Category Archives: Urban ecosystems

Beyond the 1990s, beyond Iluka – koalas and citizen science – UPDATE of EMR summary

Daniel Lunney, Lisa O’Neill, Alison Matthews, Dionne Coburn and Chris Moon

[Update of EMR summary – Lunney, Daniel, Lisa O’Neill, Alison Matthews and Dionne Coburn ( 2000) “Contribution of community knowledge of vertebrate fauna to management and planning. Ecological Management & Restoration, 1:3, . 175-184. https://onlinelibrary.wiley.com/doi/10.1046/j.1442-8903.2000.00036.x]

Key words: national parks, SEPP 44, adaptive management, social criteria, extinction, wildlife survey, coastal forests.

Figure 1. Interest in local wildlife among residents and visitors to the north coast village of Iluka was growing in the 1990s, providing an opportunity for community involvement in our wildlife survey designed not only to gain information but to raise awareness. (Photo Dan Lunney 1991.)

Introduction. Our EMR feature published in 2000 reported on research that commenced in 1997 when we set out to identify the species and locations of the vertebrate fauna of Iluka peninsula, at the mouth of the Clarence River NSW, Australia. Much of the peninsula had been damaged by post war sand mining and creeping urban growth. We had recognised that there was a growing interest by local communities in conserving biodiversity (Fig 1), as Iluka had residential areas not far from a magnificent Nature Reserve (Iluka NR) and a National Park (Bundjalung NP). We conducted a community-based survey, sent to every household, which used a large, coloured map of the peninsula and a questionnaire asking respondents to mark the locations of the fauna they had seen. As a result of the survey, we concluded that vertebrate fauna does live on private land, that local knowledge is valuable, and that there is both community concern over declining fauna and support for planning, management and long-term fauna research.

Figure 2. Two junior volunteers learning radio-tracking to locate koalas, Iluka Peninsula. (Photo Dan Lunney 1992)

The rise of citizen science. We were not the first to use a community-based survey for wildlife in NSW. A team (Philip Reed and Dan Lunney) in 1986-87 greatly expanded on some skilled, but tentative, efforts to survey Koala (Phascolarctos cinereus) in NSW by the small but effective Fauna Protection Panel. We produced a small questionnaire, which was distributed in 1986, and when we came to analysing the data in 1987, we joined up with CSIRO scientist Paul Walker who had a new tool, GIS, still in its infancy, but which showed great promise. By the time of the Iluka study, GIS was central to our methods.

Over the last 20 years there has been a revolution in the acquisition and application of community knowledge (Figs 2 and 3), a better appreciation of its extent, and limitations, and how to better integrate a greater diversity of disciplines for a more effective planning and management outcome. A Google Scholar search for ‘citizen science’ in July 2019 returned over 2 million results, establishing this phrase in the scientific literature to describe projects that enlist the community for collecting or analyzing scientific data. The rise and success of citizen science undoubtedly stems from the power of the internet and web-based tools that members of the public can use to record species’ locations, providing answers to such questions as: is a species increasing, decreasing or stable? – answers to which increase the capacity for managers and planners to be better targeted in their decisions. Such web-based technology also helps to overcome resource limitations where scale is an important factor. For example, for our 2006 state-wide koala and other wildlife survey we put a major effort into the distribution of the survey, a paper form with a large map. Now, the current 2019 survey is web-based, a procedure we explored in north-west NSW in 2014 where we selected the study area to be 200 by 300 km.

Figure 3. A skilled team climbing a tree to capture a koala for a health check and radio-tracking in a study of the koala population of the Iluka peninsula. (Photo Dan Lunney 1991.)

A further innovation comes from linking sociology to ecology and expanding the term from citizen science to ‘crowd-sourced information’. An example is a study in the four local government areas just north of Iluka, namely Lismore, Byron, Ballina and Tweed. The sociological side, led by Greg Brown, used the threatened koala as a case in point. The study demonstrated a novel, socio-ecological approach for identifying conservation opportunity that spatially connected landscapes with community preferences to prioritize koala recovery strategies at a regional scale. When multiple criteria (ecological, social, and economic) were included in the conservation assessment, we found the social acceptability criterion exerted the greatest influence on spatial conservation priorities. While this is a long way from our 1997 Iluka study, it is in the same lineage and represents two decades of development of what has become a widely accepted approach to regional planning.

Lessons learned and future directions. Looking back at the Iluka story, in one sense, it is a sorry one. When we first started our research on the Iluka peninsula in 1990, there was a visible population of koalas. It dwindled to extinction over the next decade so the locations of koalas in our EMR paper were of recent but fading memories. By defining our study area to a small location, it was possible to identify the cumulative impact of mining, housing, disease, roadkill, dog kill and fire. There have been reports of koalas being back on the peninsula as early as 2002 (Kay Jeffrey, local resident) and there have been subsequent sightings (John Turbill DPIE pers comm August 2019), we presume moving down from such locations as the northern part of Bundjalung National Park

Looking back on our EMR paper, we also see that the Emu (Dromaius novaehollandiae) was one of the most common species recorded by the community on the Iluka peninsula. It has now gone (John Turbill DPIE, pers. comm., August 2019). The coastal Emu population in northern New South Wales is now recognized as being under threat and a citizen science project called ‘Caring for our Coastal Emus’ has been established to collect recent emu sightings from the public using a web-based emu register to pin-point locations on a map. This register is administered by Clarence Valley Council and reflects the shift from the 1990s where the tools and expertise for collecting scientific data for management and planning were beyond the scope of local government. Today, local councils are considerably more engaged in conservation and community education projects.  Indeed, the Clarence Valley Council (2015) has prepared a Comprehensive Koala Plan of Management (CKPoM) for the lower Clarence, which includes Iluka, although it was not adopted beyond council level. The plan recognizes the importance of reducing further clearing and protecting and rehabilitating those areas that remain, and identifies that further studies and monitoring are required to establish the current status of the Iluka koala population.

In the early 1990s, we had prepared a possible plan of management for the koalas of Iluka peninsula but there was no legal incentive to adopt it. Thus, in late 1994, when one of us (DL) was asked by the then NSW Department of Planning and Urban Affairs to help write a SEPP (State Environmental Planning Policy) for koala habitat protection, the potential value of doing so was clear to us. SEPP 44 was written in three days, with a promise to revise it in 1995. SEPP 44 has proved to be valuable, although in recent years, the process of preparing and submitting CKoPMs from councils to the NSW state government seems to have stalled.

In conclusion, our EMR feature was written at the time of an upward inflection in the study of koalas, of fauna survey using crowd-sourced information.  We are now better equipped to use the new techniques from over three decades of what might be described as adaptive management of the ideas in our original EMR paper. We also press the point that research, exploring new ideas, incorporating new techniques and publishing our findings and thoughts make a crucial contribution to conserving not only koalas, but all our wildlife and natural areas, both in and out of reserves.  Such research is therefore vital to the survival of our wildlife.

Stakeholders and Funding bodies: In addition to the funding bodies in our EMR paper of 2000, support for the research supporting the above comments has been extensive, as reflected in the acknowledgements section of each report.

Contact. Daniel Lunney, Department of Planning, Industry and Environment NSW, (PO Box 1967, Hurstville NSW 2220 and the University of Sydney, NSW 2006. dan.lunney@environment.nsw.gov.au).

Ecological restoration in urban environments in New Zealand – UPDATE of EMR feature

Bruce Clarkson, Catherine Kirby and Kiri Wallace

[Update of EMR feature  – Clarkson, B.D. & Kirby, C.L. (2016) Ecological restoration in urban environments in New Zealand. Ecological Management & Restoration, 17:3, 180-190.  https://onlinelibrary.wiley.com/doi/10.1111/emr.12229]

Key words: urban ecology; restoration; indigenous biodiversity; New Zealand

Figure 1. Kauri dieback disease is affecting individual trees (left). [Photo Nick Waipara]

Introduction. Our 2016 EMR feature reviewed the state of research and practice of ecological restoration in urban environments in New Zealand. We concluded that urban restoration can influence and support regional and national biodiversity goals. We also observed that research effort was light, lacking interdisciplinary breadth and may not be sufficiently connected to restoration practice to ensure long-term success of many projects.

While it is only three years since that review was published, urban ecological restoration continues to grow and evolve, and the policy setting and political context have changed significantly. New threats and opportunities have emerged. The spread of a dieback disease and the more recent arrival of myrtle rust, rapid uptake of Predator Free 2050, emergence of the One Billion Trees programme, a surge in housing and subdivision development, and a potentially more supportive policy framework are all major factors.

Threats and opportunities. Kauri dieback disease is severely affecting urban kauri forests and individual Kauri (Agathis australis) trees in Auckland and other northern North Island urban centres (Fig. 1). Large forest areas adjoining Auckland, including most notably the Waitākere Range and large parts of the Hunua Range, are now closed to the public, preventing access to popular recreational areas. The dieback is caused by a fungus-like pathogen Phytophtora agathicida that is spread through soil movement. The disease may have arrived from overseas although this is uncertain. There is no known cure but research efforts are underway to find a large-scale treatment option.

