna & habitat, Queensland, Riparian & stream ecology, Techniques & methodology, Wetland

Fingal Headland Maritime Themeda Grassland Restoration

Posted on 21 June 2012 | Comments Off

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

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Posted in Bush regeneration, Coastal & marine, Grassland/grassy understorey, New South Wales, Techniques & methodology, Threatened species & communities, Weed issues & solutions

Kirra Dune Revegetation – Queensland.

Posted on 21 June 2012 | Comments Off

Key words.  Dune reconstruction, strand ecosystem,

Mark Bibby

A project was developed in 2009 to remove sand from the intertidal area at Kirra to form a new series of dunes along a 1.5km stretch of beach from Kirra to Bilinga, on the far south coast of Queensland (Fig 1).  While the purpose was to maintain the beach amenity and reinforce a buffer to the shoreline, the reconstruction of the dunes (to an average height of 4 metres and the width v from 25 to 60 metres) also involved reinstating native plant communities along the dunes for stabilisation and the conservation of biodiversity.

Fig 1: Project area – 1.5km stretch of beach from Kirra to Bilinga, Queensland.

Revegetation was conducted in the frontal dune area of the project site and in strategically placed infill planting cells between the frontal dune and the existing vegetation landward edge of the project site (Fig 2). Four locally occurring dune species were selected: Spinifex (Spinifex hirsutus) 65%; Beach Bean (Canavalia rosea) 5%; Goats Foot Convolvulus (Ipomoea pes-caprae) 15%; and Vigna (Vigna marina) 15%.

Fig 2: Revegetation of the dune system using infill planting cells and four locally occurring plant species (April 2011).

For a 12 week period the plants were monitored and watered with a 25,000L capacity off-road truck, with plants replaced as required. The site was then maintained for a period of twelve months post-planting to promote good growth of installed plants, prevent weed incursion, ensure dune stability through increased native vegetation cover and assist natural regeneration of dune species.

The total length of the planting area is 1515m and  approximately 18,000 tubestock were planted out over an area of 18000m2 by a team of 6, who planted a total average of 4500 plants per day.

Results. Planting survival rates varied mainly due to mobile sand and anthropogenic disturbance. Good rainfall over the installation period and for 4 weeks following planting ensured establishment was successful (Fig 3).

Fig 3: Revegetation of dune system 5 months after works (Sept 2011)

At 12 months after the planting on the foredune, Beach Spinifex (Spinifex sericeus) densities are approaching, or in some areas have reached, densities expected for a naturally established frontal dune (Fig 4). Since planting, the nursery-spelled Beach Spinifex have flowered and seeded, however the bulk of the increase in biomass is due to extension of the runners. Beach Spinifex runners have travelled in all directions across the dune (i.e. including up inclines). Small swales of windswept sand can be seen captured in front of Beach Spinifex. Of the three species planted on the frontal dune, Beach Spinifex (overall) has shown the greatest increase in area covered.

Fig 4: Revegetation of dune system 12 months after works (April 2012).

The other two species Vigna (Vigna marina) and Beach Morning Glory (Ipomoea pes-caprae) have also done well, although not increased their biomass as rapidly as the Spinifex. The plants, however, have had a good survival rate and throughout December to April 2012 have seen an increase in their rate of growth. Based on the slower (compared to the Spinifex) growth rates that both the Vigna and the Beach Morning Glory exhibited throughout the establishment period either:

(a) they naturally require more time to establish;

(b) their growth rate throughout winter months is less than Spinifex;

(c) they are more sensitive to wind-blown sand than the Spinifex; or

(d) a combination of factors.

Growth rate, however, was not a specific metric that influenced the decision to include these species in the revegetation species selection; the primary reason for their inclusion was to increase in situ species richness in the mid- to long term. Based on this, their inclusion has been successful. As mentioned previously they are now growing more rapidly and both species have flowered and produced seed.

Runners are beginning to connect the infill planting cells with the frontal dune row plantings. In addition to the three species used in the frontal dune plantings, Beach Bean (Canavalia rosea) was also included. The establishment, growth and survivorship of Beach Bean has been similar to that of Vigna — a period where growth appeared minimal and then more rapid growth throughout summer 2011/2012.

Overall survival rate is approximately 80%, however survival rate of individual plants is probably not the best measure of success for a project of this nature. Percentage cover or biomass is a more appropriate measure. Despite this, whichever measure of success is chosen the project has met and exceeded requirements.

Plant abundance and vegetative cover are very good to excellent. Combined with the species composition (richness) many areas of the frontal dune are indistinguishable from a naturally occurring frontal dune. The plants are reproducing and increasing their abundance; at this point predominantly vegetatively (i.e. ‘runners’) however all species have produced seed and these could reasonably be expected to add to the plant population.

