Category Archives: Western Australia

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

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

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.

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

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.

 

 

Bat recolonisation of restored jarrah forest in south-western Australia

Joanna Burgar

Keywords: Eucalyptus marginata, dry sclerophyll forest, fauna, echolocation, roost sites

The jarrah (Eucalyptus marginata) forest is part of the internationally recognised biodiversity hotspot of south-western Australia. The northern jarrah forest, approximately 700 000 ha, is subject to multiple uses including timber production, bauxite mining, water supply, recreation and conservation. Alcoa of Australia (hereafter Alcoa) clears, mines and restores approximately 600 ha of forest annually. Alcoa aims to restore a self-sustaining jarrah forest ecosystem. Research suggests that the floristic composition of the jarrah forest tends to be restored, but it is unknown whether the restored forest is habitat for the nine species of insectivorous bats that inhabit the region. Bats are generally considered resilient to human-induced disturbances because of their mobility, ability to exploit anthropogenic structures for roosting and their broad diet. This research project aims to determine if jarrah forest restored after bauxite mining provides habitat for bats.

Works undertaken: Bat activity was surveyed at 64 sites, restored forest of increasing age and reference (mature, unmined) forest (Fig 1), using passive echolocation call detectors. Each site was surveyed for eight nights in spring and summer over two consecutive years. During the first year of the survey, invertebrates were also surveyed at a subset of the sites (n = 24) to determine if there was a difference in invertebrate biomass between restored and reference sites. During the second year of the survey two species of bat, Southern Forest Bat (Vespadelus regulus) and Gould’s Long-eared Bat (Nyctophilus gouldi), were radio-tracked to their diurnal roosts to determine roost site preferences.

Results to date: Bat activity was extremely variable both within sites across nights of sampling and by restoration age. Despite this variation, overall bat activity was significantly higher in reference forest than in restored forest in either year of the survey. In restored forest, overall bat activity was relatively similar regardless of forest age. There was no difference in overall invertebrate biomass between restored and reference sites. The two bat species that were radio-tracked were never found roosting in restored forest. Rather, all diurnal roosts were located within the reference forest, largely in mature jarrah trees.

 

Figure 1. Restored jarrah forest of increasing age and reference (unmined) forest: a) 0-4 years post restoration; b) 5-9 years; c) 10-14 years; d) >15 years; and e) reference forest.

Lessons learned: Restored jarrah forest provides some habitat for bats, although bat activity was lower in restored than reference forest. Restored forest may provide foraging opportunities, as invertebrate biomass is similar in restored and unmined forest. However, tree hollows take decades to form, so roosting habitat is limited in the restored forest.

 Acknowledgements: This research was possible thanks to ARC Linkage Project LP0882687 between Murdoch University and Alcoa of Australia Limited.

Contact: Joanna Burgar, PhD Candidate, Murdoch University. J.Burgar@murdoch.edu.au Tel: +61 (0)8 9360 6520 http://www.plants.uwa.edu.au/research/ecosystem_restoration

Integrated predator management on the south coast of Western Australia

Key words: predators, feral cat, adaptive management, natural area management, threatened species

Allan Burbidge

The Western Ground Parrot (‘kyloring’ to Noongar people) may be the ‘canary in the coal mine’ warning of imminent fauna collapse on the south coast of WA. Over the past decade, this species has undergone a dramatic decline, with the population currently estimated at 140 individuals. This is causing alarm bells to ring, as there is concern that a range of other threatened animals on the south coast may be at risk from the same threatening processes – species such as Gilberts Potoroo, Red-tailed Phascogale, Dibbler, Noisy Scrub-bird, Chuditch, Western Bristlebird and Malleefowl. Considerable progress in fire management strategies for these species has been made by WA’s Department of Environment and Conservation (DEC) over the last few decades, and fox baiting under the Department’s Western Shield program has been in place since 1996. Despite these programs, however, the Ground Parrot population decline continued, leading to the hypothesis that control of foxes has resulted in an increase in the feral cat population (i.e. mesopredator release), with a corresponding increase in predation on native fauna.