Myrtle rust (Austropuccinia psidii) was first found on mainland New Zealand in May of 2017, probably arriving by wind from Australia. Myrtle rust threatens many iconic New Zealand plant species in the family Myrtaceae including Pōhutukawa (Metrosideros excelsa), Mānuka (Leptospermum scoparium), Rātā (Metrosideros robusta), Kānuka (Kunzea spp.), Waiwaka (Syzygium maire) or Swamp maire, and Ramarama (Lophomyrtus bullata). These species are all used to a greater or lesser extent in restoration planting or as specimen trees or shrubs in urban centres, depending on amenity or ecological context. Mānuka is widely used as a pioneer or nurse crop for native forest restoration and is critical to the economically important mānuka honey industry. Waiwaka is a feature of many swamp forest gully restoration projects in Hamilton and this would be a significant setback if they were badly affected. The impact of myrtle rust is still not clear but experience from Australia suggests it may take several years before it reaches population levels sufficient to cause significant damage.

Figure 2. With rapid housing developments in New Zealand, it is important that urban restoration projects are well-planned and efficiently carried out to provide residents with greenspaces to benefit their cultural, health and wellbeing practices. [Photo Catherine Kirby]

In response to a range of housing issues characterised by many as a New Zealand housing crisis, the previous and current government has embarked on several major initiatives to increase the housing stock. A $1B Housing Infrastructure Fund (HIF) was established in October 2016 with provision for interest free loans to local government to enable opening up of new large areas of housing. Many urban centres including Auckland, Tauranga, Hamilton and Queenstown made early applications to the fund. Hamilton City Council was successful in obtaining $290.4 M support for a new greenfield subdivision in Peacocke on the southern edge of the city. This subdivision is intended to enable development of some 3700 houses over the next 10 years and 8100 in 30 years. Approximately 720 ha of peri-urban pastoral agricultural land would eventually be developed (See summary). Coupled with this, and already in progress, is the construction of the Southern Links state highway and local arterial road network. The first proposed subdivision Amberfield covers 105 ha and consent hearings are currently in progress. The environmental impacts of the proposal and how they might be mitigated are being contested. In brief, survival of a small population of the critically endangered Long-tailed Bat (Chalinolobos turberculatus) is the main environmental focus but other aspects including the extent of greenspace and ecological restoration required for ecological compensation are being considered (Figs. 2, 3). With strong political pressure to solve the housing crisis in Hamilton and in other urban centres, making adequate provision for greenspace, especially urban forest, and preventing environmental degradation and indigenous biodiversity decline will be a major challenge.

Figure 3. Aerial photo of Waiwhakareke Natural Heritage Park (65 ha), an award-winning and ongoing ecological restoration project situated on the edge of urban Hamilton. [Photo Dave Norris]

The Predator Free 2050 (PF2050) programme which gained government (National) approval in 2015, aims to eradicate Stoat (Mustela erminea), Ship Rat (Rattus rattus), Norway Rat (Rattus norvegicus) and Possum (Trichosurus vulpecula) from the whole of New Zealand by 2050 (Department of Conservation 2018). PF2050 is now gaining significant traction in urban environments (Figs. 4, 5) with many urban centres having good numbers of community-led projects underway (See PFNZ National Trust map). Crofton Downs in Wellington was New Zealand’s first predator-free community project. Led by Kelvin Hastie this project has effectively reduced predator numbers to the point that some sensitive native birds e.g. Kākā (Nestor meridionalis), have begun to nest in this suburb after an absence of more than 100 years (See RNZ report). Also in Wellington, the Miramar Peninsula (Te Motu Kairangi) has become a focus, because of its advantageous geography, with a goal to make the area predator free by 2019. Possums had already been exterminated in 2006 (www.temotukairangi.co.nz).

Figure 4. John Innes (Wildlife Ecologist, Manaaki Whenua Landcare Research) demonstrating trapping success. Removing pest mammals reduces predation, and also frees up the habitat and resources for our native fauna and flora to flourish. [Photo Neil Fitzgerald]

The One Billion Trees (1BT) programme was initiated by the new coalition government (Labour, NZ First, Greens) in 2017 with $238M released in 2018 for planting of both exotic and native trees across mixed land use types. It is not clear yet whether urban forest projects have received funding support but the guidelines suggest there is no reason why restoration of native forest in urban settings would not be eligible. While the emphasis is on exotic tree plantations, native species and long-term forest protection are increasingly being considered as viable options by the newly established government forestry agency Te Uru Rākau.

The policy setting for ecological restoration in urban environments is potentially becoming more favourable with the draft National Policy Statement on Indigenous Biodiversity (NPSIB) currently in review and the New Zealand Biodiversity Strategy under revision (See terms of reference). The draft NPSIB emphasises restoration of indigenous habitat in biodiversity depleted environments. Specifically, Policy 19: Restoring indigenous biodiversity depleted environments, recommends a target for indigenous land cover, which in urban areas and peri-urban areas must be at least 10 per cent. The revision of the New Zealand Biodiversity Strategy seems likely to give more emphasis to landscape scale restoration including urban environments.

Figure 5. New Zealand native lizards are extremely vulnerable to mammalian predation (e.g. mice, hedgehogs, ferrets, cats) as well as habitat destruction (e.g. new urban developments). [Photo Tony Wills]

Research update. Using the same targeted Google Scholar search method as reported in the EMR feature we have found 18 new peer reviewed papers published between 2015 and July 2019 (see updated bibliography) that are strongly focused on restoration in New Zealand urban environments. The single paper noted for 2015 was missed in our previous search. Again, we have not included books, book chapters or grey literature. This compares very favourably with the total 27 papers listed in our 2016 review of which more than half dated from 2009. An increasing publication rate confirms increasing interest and research efforts in aspects of urban ecological restoration. While most of the publications remain in the ecological science realm there are now some informed by other disciplines including engineering, psychology, landscape architecture and health sciences.

Most notably since our 2016 review, a new government-funded (Ministry of Business, Innovation and Employment) research programme, People, Cities and Nature, began in November of 2016. This four-year $823 k per annum research programme ends in October of 2020 unless a funding rebid to be submitted in March 2020 is successful. The programme undertakes multidisciplinary research in nine NZ cities via six inter-related projects: restoration plantings; urban lizards; mammalian predators; Māori restoration values; green-space benefits and cross-sector alliances. While the emphasis was on the ecological science of urban restoration at the outset, the programme has become increasingly involved in understanding the multiple benefits of urban ecological projects including social cohesion and health and recreation benefits. The need to connect restoration research and practice has been met by undertaking multi-agency and community workshops involving researchers and practitioners in five cities to date with a further four scheduled before the programme ends.

Acknowledgements. The People Cities and Nature research programme is funded by the Ministry of Business Innovation and Employment under grant number UOW1601.

Information. Bruce D. Clarkson, Environmental Research Institute, University of Waikato, Hamilton, New Zealand bruce.clarkson@waikato.ac.nz; Catherine L. Kirby, Environmental Research Institute, University of Waikato, Hamilton, New Zealand catherine.kirby@waikato.ac.nz; and Kiri J. Wallace, Environmental Research Institute, University of Waikato, Hamilton, New Zealand kiri.wallace@waikato.ac.nz.

Eastern Suburbs Banksia Scrub: is fire the key to restoration? – UPDATE to EMR SUMMARY

Geoff Lambert, and Judy Lambert

[Update to EMR summary  – Geoff Lambert and Judy Lambert (2015) Progress with restoration and management of Eastern Suburbs Banksia Scrub on North Head, Sydney.  Ecological Management & Restoration, 16:2, 95-199. https://onlinelibrary.wiley.com/doi/10.1111/emr.12160]

Key Words. Banksia Scrub, North Head, Critically Endangered Ecological Community, Diversity.

Fig 1. Images of the same location over time, taken from “walk-through” photographic surveys (top to bottom) pre-fire, immediate post-fire and 5-years post-fire. (Photos Geoff Lambert)

Introduction. In the original feature, we reported on a number of projects related to the fire ecology of Eastern Suburbs Banksia Scrub (ESBS), also known as Coastal Sand Mantle Heath (S_HL03), located in conserved areas on North Head, Sydney Australia. Following a Hazard Reduction burn in September 2012, we examined changes in species numbers and diversity and compared these measures with control areas which had been thinned. We fenced one-third of the survey quadrats to test the effects of rabbit herbivory. There had been no fire in this area since 1951.

Twelve months after treatment, burned ESBS had more native plants, greater plant cover, more native species, greater species diversity and fewer weeds than did thinned ESBS (Fig 1). Areas that had been fenced after fire had “superior” attributes to unfenced areas. The results suggested that fire could be used to rejuvenate this heath and that this method produced superior results to thinning, but with a different species mix. Results of either method would be inferior were attempts not made to control predation by rabbits (See 2015 report).