The plants are well established and (in the absence of any extreme natural events or destruction by intent) self-sustaining.

Lessons learned.  Beach Spinifex (Spinifex sericeus) is a rapid colonizer of frontal dunes and was the first of the four planted species to reinforce a buffer for the newly created dunes.

The largest threats against successful establishment are:

  • Anthropogenic disturbance through the planting establishment area. This resulted in breaking the ‘crust’ that forms on the top of semi-stable sand, making the underlying sand more susceptible to erosion.
  • Sandblow that covers or undermines plants in the first few months post planting.

Because the sand was “sterile” (due to it having been reclaimed from the intertidal zone and lacking a seed bank), weed invasion, up to this point, has been minimal. This may suggest that weeds predominantly recolonise natural dunes due to accumulated seeds and other propagules persistent in the sand.

Stakeholders: The Department of Environment and Resource Management (DERM) has been responsible for the project management of the Kirra Beach Restoration Project. The Gold Coast City Council (GCCC) is a key stakeholder and the primary service provider for the works.

Contact: Mark Bibby, Gecko Regen, / 139 Duringan Street,Currumbin, Qld, Australia. Tel:  +61 (7) 5534 6395. Email: admin@geckoregen.org.au ; http://www.geckoregen.org.au/

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Posted in Coastal & marine, Erosion issues & solutions, Queensland, Techniques & methodology

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

Posted on 19 June 2012 | Comments Off

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

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Posted in Bush regeneration, Queensland, Rainforest, Techniques & methodology, Weed issues & solutions

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

Posted on 28 May 2012 | Comments Off

 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

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Posted in Bush regeneration, New South Wales, Rainforest, Techniques & methodology, Weed issues & solutions

Planting for success – using long stem plants

Posted on 6 December 2011 | Comments Off

Key words: restoration, planting, riparian,  revegetation

Leah Andrews

Development of the long-stem planting method in Australia has seen an increase in the survival rates of seedlings of a range of species planted in many different environments.  While research to test the value of the method for a broader number of species is currently ongoing (see Trials and Results below) the technique has now been successfully used on subsets of species in riparian, rainforest, coastal and saline environments.  The advantages of this method are no post-plant watering, increased growth and increased survival rates.

The approach. The long-stem planting method is a way of planting that can result in enhanced survival with minimal post planting care.  Seedlings are grown in pots for 10-18 months so that they develop long woody stems.  These seedlings are then planted with about three quarters of their long woody stem below ground.  Once planted the buried stem develops roots and leaf nodes resulting in the development of a robust root network which gives the seedling a greater chance of survival.  This method challenges two long held horticultural practices: (i) that large plants should not be grown in small containers as they will become root bound and will hinder full growth of the plant; and (ii)stems of seedling should not be planted below the surface of the soil as it subjects them to fungal attack and disease.

Cover of the Long-stem Planting Guide

Trials and results to date: The method was originally pioneered by Bill Hicks in the Hunter Valley to reduce the use of willows in the riparian environment and has now expanded and proved successful in a range of environments and with a variety of plant species. Experimental field trials on the application of the method on particular species have been carried out by researchers at the School of Environmental and Life Sciences, University of Newcastle, and Gosford City Council since 2005 Knowledge of the species that suit this technique is building as more bushcare groups and individuals across Australia continue to trial the technique.

The Environmental Trust funded Gosford City Council and the Australian Plants Society to pull together the current anecdotal and researched information on the use of this technique into a Guide for use by practitioners.  (See full Guide at: www.environment.nsw.gov.au/grants/dissemination.htm#longstem).  This project found that the main benefit within the riparian environment is that the roots of the seedlings are planted deeply in to the river bank making it harder for them to be washed away.  Eucalyptus camaldulensis is one of many species that has show enhanced performance in this environment.  In rainforest environments, the long-stem seedlings will often not grow to the suggested one meter prior to planting,  but  a range of plants such as  Glochidion ferdinandi show increased growth once planted.

In the coastal environment this method has shown promise, possibly due to the potential for  the deep rooting to reduce root competition, provide additional anchoring (therefore reducing the impacts of sand movement), greater access to soil moisture and reduced impact from heat.  Acacia longifolia is one example of a species that has been successfully used in coastal environments.  With regards to the saline environments, again the deep rooting is a major advantage as the plants roots are below the salt encrusted upper soil layer.  A large range of species have been found to successfully grow using the long-stem technique in this environment such as: Eucalyptus botryoides, Eucalyptus tereticornis, Eucalyptus robusta, Melaleuca styphelioides, Melaleuca linarifolia, Melaleuca quinquenervia, Acacia binervia, Acacia saligna, Casuarina glauca and Casuarina cunninghamiana.