Releasing a collared cat (Photo: Emma Adams/WA DEC)

Field trials of Eradicat® baits have been completed under a research permit in Fitzgerald River National Park. Half of the collared cats were killed by these baits, and bait uptake by non-target species was minimal. In 2011 this trial has been extended to include Cape Arid National Park where 19 cats have been fitted with collars, providing direct evidence of bait uptake. Monitoring of predator activity provides additional information on the success of cat baiting. Should this strategy prove effective, the benefits in the wider landscape will be significant.

Feral cat with bandicoot (Photo: WA DEC)

Several clear lessons arise from this work. First, it requires meaningful and ongoing interaction between researchers and managers to carry out robust field-scale adaptive management projects. Second, we have found that institutional barriers such as inappropriate funding timelines can waste the time of project leaders required to continually secure funding and retain skilled staff. Finally, while there is notional support for adaptive management, it is difficult to convince people to support its implementation adequately.

Putting a radio-collar on feral cat (Photo: Emma Adams/WA DEC)

Funding for this project has come from the Department of Environment and Conservation, State NRM, South Coast NRM Inc, Exetel Pty Ltd, Birds Australia and many volunteers. Numerous people have been active in this project including Sarah Comer, Cameron Tiller, Allan Burbidge, Abby Berryman and Deon Utber.

Further reading:
Comer, S., Burbidge, A. H., Tiller, C., Berryman, A., and Utber, D. (2010). Heeding Kyloring’s warning: south coast species under threat. Landscope 26(1), 48-53.

Contact: Sarah Comer (Department of Environment and Conservation, 120 Albany Highway, Albany, Western Australia 6330; tel (08) 9842 4500; email sarah.comer@dec.wa.gov.au) or Allan Burbidge (Department of Environment and Conservation, PO Box 51, Wanneroo, Western Australia 6946; tel (08) 9405 5100; email allan.burbidge@dec.wa.gov.au)

Fire management at Two Peoples Bay – Mt Manypeaks, Western Australia

Key words: environmental management, threatened species, collaboration, communication

Allan Burbidge

Fire management is a major challenge where there are multiple conservation values and potentially conflicting adjacent community values; the challenge is further exacerbated in landscapes involving rough terrain where access for fire management is difficult. All three factors occur in the Two Peoples Bay – Manypeaks area in south-western Australia, which is mostly conservation estate, with some water reserves, and surrounded by private land. In this often steep and rocky landscape, there are threatened vertebrates such as the Noisy Scrub-bird and Gilbert’s Potoroo, threatened plants and short range endemic relictual invertebrates, all with different habitat requirements, and therefore different management requirements. Superimposed on this are community values which involve the surrounding relatively small private holdings, with homes, timber plantations, stock and agricultural infrastructure

Bushfire on Mount Manypeaks (Photo: Ed Hatherley)

Fire management by the State conservation agencies in the area during the 1970s focussed on fire exclusion, as it was believed that this was optimal for the locally endemic and newly rediscovered Noisy Scrub-bird. However, this resulted in dangerous fuel levels, posing a threat to this species and other conservation values. Despite the need to reduce the threat, only minimal use of prescribed fire was able to be applied to manage fuel levels, because of the area’s difficult terrain and the requirements for many species for long interfire intervals.

Water bomber on route to fire (Photo: Sarah Comer)

The problem seemed intractable until local managers, researchers, senior agency managers and policy makers were brought together to debate the options in a focussed meeting. After considerable debate, this group agreed that selected prescription burns in the untracked zones of Mt Manypeaks could be carried out and some patchy ignition could be initiated on the upper slopes by aerial ignition, in a way that minimised negative impacts on populations of threatened species. This in itself was a challenge, as virtually everywhere in the 28 000 ha study area provided habitat for at least one threatened species.