Further works undertaken. In 2015 and 2017 we repeated the surveys, including photographic surveys on the same quadrats. Further Hazard Reduction burns were conducted, which provided an opportunity to repeat the studies reported in the 2015 feature. The study design of the burns was broadly similar to the earlier study, but rabbits were excluded by fencing four large “exclosures” over half the burn site. The pre-fire botanical survey was carried out in 2014, with logistical difficulties delaying the burn until late May 2018. Drought and other factors saw a post-fire survey delayed until October 2019. Photographic surveys of the quadrats have been completed.

Seven cm-resolution, six-weekly, aerial photography of North Head is regularly flown by Nearmap© (Fig 2). We use this photography to monitor the whole of the headland and, in particular, the various burn areas. In order to extrapolate from our quadrat-based sampling (usually 1% of a burn area), the University of Sydney flew 5mm-resolution UAV-based surveys on our behalf, on one of the 2012 burn areas and on the 2018 burn area in November 2017 (Fig 3) .

Apart from the fire studies, the general program of vegetation propagation and management has been continued by the Sydney Harbour Federation Trust and the North Head Sanctuary Foundation. The Australian Wildlife Conservancy has also undertaken a “whole of headland”, quadrat-based vegetation survey as the first stage of its “Ecological Health” rolling program for its sites.

Fig 2. Nearmap© site images (top to bottom) pre-fire, immediate post-fire and 7-years post-fire. (Photos Nearmap)

Further results. The original results suggested that fire could be used advantageously to rejuvenate ESBS and produced superior results to thinning. While subsequent photographic monitoring shows distinct vegetation change (Figs 1 and 2), on-ground monitoring showed that by five years after the fire we could no longer say this with any optimism. In summary:

  • In the immediate fire aftermath, there was vigorous growth of many species
  • Over the ensuing 5 years, plants began to compete for space, with many dropping out
  • Species diversity was high following the fire but then dropped below pre-fire levels
  • Some plants (e.g. Lepidosperma and Persoonia spp.) came to dominate via vegetative spread
  • The reed, Chordifex dimorphus has almost disappeared
  • Tea-trees (Leptospermum spp.) are gradually making a comeback
  • Between 2015 and 2017, ESBS species numbers were outpaced by non-ESBS species, but held their own in terms of ground cover.

The total disappearance of Chordifex (formerly an abundant species on North Head and prominent in the landscape) from fully-burned quadrats was not something that we could have predicted. This species is not in the Fire Response database, although some Restio spp. are known to be killed by fire. This contributes greatly to the visual changes in the landscape. The great proliferation of Lance Leaf Geebung (Persoonia lanceolata) has also changed the landscape amenity (Fig 1, bottom).

To summarise, the 2012 burn has not yet restored ESBS, but has produced a species mix which may or may not recover to a more typical ESBS assemblage with ongoing management over time. Given that the area had not been burned for 60 years, it may be decades before complete restoration.

Our further studies on the use of clearing and thinning on North Head as an alternative to fire (“Asset Protection Zone Programme”), indicates that thinning and planting can produce a vegetation community acceptable for asset protection fire management and potentially nearly as rich as unmanaged post-fire communities (Fig 4). It is necessary to actively manage these sites by removing fire-prone species every two years. In addition, a trial has been started to test whether total trimming of all except protected species to nearly ground level in an APZ, is an option for longer-term management.

Fig 3. “Thinning Experiment” fenced quadrat #3 in July 2019. The quadrat was created in 2013 by removing Coastal Teatree (Leptospermum laevigatum) and Tree Broom Heath (Monotoca elliptica). The experimental design is a test of raking and seeding, with each treatment in the longer rows. All non-endangered species plants were trimmed to 0.25 metres height in mid-2017. (Photo Geoff Lambert)

Lessons learned and future directions. It is too early to say whether we can maintain and/or restore North Head’s ESBS with a single fire. Further fires may be required. A similar conclusion has been drawn by the Centennial Parklands Trust, with its small-scale fire experiments on the York Road site. We need new and better spot- and broad-scale surveys and further burns in other areas on North Head over a longer period. The spring 2019 survey, just completed, offers an opportunity to better assess the notion that fire is beneficial and necessary.

It will be necessary to monitor the effects of future fires on ESBS diversity closely and for much longer than five years. More active management of the post-fire vegetation may be needed, as we have previously discussed in the feature, and as happens at Golf Club sites (also see video) .

The 2012 burn was relatively “cool”. There is some evidence that “hot” burns (such as have been carried out by NSW Fire and Rescue at some Eastern Suburbs golf courses) may produce improved restoration of ESBS. The 2018 burn on North Head was planned as a “hot” burn. This was not completely achieved, but we may be able to compare “hot” and “cool” burn patches within it.

Fig 4. A 2017 UAV image of quadrat 23 five years after the 2012 burn. The image has been rotated to show the quadrat aligned on the UTM grid. The red square shows the rabbit-proof fences; the black square shows the survey quadrat and the blue squares show the four 1×1 metre vegetation plots. The resolution is approximately 5 mm. (Photo University of Sydney Centre for Field Robotics)

Stakeholders. Sydney Harbour Federation Trust, North Head Sanctuary Foundation. Australian Wildlife Conservancy, NSW National Parks and Wildlife Service, Fire & Rescue NSW.

Funding Bodies. Foundation for National Parks & Wildlife [Grant No. 11.47], Sydney Harbour Federation Trust, Australian Wildlife Conservancy.

Contact Information. Dr G.A.Lambert, Secretary, North Head Sanctuary Foundation, (P.O.Box 896, BALGOWLAH 2093, Tel: +61 02 9949 3521, +61 0437 854 025, Email: G.Lambert@iinet.net.au. Web: https://www.northheadsanctuaryfoundation.org.au/

Ku-ring-gai Flying-fox Reserve Habitat Restoration Project at Gordon, 2000 – 2019 UPDATE of EMR feature

Nancy Pallin

[Update to EMR feature –  Pallin, Nancy (2001) Ku-ring-gai Flying-fox Reserve Habitat restoration project, 15 years on.  Ecological Management & Restoration 1:1, 10-20. https://onlinelibrary.wiley.com/doi/10.1046/j.1442-8903.2000.00003.x]

Key words:         bush regeneration, community engagement, wallaby browsing, heat events, climate change

Figure 1. Habitat restoration areas at Ku-ring-gai Flying-fox Reserve within the urban area of Gordon, showing areas treated during the various phases of the project. Post-2000 works included follow up in all zones, the new acquisition area, the pile burn site, the ecological hot burn site and sites where vines have been targeted. (Map provided by Ku-ring-gai Council.)

Introduction. The aim of this habitat restoration project remains to provide self-perpetuating indigenous roosting habitat for Grey-headed Flying-fox (Pteropus poliocephalus) located at Ku-ring-gai Flying-fox Reserve in Gordon, NSW Australia (Fig 1).  The secondary aim was to retain the diversity of fauna and flora within the Flying-fox Reserve managed by Ku-ring-gai Council. Prior to works, weed vines and the activity of flying-foxes in the trees had damaged the canopy trees while dense weed beneath prevented germination and growth of replacement trees.  Without intervention the forest was unable to recover.  Natural regeneration was assisted by works carried out by Bushcare volunteers and Council’s contract bush regeneration team.  The work involved weed removal, pile burns and planting of additional canopy trees including Sydney Bluegum (Eucalyptus saligna), which was expected to cope better with the increased nutrients brought in by flying-foxes.

Figure 2. The changing extent of the Grey-headed Flying-fox camp from the start of the project, including updates since 2000. (Data provided by KBCS and Ku-ring-gai Council)

Significant changes have occurred for flying-foxes and in the Reserve in the last 20 years.

In 2001 Grey-headed Flying-fox was added to the threatened species lists, of both NSW and Commonwealth legislation, in the Vulnerable category.  Monthly monitoring of the number of flying-foxes occupying the Reserve  has continued monthly since 1994 and, along with mapping of the extent of the camp, is recorded on Ku-ring-gai Council’s Geographical Information System. Quarterly population estimates contribute to the National Monitoring Program to estimate the population of Grey-headed Flying-fox.  In terms of results of the monitoring, the trend in the fly-out counts at Gordon shows a slight decline.  Since the extreme weather event in 2010, more camps have formed in the Sydney basin in response to declining food resources.

In 2007, prompted by Ku-ring-gai Bat Conservation Society (KBCS), the size of the Reserve was increased by 4.3 ha by NSW Government acquisition and transfer to Council of privately owned bushland. The Voluntary Conservation Agreement that had previously established over the whole reserve in 1998 was then extended to cover the new area.   These conservation measures have avoided new development projecting into the valley.

From 2009 Grey-headed Flying-fox again shifted their camp northwards into a narrow gully between houses (Fig 2).  This led to human-wildlife conflict over noise and smell especially during the mating season. Council responded by updating the Reserve Management Plan to increase focus on the needs of adjoining residents.  Council removed and trimmed some trees which were very close to houses. In 2018 the NSW Government, through Local Governments, provided grants for home retrofitting such as double glazing, to help residents live more comfortably near flying-fox camps.