Lessons learned and future directions: Plants need to be grown in pots placed in potting racks so that the roots are air pruned if they protrude from the pot. This will allow the roots to spread out in to the surrounding soil when planted.  Soaking the seedlings the night before you intend to plant out the long-stemmed plants assists with their survival. Whilst the long-stem planting technique has been shown to be successful particularly in environments where the surface soil conditions are not favorable for planting, the costs of this technique do need to be considered. Long-stem plants are kept in the nursery for longer than traditional tubestock or direct seeding so there is some increased cost per plant.  However, if balanced against the other advantages in environments where establishing vegetation is more challenging, the additional costs can be minor when offset against increased survival.

Stakeholders and Funding bodies: NSW Government’s Environmental Trust, Australian Plants Society – Central Coast Group, Gosford City Council

Contact: Leah Andrews, Senior Project Officer, Environmental Trust 02 8837 6081

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Posted in New South Wales, Riparian & stream ecology, Techniques & methodology

The use of fauna gates to facilitate the movement of Southern Brown Bandicoots Isoodon obesulus through a feral proof fence at the Royal Botanic Gardens Cranbourne

Posted on 26 October 2011 | Comments Off

Key words: fauna gates, feral proof fence

Bronwyn Merritt

The Southern Brown Bandicoot (SBB) Isoodon obesulus, once common along the coast from Sydney through to Adelaide, has dramatically declined in range and number since European settlement. Listed as an endangered species under the Environment Protection and Biodiversity Conservation Act 1999, SBBs are threatened by habitat loss, isolation, fragmentation, urban infrastructure and predation by introduced predators such as foxes.

The Royal Botanic Gardens Cranbourne (RBGC) is regarded as one of the most secure remnant populations of SBBs in the Melbourne and Western Port region. The persistence and relatively high abundance of the species at the RBGC can be attributed to ongoing integrated feral animal control, feral proof fencing and vegetation management.

The RBGC is 363 hectares, with approximately 250 hectares of remnant vegetation listed as of state conservation significance. The site is bounded by an 8 kilometre ‘floppy top’ feral proof fence that has been an integral part of the fox control program. It has resulted in ongoing reduced fox numbers and the flow-on of significant benefits for the management of SBB. However, the fence also represents a barrier to the movement of native species and this may affect the viability of populations within and outside the RBGC.

It has been observed that smaller SBBs are able to pass thorough the 50mm diamond mesh cyclone wire of the feral proof fence. This activity is probably sufficient to reduce local genetic isolation for the species. However, in places the fence has been reinforced with a second or third layer of wire skirting to reduce rabbit incursions and has, therefore, become less permeable to a range of native fauna.

The RBGC has an ongoing program trialing different methods to make the fence selectively permeable to some animals, whilst limiting the movement of others. Originally, the RBGC developed custom made gates that allowed the movement of Common Wombats (Vombatus ursinus) and Long-necked Tortoises (Chelodina longicollis). More recently, the RBGC has developed and trialed the use of ‘Bandicoot gates’ that have allowed free movement of the endangered SBB through the fenceline.

The custom designed bandicoot gates were installed in the internal Australian Garden fence of RBGC through 2010-2011. The Australian Garden is an 11 hectare display garden of native plants. The aim of the bandicoot gates was to allow the free movement of bandicoots, but exclude rabbits. The gates were made using 90 mm PVC pipe. Different gate versions were trialed and the successful design included a weighted 100mm wide flap and cover to ensure the gate returned to the closed position. The gates were monitored using Reconyx™ infra-red cameras and have shown frequent bandicoot movement, with no evidence of other species use to date.

The ability of the SBBs to learn how to negotiate the gates has ongoing implications for the construction of semi-permeable feral proof fences. It may be possible that these gates could be modified and used by other conservation reserves with feral proof fencing, for the conservation of other endangered small mammals.

For the RBGC, this has implications for allowing the free movement of the SBB into the wider region beyond the boundary of the perimeter fence. Since 2002, the land surrounding the RBGC has been included in the Melbourne Urban Growth Boundary, which means the RBGC is likely to be land-locked by residential development in the near future. The development of these gates, and the implication of allowing increased movement of SBB from the RBGC into proposed biolinks, will have significant implications for the ongoing management and sustainability of this endangered species.

Acknowledgements: Terry Coates, Ollie Sherlock, RBGC Infrastructure branch, Jill Burness, Dave Hunt and Ricardo Simao.

Contact: Bronwyn Merritt, Coordinator Land Management and Infrastructure, Royal Botanic Gardens Cranbourne, 1000 Ballarto Road, Cranbourne, Victoria 3977. Ph (03) 5990 2221. Bronwyn.merritt@rbg.vic.gov.au

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Posted in Fauna & habitat, Techniques & methodology, Threatened species & communities, Victoria