Noisy Scrub-bird (Photo: Alan Danks)

This process is ongoing and adaptive, particularly in the sense that wildfires extent and impact can never be predicted, but some key points have emerged. First, no single group had all the answers or expertise to understand the complex situation, underlining the importance for all practitioners to embrace dynamic and ongoing partnerships. Progress only came with co-ordinated and collaborative commitment from researchers, policy makers and managers. Second, we found that generalised models are inadequate for (complex) individual cases, particularly where there are multiple species of interest, and these species have different management requirements. Third, the old linear model of management was simply not functional; new knowledge and assumptions concerning the dynamic nature of the threatened fauna and flora populations demanded dynamic management, preferably in an adaptive management framework.

Mount Manypeaks after fire (Photo: Sarah Comer)

Major players in this process have come from Nature Conservation Division and Science Division staff within the Department of Environment and Conservation, with species specific input from the South Coast Threatened Birds Recovery Team, Gilbert’s Potoroo Recovery Team and the Albany District Flora Recovery Team.  Strong collaboration with other land managers such as Water Corporation and plantation managers is essential for the successful management of the conservation interface with other land uses.

Further reading:
Comer, S., and Burbidge, A. H. (2006). Manypeaks rising from the ashes. Landscope 22(1), 51-55.

Contact: Sarah Comer (Department of Environment and Conservation, 120 Albany Highway, Albany, Western Australia 6330; tel (08) 9842 4500; email sarah.comer@dec.wa.gov.au ) and Allan Burbidge (Department of Environment and Conservation, PO Box 51, Wanneroo, Western Australia 6946; tel (08) 9405 5100; email allan.burbidge@dec.wa.gov.au)

The Ridgefield Multiple Ecosystem Services Experiment: restoring and sustaining function in degraded ecosystems

Key words: carbon sequestration, invasion resistance, nutrient cycling, novel ecosystems, intervention ecology

Mike Perring

Introduction. Multiple, simultaneous, and rapid environmental changes make sustaining and restoring ecosystem functions an increasingly important but challenging task. The Ridgefield Multiple Ecosystem Services Experiment, being undertaken at the University of Western Australia’s Future Farm in the Western Australian wheat belt, tests the application of current ideas in ecology to ecological restoration, and seeks insights into how management interventions can sustain and restore multiple ecosystem functions in an era of rapid environmental change.

Design. Our experiment tests how different woody plant species mixtures affect provision of ecosystem functions and services, including carbon storage, nutrient cycling, invasion resistance, biodiversity maintenance, and prevention of soil erosion. We also consider potential tradeoffs in the provision of ecosystem functions, how different plant species mixtures may respond to simultaneous environmental changes, and how different plant species assemblages may affect other trophic levels, both above and below ground.

Experimental treatments, across 124 23x11m rip line plots, comprise native tree and shrub species, and span a diversity gradient from bare and single-species to mixtures of eight species. Species belong to four different functional groups based on differing nutrient acquisition strategies and morphologies. Plant assemblage treatments are replicated across former grazing and cropped landscapes.

The Ridgefield experimental site with formerly cropped area to the right and grazed blocks in middle and left (December 2010)

In addition to the role of species composition in determining ecosystem functions and services, we will examine the effect of simultaneous environmental changes (nitrogen deposition and weed invasion) on our chosen functions and services, particularly since the presence of exotics creates potentially novel ecosystem states. Our experiment will allow us to understand more about how combinations of plant species, and their associated traits, can be utilized to intervene and manage ecosystems to ensure capacity for ongoing function and service provision in the Anthropocene. In terms of theory, we are also interested in whether the provision of multiple ecosystem functions requires greater biodiversity than provision of single services, if there are tradeoffs among services as diversity levels increase, and how the traits of included species affect functioning.

York gum only plot (January 2011)

Participants and potential for collaboration. Participants include: Mike Perring, Kris Hulvey, Rachel Standish, Lori Lach, Tim Morald, Rebecca Parsons and Richard Hobbs. The study provides a platform for the investigation of a wide variety of ecologically and socially important questions, and we encourage interested parties to contact us should they wish to collaborate or conduct trials at the site.