Heat stress has caused flying-fox deaths in the Reserve on five days since 2002. Deaths (358) recorded in 2013, almost all were juveniles of that year.  KBCS installed a weather station (Davis Instruments Vantage Pro Plus, connected through a Davis Vantage Connect 3G system) and data loggers to provide continuous recording of temperature and humidity within the camp and along Stoney Creek.  The station updates every 15 minutes and gives accurate information on conditions actually being experienced in the camp by the flying-foxes. The data is publicly available http://sydneybats.org.au/ku-ring-gai-flying-fox-reserve/weather-in-the-reserve/Following advice on the location and area of flying-fox roosting habitat and refuge areas on days of extremely high temperatures (Fig 3.) by specialist biologist Dr Peggy Eby, Council adopted the Ku-ring-gai Flying-fox Reserve 10 Year Management and Roosting Habitat Plan in 2018.  Restoration efforts are now focused on improving habitat along the lower valley slopes to encourage flying-foxes to move away from residential property and to increase their resilience to heat events which are predicted to increase with climate change.

Figure 3. Map showing the general distribution of flying-foxes during heat events, as well as the location of exclosures. (Map provided by Ku-ring-gai Council)

Further works undertaken.  By 2000 native ground covers and shrubs were replacing the weeds that had been removed by the regeneration teams and Bushcare volunteers.  However, from 2004, browsing by the Swamp Wallaby (Wallabia bicolor) was preventing growth of young trees and shrubs.  Bushcare volunteers, supported by KBCS and Council responded by building tree cages made from plastic-mesh and wooden stakes. Reinforcing-steel rods replaced wooden stakes in 2008.   From 2011, the Bushcare volunteers experimented with building wallaby exclosures, to allow patches of shrubs and groundcovers to recover between trees (Figs 3 and 4).  Nineteen wallaby exclosures have been built. These range in size from 7m2 to 225m2 with a total area of 846m2.   Wire fencing panels (Mallee Mesh Sapling Guard 1200 x 1500mm) replaced plastic mesh in 2018.  Silt fence is used on the lower 0.5m to prevent reptiles being trapped and horizontally to deter Brush Turkey (‎Alectura lathami) from digging under the fence.

The wallaby exclosures have also provided an opportunity to improve moisture retention at ground level to help protect the Grey-headed Flying-fox during heat events.  While weed is controlled in the exclosures south of Stoney Creek, those north of the creek retain Trad and privets, consistent with the 10 Year Management and Roosting Habitat Plan.

Madeira Vine (Anredera cordifolia) remained a threat to canopy trees along Stoney Creek for some years after 2000, despite early treatments.  The contract bush regen team employed sInce 2010 targeted 21 Madiera Vine incursions.

A very hot ecological burn was undertaken in 2017 by Council in order to stimulate germination of soil stored seed and regenerate the Plant Community Type (PCT) – Smooth-barked Apple-Turpentine-Blackbutt tall open forest on enriched sandstone slopes and gullies of the Sydney region (PCT 1841).  This area was subsequently fenced. The contract bush regeneration team was also employed for this work to maintain and monitor the regeneration in the eco-burn area (720 hours per year for both the fire and Madiera Vine combined).

Figure 4. Exclusion fence construction method. Pictured are Bushcare volunteers, Jill Green and Pierre Vignal. (Photo N Pallin).

Figure 5. Natural regeneration in 2018 in (unburnt) exclosure S-6 (including germination of Turpentines). (Photo N. Pallin)

Further results to date. The original canopy trees in Phase 1 and Phase 2 (1987 -1997) areas have recovered and canopy gaps are now mostly closed. Circumference at breast height measurements were taken for seven planted Sydney Blue gum trees.  These ranged from 710 to 1410mm with estimated canopy spread from 2 to 6m.  While original Turpentine (Syncarpia glomulifera) had circumferences from 1070 and 2350mm with canopy spread estimated between 5and 8m, those planted or naturally germinated now have circumference measurements between 420 and 980mm with canopy spread estimated from 1.5 to 3m.  A Red Ash (Alphitonia excelsa) which naturally germinated after initial clearing of weeds now has a circumference of 1250mm with a canopy spread of 5m.  Also three Pigeonberry Ash (Elaeocarpus kirtonii) have circumference from 265 to 405mm with small canopies of 1 to 2m as they are under the canopies of large, old Turpentines.  As predicted by Robin Buchanan in 1985 few Blackbutt (Eucalyptus pilularis) juveniles survived while the original large old trees have recovered and the Sydney Bluegum trees have thrived.

In the Phase 3 (1998 – 2000) area south of Stoney Creek the planted Sydney Blue Gum now have circumferences measuring between 368 and 743 (n7) with canopy spread between 2 and 6 m.  in this area the original large trees have girths between 1125 and 1770mm (n7) whereas trees which either germinated naturally or were planted now range from 130 to 678mm (n12).  These measurement samples show that it takes many decades for trees to reach their full size and be able to support a flying-fox camp.

Wallaby exclosures constructed since 2013 south of Stoney Creek contain both planted and regenerated species.  Eight tree species, 11 midstorey species, 27 understorey species and eight vines have naturally regenerated.  Turpentines grew slowly, reaching 1.5m in 4 years.  Blackbutts thrived initially but have since died. In exclosures north of the creek,  weeds including Large-leaved Privet,  Ligustrum lucidum,  Small-leaved privet,  L. sinense,  Lantana, Lantana camara,  and Trad, Tradescantia fluminensis) have been allow to persist and develop to maximise ground moisture levels for flying-foxes during heat events. Outside the exclosures, as wallabies have grazed and browsed natives, the forest has gradually lost its lower structural layers, a difference very evident in Fig 6.

Figure 6. Visible difference in density and height of ground cover north and south of Stoney creek. (Photo P. Vignal)

Coachwood (Ceratopetalum apetalum) were densely planted in a 3 x 15m exclosure under the canopies of mature Coachwood next to Stoney Creek in 2015. In 4 years they have reached 1.5m.  In this moist site native groundcovers are developing a dense, moist ground cover.

Madiera Vine, the highest-threat weed, is now largely confined to degraded edges of the reserve, where strategic consolidation is being implemented with a view to total eradication.

In the hot burn area, which was both fenced and weeded, recruitment has been outstanding. One 20 x 20m quadrat recorded 58 native species regenerating where previously 16 main weed species and only 6 native species were present above ground. A total of 20 saplings and 43 seedlings of canopy species including Eucalyptus spp., Turpentine and Coachwood were recorded in this quadrat where the treatment involved weed removal, burning and fencing  (S. Brown, Ku-ring-gai Council, July 2019, unpublished data).  Unfortunately, however, the timing and location of the burn did not take into account its impact on the flying-fox camp and there was some damage to existing canopy trees. It will be many years before the canopy trees, which are regenerating, will be strong enough to support flying-foxes.

Monitoring from the weather station and data loggers has shown that close to Stoney Creek on a hot day it is typically 2-3° C cooler, and 5-10% higher in humidity, than in the current camp area (pers. comm. Tim Pearson). During heat events the flying-foxes move to this cooler and moister zone, increasing their chances of survival.

Fauna observed other than flying-foxes includes a pair of Wedge-tail Eagle ( Aquila audax plus their juvenile, a nesting Grey Goshawk (Accipiter novaehollandiae) and a Pacific Baza (Aviceda subcristata).  Powerful Owl (Ninox strenua) individuals continue to use the valley. The presence of raptors and owls indicate that the ecosystem processes appear to be functional. Despite the decline of the shrub layer outside fenced areas, the same range of small bird species (as seen prior to 2000) are still seen including migrants such as Rufous Fantail ( Rhipidura rufifrons) which prefers dense, shady vegetation. The first sighting of a Noisy Pitta (Pitta versicolor) was in 2014.  Long-nosed Bandicoot (Perameles nasuta) individuals appear and disappear, while Swamp Wallaby remains plentiful.

Lessons learned and future directions. Climate change is an increasing threat to Pteropus species. On the advice of Dr Eby, Flying-fox Consultant, Council, KBCS and Bushcare Volunteers agreed to retain all vegetation including weeds such as Large-leaved Privet and Small-leaved Privet, patches of the shrub Ochna (Ochna serrulata) and Trad as a moist ground cover in the camp area and areas used by the flying-foxes during heat events.

Building cheap, lightweight fencing can be effective against wallaby impacts, provided it is regularly inspected and repaired after damage caused by falling branches. This style of fencing has the additional advantage of being removable and reusable.  It has been proposed that, to provide understory vegetation to fuel future burns in parts of the reserve away from the flying-fox camp, further such temporary fencing could be installed.

Ku-ring-gai Council has commenced a  program to install permanent monitoring points to annually record changes in the vegetation, consistent with the state-based  Biodiversity Assessment Method.

Stakeholders and Funding bodies. Members of KBCS make donations, volunteer for monthly flyout counts, Bushcare and present educational events with live flying-foxes. KBCS hosts the website www.sydneybats.org.au. Ku-ring-gai Council which is responsible for the Reserve has been active in improving management to benefit both residents and flying-foxes.  Ku-ring-gai Environmental Levy Grants to KBCS have contributed substantially to purchase of fencing materials and the weather station. http://www.kmc.nsw.gov.au/About_Ku-ring-gai/Land_and_surrounds/Local_wildlife/Native_species_profiles/Grey-headed_flying-fox

Thank you to Jacob Sife and Chelsea Hankin at Ku-ring-gai Council for preparing the maps and to volunteer Pierre Vignal for assistance with tree measurements, downloading data loggers and a photo.  Researcher,  Tim Pearson installed the weather station.

Contact information. Nancy Pallin, Management Committee member, Ku-ring-gai Bat Conservation Society Inc.  PO Box 607, Gordon 2072  Tel 61 418748109. Email:  pallinnancy@gmail.com

Eradication of Red Imported Fire Ants in Australia (NRIFAEP Brisbane) – UPDATE to EMR feature

Ross Wylie and Melinda K. McNaught

[Update to EMR feature – Wylie, Ross,  Craig Jennings, Melinda K. McNaught, Jane Oakey, Evan J. Harris (2016) Eradication of two incursions of the Red Imported Fire Ant in Queensland, Australia.  Ecological Management & Restoration, 17:1, 22-32. https://onlinelibrary.wiley.com/doi/10.1111/emr.12197]

Key words. control, invasive ants, Queensland, Solenopsis invicta

Figure 1. Map showing quarantine intercepts, postquarantine detections, and known incursions of Red Imported Fire Ant across Australia. Inset shows the detections and incursions found in Brisbane, Queensland, with Table 1 listing further details for each.

Introduction. The highly invasive Red Imported Fire Ant (Solenopsis invicta Buren) was officially identified in Brisbane, Australia in 2001. A nationally funded eradication programme began in that year and is ongoing. As of 2015, five known incursions – determined by genetically assigning population origin – had been identified across Queensland and New South Wales. In our paper we highlighted that two of these populations have been officially eradicated, and that eradication was still considered feasible for the remaining three.

Further work undertaken. In 2015, modelling showed that the extent of the southeast Queensland infestation had been delimited with a 99.9% level of confidence. Delimitation was achieved in part using newly developed remote sensing technology, which enabled large areas to be rapidly surveyed for Red Imported Fire Ant at affordable cost, and with the assistance of the public in looking for and reporting suspect ants. While this does not guarantee that eradication will ultimately be achieved, or that delimitation failure will not recur sometime in the future, establishing that the invasion has been delimited is an essential prerequisite to the ultimate success of the programme. In 2016, an independent review of the operation and management of the programme and of the tools and strategies it employed concluded that eradication was still technically feasible, cost-beneficial and in the national interest, and that efforts should continue.

In 2017, a national cost-sharing consortium of Federal, State and Territory governments approved funding of $A411 million for a new ten-year programme to finish the job.

Further results to date. We confirm that the infestations at the Port of Gladstone in 2013 and Port Botany in 2014, reported in our 2016 paper as still undergoing eradication treatment, have now officially been declared eradicated (see Table 1). Since then, there have been two additional incursions in southeast Queensland; one at the Brisbane airport in 2015 and another at the Port of Brisbane in 2016 (see Figure 1).

Genetics analysis revealed that both of these detections were new incursions and not related to existing or previous populations in Australia. Although only a few nests were found, the presence of winged reproductives in these nests signalled the possibility that there may have been dispersal by flight prior to discovery. Consequently, a full eradication response was mounted for each incursion. These responses entailed destruction of any detected nests using a contact insecticide and surveillance out to a radius of 5 km to determine the extent of the infestation. Following this, six rounds of treatment over two years were applied to a radius of 500 m around detected nests using baits containing insect growth regulators. At the completion of treatment, two rounds of surveillance, one year apart, were conducted using odour detection dogs with no ants found. Brisbane Airport was declared eradicated in 2019, and declaration is pending for the Port of Brisbane.

Table 1. Chronology of known Red Imported Fire Ant incursions and postquarantine detections in Australia.

Year Detection Country of Origin Location Status
2001 Incursion United States Port of Brisbane, Qld Last nest found Feb 2005; declared eradicated in 2012
2001 Incursion United States Richlands, Brisbane, Qld Eradication in progress; focus of the Ten Year Plan
2004 Postquarantine detection Unknown Port of Brisbane, Qld Destroyed
2006 Incursion Argentina Yarwun, Qld Last nest found Sept 2006; declared eradicated in 2010
2009 Postquarantine detection United States Lytton, Brisbane, Qld Destroyed
2011 Postquarantine detection United States Roma, Qld Destroyed
2013 Incursion United States Port of Gladstone, Qld Last nest found Sept 2014; declared eradicated in 2016
2014 Incursion Argentina Port Botany, Sydney, NSW Last nest found Dec 2014; area freedom declared 2016
2015 Incursion United States Brisbane Airport, Qld Last nest found Sept 2015; declared eradicated in 2019
2016 Incursion Argentina Port of Brisbane, Qld Last nest found May 2016; response complete and declaration of eradication pending.

Lessons learned and future directions. Genetic testing continues to be one of the programme’s most valuable tools in the effort to eradicate Red Imported Fire Ant from Australia and has broader application for other pest eradication programmes. The 2016 Port of Brisbane incursion was shown to have originated from Argentina and was therefore not a remnant from the original 2001 incursion at the Port, which came from the southern United States and whose genotype has not been detected in Australia since 2005. Additionally, genetics showed that it was unrelated to the 2006 incursion at Yarwun or the 2014 incursion at Port Botany, Sydney, both of which came from Argentina. Without such information, the programme would be unable to prove that these incursions were not the result of treatment failure or movement from existing populations in Australia.

As mentioned in our 2016 paper, one of the features characteristic of successful eradication programmes worldwide is that resources must be adequate and there must be commitment to see the project through to completion. In Australia, inadequate resourcing at various times in the programme’s history has threatened the possibility of eradication success. This was most notable in 2006 when, with eradication seemingly on track, a significant downsizing of the programme occurred just prior to the discovery in 2007 of major new infestations outside the known infested area. There was no commensurate increase in resourcing to deal with these finds and for several years the programme adopted a suppression and containment strategy while new tools for detecting and eradicating the pest were developed. A major factor contributing to the funding uncertainty post-2007 was the programme’s failure to delimit properly the extent of the infestation in southeast Queensland. This is a key, albeit basic, lesson for any eradication programme. However, following delimitation in 2015, the national cost-sharing consortium again demonstrated their commitment in 2017 to a programme that had been in operation for 16 years, at a cost of $A347 million, by approving a ten-year, $A411 million extension.

Lastly, the programme’s successes to date have reinforced the generally accepted biosecurity principle that the earlier detection of an exotic organism, the better the chance of eradication. Three of the seven Australian incursions have been at ports of entry with relatively few colonies detected and all were eradicated. The same applies for the three incursions in New Zealand. The larger incursions in central Queensland at Yarwun in 2006 (71 ha) and Port of Gladstone in 2013 (220 ha) were shown by analysis of import timelines and by genetics to be of less than three years’ duration and both were successfully eradicated.

This contrasts with the situation in the United States and China where the ‘war’ against Red Imported Fire Ant has been lost; the ant is believed to have been present in the US for around 15 years before eradication efforts commenced and in China for 10 years. Taiwan’s two incursions were likely present for 3–5 years .before discovery, and in 2017, it claimed eradication of one of these populations at Chiayi. Recent reverse-spread modelling has confirmed that the initial Red Imported Fire Ant incursions in Brisbane occurred in the early 1990s, about 10 years before its official discovery in 2001 (Daniel Spring, 2019, personal communication). This makes the eradication of the 2001 Port of Brisbane infestation (8300 ha) significant, in that it demonstrates that eradication is achievable even for a long-established population.

The programme is now in the second year of the ten-year eradication programme. This entails a staged approach, with eradication treatments commencing in the west of the known infestation area and moving to the east, while at the same time suppressing populations in areas awaiting eradication and containing spread. Several new initiatives are underway, including engaging the public and businesses in self-treatment to assist the eradication effort, and the development of novel treatment technologies.

Stakeholders and funding bodies. Australian Commonwealth, States and Territories

Contact information. Dr Ross Wylie, Science Leader, Biosecurity Queensland (Department of Agriculture and Fisheries, PO Box 426 Browns Plains BC Queensland 4118; Tel: +61 7 33304621 Email: ross.wylie@daf.qld.gov.au). Dr Melinda McNaught, Scientist, Biosecurity Queensland (Department of Agriculture and Fisheries, PO Box 426 Browns Plains BC Queensland 4118; Tel: +61 7 33304622; Email: melinda.mcnaught@daf.qld.gov.au).