Contact: Mike Perring, School of Plant Biology, University of Western Australia; Tel: +61 (0)8 6488 4692; Email: michael.perring@uwa.edu.au

Translocation of the Corrigin Grevillea (Grevillea scapigera), Corrigin, WA

Key words: Critically endangered, genetic diversity, cryostorage, site preparation, species richness

Bob Dixon

Corrigin Grevillea (Grevillea scapigera) is listed as an Endangered plant under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and as Critically Endangered under the Western Australian Wildlife Conservation Act, 1950. Naturally occurring in heathland and low myrtaceae and proteaceae scrub, the species is known from 13 wild populations, mostly in highly degraded narrow road verges. Attempts were made to obtain, for its restoration, farmland adjacent to the largest known roadside population; but these attempts were unsuccessful. Therefore, translocation of the species to three other distal sites was necessary.

All of the translocation sites, each 0.2 hectare, were previously cleared bushland remnants, at various stages of regrowth and degradation. Compaction was a major problem on two sites [e.g. on an old airstrip, weed invasion particularly Capeweed (Arctotheca calendula) and Onion Grass (Romulea rosea) needed to be addressed; as well as grazing by rabbits].

Bullaring site, vegetation skimmed off, ready for planting in winter 2000.

Works undertaken: Site works included scalping off vegetation (on one site) and partial clearing and ripping (at the other sites); followed by rabbit proof fencing, weed control (ongoing) and the installation of trickle irrigation systems. Initial planting was undertaken with tissue cultured plants, 10 clones representing 87% of the known genetic diversity. Through this process, cryostored clones have been retrieved, grown on and successfully translocated on site. Planting numbers varied from year to year, and totaled several thousand over the life of the project.

Bullaring Oct 2003, the perfect result re-sprouting and seedling recruitment of indigenous species retaining biodiversity on site and resisting weed invasion. (Corrigin Grevillea is the white flowered plant visible in the rows closer to the fenceline.)

Results to date: Plant numbers on all sites, at one time over 1800, have dramatically declined since planting ceased, as this species is a short lived disturbance opportunist – and now total about 400.  However, millions of long lived seeds have been contributed to the soil seedbank. Regeneration from the seedbank has occurred on all sites. (See figures 1-3)  Genetic decline was addressed by planting the more under-represented clones. Restoration of other indigenous species, species richness and cover varies from site to site (See Dixon and Krauss 2008).

Site 1, the most degraded site, is where most of the research is carried out including burning, soil cultivation and smoking to stimulate the soil seedbank.

Lessons learned and future directions: This translocation, based on Dr Maurizio Rossetto’s PhD project, was well researched and coupled with sound horticultural practices. As a result, it has proved very successful and thousands of seeds are in long term storage. Fundamental to plant survival has been fencing to prevent predation by rabbits, water reticulation and the use of quality greenstock. Choosing a good quality weed free site is also essential for achieving a sustainable system. Spraying to prevent seed predation by weevils and caterpillars was also found to be critical to successful seed production.
Stakeholders and Funding bodies: Funding NHT, WWF. A joint project with Department of Conservation and Land Management, Corrigin Shire, Kings Park Volunteer Master Gardeners.

Contact: Bob Dixon, Manager Biodiversity and Extensions, Botanic Gardens and Parks Authority, Fraser Ave., West Perth, Western Australia, 6005. Tel +61 (0)8 94803628: Email: bob.dixon@bgpa.wa.gov.au

Reference: Dixon B. and Krauss S. (2008).  Translocation of the Corrigin grevillea in south Western Australia. Pages 229-234 in Soore, P. S.(ed) Global re-introduction perspectives: reintroduction case-studies from around the globe. IUCN/SSC Re-introduction Specialist Group, Abu Dhabi, UAE.