Ecological restoration and rehabilitation at Sydney Olympic Park – UPDATE to EMR feature

Jennifer O’Meara and Kerry Darcovich

[Update to EMR feature – O’Meara, Jennifer and Kerry Darcovich (2015) Twelve years on: Ecological restoration and rehabilitation at Sydney Olympic Park, Ecological Management & Restoration, 16:1, 14-28. https://onlinelibrary.wiley.com/doi/10.1111/emr.12150 ]

Keywords: Environmental management, ecological management, threatened species, Habitat management , woodland birds, Green and Golden Bell Frog

Introduction. The 2015 EMR feature described ecological restoration and management works at Sydney Olympic Park, a large urban park containing both remnant and constructed landscapes that underwent significant restoration in preparation for the 2000 Olympic Games. Sydney Olympic Park supports a rich natural environment that includes over 250 native animal species, over 400 native plant species and three endangered ecological communities.  The high ecological values of the Park have resulted in 304 hectares (nearly half of the Park) being zoned under NSW planning legislation for environmental conservation and management.  Key habitats include estuarine and freshwater wetlands, remnant eucalypt forest, saltmarsh meadows and woodland bird habitats.

The Park’s biodiversity is of high conservation significance, and makes a significant contribution to the social and economic values of the Park.  The Park’s natural environments enrich visitor experience, provide a living classroom for environmental education programs, and attract businesses and residents seeking proximity to nature. This project began in 2000 when management transferred from a construction phase after the Sydney Olympic Games to an active management phase and is supported by an extensive long term ecological monitoring program. This update summarises new works and outcomes since 2016.

Further works undertaken. The introduction of new ecological infrastructure for frog habitat targets threatening processes of predation by introduced fish and increasing water availability.  Fish-proof fences have been introduced to wetlands where the predatory fish Gambusia (Gambusia holbrooki) is present in Green and Golden Bell Frog (Litoria aurea) habitat (Fig 1). The fences are placed around ponds or pond clusters and then the pond is dried out and refilled with fish-free water. Constructed of sediment fences 600mm high and embedded in the ground, these fences stretch to a maximum of 200m and have successfully restricted the fish from ponds for more than three years.

Figure 1.  Gambusia fence

In order to reduce the impact of bird predation on tadpoles in key breeding ponds, bird netting secured by wire cables to the ground and supported by hoops has been introduced.  The netting is also used as a response to the sighting of Green and Golden Bell Frog tadpoles in ponds with Sydney Olympic Park staff deploying temporary netting where successful breeding has occurred. Netting is left on the pond until all metamorphs have dispersed from the pond then removed.

Restoration of the water-holding capacity and connectivity of bell frog habitat in the Brickpit and Kronos Hill has been improved with temporary ponds being created with tarps (Fig 2). The aim is twofold – to extend the number of predator-free, drought refuges, important for adult female frogs and metamorphs and to ensure frog corridors maintain connectivity.  More than 10 tarp ponds have been created and have an expected life span of 3-6 years and are very budget friendly. Annual monitoring has shown a remarkable uptake of these ponds by the Green and Golden Bell Frog.

Figure 2.  Tarp pond with netting

Further results to date. The Parks ecological monitoring program is ongoing and now entering the 16th consecutive year for birds, 15th for reptiles and 21 years for the Green and Golden Bell Frog. In 2018-19 the fourth woodland bird survey was completed, a four yearly assessment of the status of woodland birds and vegetation management at Sydney Olympic Park. Fifteen quadrats are surveyed over the spring and autumn seasons to measure bird communities which is then compared to change in vegetation structure. Results show that small birds were strongly, positively correlated with shrub cover, but strongly negatively correlated with tree cover and Noisy Miner (Manorina melanocephala).  Since 2006, Sydney Olympic Park Authority has implemented a habitat modification program aimed at increasing the structural diversity and complexity of key areas of the Park to support woodland birds. The program seeks to build connectivity between key woodland bird habitats with the form of habitat enhancement varying depending on site characteristics. The survey shows that this program is successfully creating suitable habitat for this group of birds.

With the prospect of greater demands by the public to access the Park at all hours (see below), Sydney Olympic Park staff have recently collected baseline light level readings from across the Park to inform decision making.  Data on lux levels and light source was collected from over 160 sites ranging from car parks to mangrove creeks. The main drive of the survey was to collect information on light spill into sensitive habitat areas where darkness is a key ecological feature. The survey led to a review of lighting and identification of where lights could be switched off or timed to decrease light impacts. The findings will also inform future planning for illumination within the Park.

Lessons learned and future directions. Sydney Olympic Park is part of a rapidly densifying area with the 30,000 residents currently located within a 3km radius forecast to increase to approximately 100,000 in ten years. Due to the density of housing, Sydney Olympic Park will be/is already the local park for this community, leading to increasing demand for recreation and access to the Parklands. This presents great opportunities for more people to connect with nature and to incorporate community education and sustainability into Park programs.  A new program known as Park Care has been launched recently and currently rolls out community clean up and revegetation activities.

The flipside of this rapid population increase is increasing risk of disturbance to ecologically sensitive areas which needs to be considered and mitigated carefully as the Park continues to evolve. Ensuring the Park is able to sustainably meet this demand is a focus for management now and into the future. New habitat management plans for ecologically sensitive areas of the Park are being developed to better-guide biodiversity conservation on a precinct level. Ongoing ecological management works, and managing the impacts of human disturbance, will be essential to conserving the ecological values of the Park.

Contact. Jennifer O’Meara, Parklands Ecologist, Sydney Olympic Park Authority, 5 Olympic Boulevard, Sydney Olympic Park 2127 NSW, Australia. Email: Jenny.omeara@sopa.nsw.gov.au

Restoration of Wollongong’s Tom Thumb Lagoon 25 Years On: UPDATE of EMR feature.

 Nicholas Gill

[Update of EMR feature: Gill, Nicholas (2005) Slag, steel and swamp: Perceptions of restoration of an urban coastal saltmarsh. Ecological Management & Restoration, 6:2, 85-93 https://onlinelibrary.wiley.com/doi/10.1111/j.1442-8903.2005.00224.x]

Keywords. coastal wetlands, urban green space, pollution, mangroves, volunteers.

Figure 1. Tom Thumb Lagoon and Greenhouse Park (a) 2008 and (b) 2017. (Source Google Earth)

Introduction. The 2005 feature was drawn from restoration work my students and I became involved in during the early 2000s at Tom Thumb Lagoon (TTL) – an estuarine wetland close to Wollongong’s CBD and adjacent to the Port Kembla industrial area and harbour. By that point Wollongong City Council (WCC), the Bushcare group Friends of Tom Thumb Lagoon (FTTL), industry, Conservation Volunteers Australia (CVA), and many volunteers had been variously working on the site since the early 1990s. After decades of impacts from industrial development, waste disposal, and neglect, this significant restoration effort encompassed removing landfill, reshaping the wetland with channels and shallow benches, revegetation, weeding, and the construction of access and viewing points. By the time we became involved and I wrote the 2005 paper, TTL and the adjacent Greenhouse Park (GHP; Fig 1), were substantially revegetated, aesthetically improved, and the saltmarsh wetlands were seen as ecologically valuable. Participants and stakeholders in the restoration project perceived that substantial progress and improvement had been made. They also perceived, however, that the project suffered from some issues common to such endeavours such as a lack strategic planning and monitoring of ecological outcomes.

Since this time, restoration and other work has continued at TTL and at GHP. The story of what has happened, however, is one of the dynamic and contextual nature of sites such as this. This is true in a biophysical sense of ongoing vegetation change, particularly the spread of Grey Mangrove (Avicenna marina), a native plant previously not occurring on the site but planted for perceived environmental benefits either in the 1990s, or around 2000. This spread (into what was previously saltmarsh and mudflats) arises from past decisions and, while providing benefits, is now potentially causing new problems as well as continuing debates about choices in restoration.  The social context has also been dynamic and influential, as priorities have shifted, as the funding environment has altered, and as the people and groups involved have changed. Finally, Tom Thumb Lagoon remains affected by the legacy of the industrial history of its location. Past waste disposal practices in the absence of regulation have led to pollution problems that have become of greater concern since the early 2000s.

Activities at Tom Thumb Lagoon and Greenhouse Park Today. The wetland area itself is adjacent to a capped waste disposal site that operated from the 1940s until the mid-1970s. This area is known now as Greenhouse Park and is being managed and developed as urban green space with more focus on fostering urban sustainability practices; any restoration work is nested within these foci. TTL and GHP were always associated through overlap between FTTL and GHP staff, and GHP facilities were a base for TTL activities. Today, however, personnel have changed, FTTL no longer exists and its key members are no longer associated with TTL, and TTL/GHP are managed as one site to a greater extent. The result of these factors, and of the achievements already made at TTL, have been a shift towards an emphasis on activities at GHP and a change in TTL activities from active restoration to maintenance. It is now GHP volunteers and associated WCC staff who undertake and oversee work at TTL. At GHP WCC has expended considerable resources in tree planting and expanding a permaculture garden. There is a shelter, outdoor kitchen, and pizza oven for volunteers, WCC and Wollongong firms compost green and food waste, and there are hopes for public, tourism, and event use. Around ten volunteers work at the site weekly. For the GHP staff and volunteers, activities at TTL itself today are largely limited to weeding, picking up litter, and feral animal control. Weeds and litter remain problems, partly due to TTL’s location at the bottom of an urban catchment. In addition, since 2005, frog ponds were installed at the eastern end of TTL for the endangered Green and Golden Bell frog (Litoria aurea), however, it is not clear if the ponds are effective. The non-native Giant Reed (Arundo donax) also remains well established at this end of TTL despite control attempts.

Shifts in support have meant that CVA bowed out of work at TTL/GHP in 2012. Previously their involvement had been via a wetlands program that relied on support from both industry (including Bluescope and NSW Ports, both operating adjacent to TTL) and government programs. Until 2012, in conjunction with WCC, CVA were revegetating the southern slopes of GHP (marked A in Fig. 1) and were removing weeds and litter from the saltmarsh. However, the funding that CVA relied on declined such that CVA was unable to continue at TTL/GHP.

Figure 2.  Eastern end of TTL looking south (a) 2002 and (b) 2019 (Photos Nick Gill)

The Mangroves are Coming. Apart from further revegetation at GHP, the most significant vegetation change at TTL has been the spread of Grey Mangrove. While approval to thin this species has been obtained in the past and some thinning did occur, it has not mitigated their current spread and density. Grey Mangrove spread is clearly seen for the period from 2002 to 2019 in Fig 2 which shows the eastern end of TTL and the southern end of the channel known as Gurungaty Waterway. Aerial photos further reveal changes from 2008-2017 where the largely east-west spread of mangroves along channels in TTL can be seen (marked B in Fig 1). Significant spread can also be seen north-south spread along Gurungaty Waterway over this period (marked C in Fig 1). As the 2005 paper records, not long after Grey Mangrove was planted in the late 20th or early 21st Century, its expansion was  soon causing concern for its consequences for the site’s mudflats, saltmarsh and tidal habitats although it appears to have largely remained confined to the channels and has no doubt generated some environmental benefits. In terms of its consequences on bird habitat, the long observations of local birdwatchers suggest that the expansion of Grey Mangrove has reduced the incidence of waders and shorebirds, particularly Black Winged Stilts (Himantopus himantopus) and also waterfowl and herons. Nonetheless, observers report that Grey  Mangrove colonisation is providing habitat for other birds, such as the Sacred Kingfisher (Todiramphus sanctus), the Nankeen Night-Heron (Nycticorax caledonicus), and the Striated Heron (Butorides striata). Elsewhere across more upland areas of TTL and GHP, the expansion of tree planting across GHP and TTL has seen a shift to birds favouring woodland habitats.

The expansion of Grey Mangrove is also implicated in flood risk, especially for the catchment of Gurungaty Waterway. A 2019 review of the Wollongong City Flood Study, suggests that low elevations and channel infrastructure, combined with sedimentation and flow limitations associated with the now dense mangroves (Fig. 3), have increased the likelihood of flooding in the urban catchment.

Figure 3.  Southern Gurangaty Waterway in (a) 2002 and (b) 2019. Note the steel footbridge on left of each photo. (Photos Nick Gill)

Industrial Legacies. The 2005 paper notes that saltmarsh restoration was an important part of the TTL work and that stakeholders saw the saltmarsh as a significant ecological element of TTL. Since 2004 coastal saltmarsh has been listed as an Endangered Ecological Community in NSW. From 2006, saltmarsh degradation prompted WCC to monitor the saltmarsh and analyse groundwater and soils.  This showed that the degradation was likely associated with ammonia leaching from the tip and causing nitrate pollution, and also with a hydrophilic layer of iron hydroxide in the soil causing waterlogging and contaminant absorption. The possible origins of this layer include past waste disposal practices from metal manufacturing.

These, however, are not the only legacies of past unregulated waste disposal and industrial activity. TTL is now a declared site of ‘significantly contaminated land’ by the NSW EPA. The 2018 declaration notes that site is contaminated by ‘polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons and other mixed contaminants from multiple sources including coal tar and lubricant oils’. At TTL elements of these can be visible as a film on the water surface and are among the substances leaching from GHP. Such substances are carcinogenic and exposure can cause a range of health problems. The presence of these materials in the groundwater has been known since the 1990s but from 2013 WCC began to monitor and map these materials. Monitoring points were installed along the wetlands at base of the old tip. Various remediation options for these contaminants, as well as for the nitrates and iron hydroxide layer, were proposed but action was not taken at this time for various reasons including disruption to the wetland, costs, and uncertainties regarding pollutant interception. As of 2019, the site is subject to a ‘Voluntary Management Proposal’ by WCC which includes the preparation of a remediation action plan by late 2019.

Future Directions. The last fifteen years have seen some aspects of restoration, such as tree planting, proceed and expand. By some measures this is continued progress of the original project. TTL/GHP is now a well-established urban green space with environmental and amenity value. However, concerns from the early 2000s about volunteer succession, the absence of a catchment approach to management, and the need to think more strategically about ecological trade-offs between management options have been realised to some extent. The spread of Grey Mangrove is the clearest example of this. In part, some of this is perhaps inevitable for a site with the history and setting of TTL/GHP; the management context has changed, participants and stakeholders have changed, and difficult legacy issues have assumed greater prominence and cost. Nonetheless, the challenge to manage the site with a clear strategy and goals remains.

Acknowledgements: For assistance with this update, I am indebted to several past and present WCC staff, particularly Mike McKeon. I was also helped by Adam Woods, formerly of CVA, and birdwatchers Penny Potter, Terrill Nordstrom, and David Winterbottom.

Contact. Nicholas Gill, School of Geography and Sustainable Communities Faculty of Social Sciences, University of Wollongong NSW 2522 Australia, Email: ngill@uow.edu.au

Re-establishing cryptogamic crust at The Waterways, Mordialloc

By Damien Cook

Photo 1.  Crytogamic crust consisting of mosses, lichens and liverworts in inter-tussock space in restored grassland at Waterways. These spaces provide recruitment opportunities for herbaceous species such as Wahlenbergia multicaulis and Brachyscome parvula

Introduction:  The Waterways is a unique urban development on the Mordialloc Creek, in Melbourne’s south eastern suburbs, which combines a housing estate with 48 hectares of restored habitat set aside for indigenous fauna and flora in open space, lakes and other wetlands. (See EMR Project summary ‘The Waterways‘.)

The revegetation of 4 hectares of native grassland and 7 hectares of swamp scrub provided the opportunity to trial the re-establishment of non-vascular plant species, as well as the higher plants which are normally the focus of restoration efforts.

Method. A diversity of cryptogams including Thuidiopsis furfurosa, Hypnum cuppressiforme, Triquetrella papillata and some Rosulabryum and lichen species were collected in the field from nearby remnants of native vegetation threatened with imminent destruction by freeway construction and new housing estates. These were placed in a blender and made into a 2 litre, thick slurry and the slurry was then diluted into a 20 litre a firefighting backpack. The diluted slurry was then applied to bare soils in the revegetated areas at the Waterways in August 2002; some areas were left untreated as a control.

Results. It was not until the wet winter of 2016 that it became apparent how successful this technique had been. There are now quite large areas with a good cover of cryptogams, particularly in the restored grassland and swamp scrub areas. There are some cryptogams in the untreated areas, but the species richness and cover are much lower. Cryptogamic crust cover appears to suppress weed germination, reducing the need for herbicide application, yet provides recruitment opportunities for native forbs (see Photos 1-3).

Acknowledgements. Thanks are due to the Haines family who were the developers of “The Waterways”, and in particular Stephen Haines, for involving us in the revegetation of the site and allowing us scope to trial different ecological restoration techniques. 

Contact: Damien Cook (rakali2@outlook.com.au)

Photo 2. Swamp Scrub at Waterways. Note the dense layer of mosses in the understory, particularly Thuidiopsis furfurosa

Photo 3. Fruiting capsules of a species of Bryum in restored native grassland at Waterways

Recovery of indigenous plants and animals in revegetated areas at ‘The Waterways’, Victoria.

Photo 1.  Aerial view of Waterways from the west

By Damien Cook

 Introduction. Waterways is a 48-hectare restoration project located on Mordialloc Creek in Melbourne’s south- eastern suburbs which combines a housing estate with large areas of restored habitat set aside for indigenous fauna and flora in open space, lakes and other wetlands (see Photo 1).

Prior to restoration the land at Waterways was a property used for grazing horses and supported pasture dominated by exotic species such as Reed Fescue (*Festuca arundinacea) and Toowoomba Canary Grass (*Phalaris aquatica). (Note that an Asterix preceding a scientific name denotes that the species is not indigenous to the local area).

The habitats which are being restored at “The Waterways” reflect those that originally occurred in the Carrum Carrum Swamp, a vast wetland complex which, prior to being extensively drained in the 1870s, stretched from Mordialloc to Kananook and as far inland as Keysborough.

Local reference ecosystems were selected to act as a benchmark for what was to be achieved in each restored habitat in terms of species diversity and cover. Habitat Hectare assessments have been used to monitor the quality of restored vegetation (see Appendix 1).

A total of nine Ecological Vegetation Classes (EVCs, the standard unit of vegetation mapping in Victoria) are being re-established across the site across the following habitats

  • Open water, Submerged Aquatic Herbfields and Exposed Mudflats
  • Densely vegetated marshes
  • Swamp Paperbark Shrubland
  • Tussock Grassland
  • Plains Grassy Woodland

Photo 2. This sequence of photographs, taken over a nine-month period at the Waterways, shows vegetation establishment in a constructed wetland from newly constructed and bare of native species on the left to well vegetated with a high cover of indigenous plants and minimal weeds on the right.

Works undertaken. Restoration of the site commenced in October 2000. Extensive weed control and earthworks were carried out prior to the commencement of revegetation works, which involved planting, by 2003, over 2 million local provenance, indigenous plants.  Grassland species were planted out of hikos at a density of 5 to 6 per square meter into areas that had been treated with both knock-down and pre-emergent herbicide. Ongoing management of the site has included ecological burning and follow up weed control. When started the Waterways was the largest and most complex ecological restoration project ever undertaken in Victoria.

Results

Plants

Open water, Submerged Aquatic Herbfields and Exposed Mudflats.  Deep, open water areas cover an area of about 30 hectares of the site. Vegetation growing in this habitat includes submerged herb-fields of Pondweeds (Potamogeton species), Eel Grass (Vallisneria australis) and Stoneworts (Chara and Nitella species), which were planted over summer 2000/01.

Densely vegetated marshes. This habitat occupies about 10 hectares of the site, occurring where water is less than 1.5 meters deep around the fringes of the lakes and as broad bands across the wetlands. Swards of large sedges including Tall Spike-rush (Eleocharis sphacelata), Jointed Twig-sedge (Baumea articulata), Leafy Twig-sedge (Cladium procerum) and River Club-rush (Schoenoplectus tabernaemontani); aquatic herb-fields of Water Ribbons (Cycnogeton procerum), Upright Water-milfoil (Myriophyllum crispatum) and Running Marsh-flower (Ornduffia reniformis); as well as meadows supporting rushes, sedges and amphibious herbs. Localized areas with high salinity (4000 to 12 000 ppm) have been planted with a halophytic (salt tolerant) community including Sea Rush (Juncus krausii), Australian Salt-grass (Distichlis distichophylla), and Shiny Swamp-mat (Selliera radicans). Planting began in the marshes at the Waterways in October 2000 and vegetation established very rapidly in most areas (see Photo 2). This vegetation type provides habitat for the locally vulnerable Woolly Water-lily (Philydrum lanuginosum).

Swamp Paperbark Shrubland covers about 8 hectares, consisting of a 1ha remnant and additional areas that were planted in spring/summer 2001. As this shrubland habitat matures it is forming a dense canopy of species including Swamp Paperbark (Melaleuca ericifolia), Prickly Moses (Acacia verticillata subsp. verticillata), Manuka (Leptospermum scoparium), Woolly Tea-tree (Leptospermum lanigerum), Tree Everlasting (Ozothamnus ferrugineus) and Golden Spray (Viminerea juncea).

Photo 3. Rare plant species that have been established in restored native grasslands at “Waterways” include Grey Billy-buttons (Craspedia canens), Matted Flax-lily (Dianella amoena) and Pale Swamp Everlasting (Coronidium gunnianum).

Tussock Grassland covers about four hectares at the Waterways between two major wetland areas. About a third of this habitat was planted in spring 2001, with the remainder in spring 2002. The dominant plants of this habitat are tussock-forming grasses including wallaby grasses (Rytidosperma species), Kangaroo Grass (Themeda triandra) and Common Tussock Grass (Poa labillardierei var. labillardierei). A diverse array of native wildflowers occurs amongst these grasses. Rare plant species that have been established in this habitat zone include Grey Billy-buttons (Craspedia canens), Matted Flax-lily (Dianella amoena) and Pale Swamp Everlasting (Coronidium gunnianum, see Photo 3).

Plains Grassy Woodland This habitat type occurs in mosaic with Tussock grassland and differs in that it supportsscattered trees and clumps of shrubs. River Red Gum (Eucalyptus camaldulensis subsp. camaldulensis) and Swamp Gum (Eucalyptus ovata var. ovata) have been planted so that they will eventually form an open woodland structure. Other tree and tall shrub species planted in this habitat include Drooping Sheoak (Allocasuarina verticillata), Blackwood (Acacia melanoxylon) and the tree form of Silver Banksia (Banksia marginata), which is now very uncommon in the local area.

Seasonal Wetlands Small seasonal wetlands occur within Tussock Grassland (see Photo 4). Rare plant species that have been established in this habitat zone include Swamp Billy-buttons (Craspedia paludicola), Woolly Water-lily (Philydrum lanuginosum), Grey Spike-rush (Eleocharis macbarronii), Giant River Buttercup (Ranunculus amplus) and the nationally endangered Swamp Everlasting (Xerochrysum palustre).


Photo 4. Seasonal rain-filled wetland at Waterways

 Animals.

The Waterways is home to 19 rare and threatened fauna species including the nationally endangered Australasian Bittern (Botaurus poiciloptilus), Glossy Grass Skink (Pseudemoia rawlinsoni) and Magpie Goose (Anseranas semipalmata). The successful establishment of diverse vegetation has so far attracted 102 species of native birds, and the wetlands on the site are home to seven species of frogs.

Open water areas support large populations of Black Swans (Cygnus atratus), Ducks (Anas species), Eurasian Coots (Fulica atra), Cormorants (Phalacrocorax and Microcarbo species), Australian Pelicans (Pelecanus conspicillatus) and Australasian Darters (Anhinga novaehollandiae) that either feed on fish and invertebrates or the foliage and fruits of water plants.  As water levels recede over summer areas of mudflat are exposed. These flats provide ideal resting areas for water birds as well as feeding habitat for migratory wading birds including the Sharp-tailed Sandpiper (Calidris acuminata), Red-necked Stint (Calidris ruficollis) and Common Greenshank (Tringa nebularia) that fly from their breeding grounds as far away as Alaska and Siberia to spend the summer in Australia and are protected under special treaties between the Governments of countries through which they travel.

Photo 5. Magpie Geese (Anseranas semipalmata) at Waterways

In 2007 a small group of Magpie Geese (Anseranas semipalmata) became regular visitors to The Waterways (see Photo 5). This species was once extremely abundant in the Carrum Carrum Swamp. However, it was driven to extinction in southern Australia in the early 1900s by hunting and habitat destruction. The Magpie Goose seems to be making a recovery in Victoria, with numbers building up from birds captured in the Northern Territory and released in South Australia that are spreading across to areas where the species formerly occurred.

Seasonal wetlands are important breeding areas for frogs including the Banjo Frog (Limnodynastes dumerilii), Striped Marsh Frog (Limnodynastes peroni) and Spotted Grass Frog (Limnodynastes tasmaniensis) and a range of invertebrates that do not occur in the larger, more permanent storm water treatment wetlands such as Shield Shrimp (Lepidurus apus viridus). Birds which utilize these wetlands for feeding include the White-faced Heron (Egretta novaehollandiae) and Latham’s Snipe (Gallinago hardwickii).

Restored grassland provides an ideal hunting ground for several birds of prey, including the Brown Falcon (Falco berigora), Black-shouldered Kite (Elanus axillaris) and Australian Kestrel (Falco cenchroides). It also provides cover and feeding habitat for insect and seed-eating birds such as the Brown Quail (Coturnix ypsilophora). A flock of about 20 Blue-winged Parrots (Neophema chrysostoma) have been regularly seen in this habitat. These parrots are usually quite uncommon in the Melbourne area. Moist grasslands beside the wetland have been colonised by the vulnerable Glossy Grass Skink (Pseudemoia rawlinsoni) (see Photo 6).

Densely vegetated marshes provide habitat for a diversity of small, secretive birds such as Ballion’s Crake (Porzana pusilla), Little Grassbird (Megalurus gramineus) and Australian Reed Warbler (Acrocephalus australis), which find suitable refuges in the cover provided by dense vegetation. Dense thickets of Swamp Paperbark shrublands provide cover and feeding habitat for Ring-tail Possums (Pseudocheris peregrinus) and bushland birds such the Eastern Yellow Robin (Eopsaltria australis), thornbills (Acanthiza species), Superb Fairy-wren (Malurus cyaneus) and Grey Fantail (Rhipidura albiscapa). As the grassy woodlands mature they are providing structural habitat diversity and accommodating woodland birds such as cuckoos (Cacomantis and Chalcites species) and pardalotes (Pardalotus species).

It will take many years for the River Red Gums to reach a majestic size and stature, and to provide tree hollows which are essential for many species of native fauna. A limited number of tree hollows are provided in the dead trees (stags) that were placed in the Waterways wetlands.

Photo 6. The vulnerable Glossy Grass Skink (Pseudemoia rawlinsoni) at Waterways

The Future. The habitats that have been created at the Waterways are about 18 years old, yet they have already attracted a vast array of native fauna. Waterways is now home to 14 rare and threatened plant species and 19 threatened animal species. There is incredible potential for the area to provide vitally important habitat for an even greater diversity of rare plants and animals as these habitats mature.

If the area is to reach its full potential careful management of weeds and pest animals is required. Ongoing monitoring of flora and fauna is also necessary. These are both areas in which the local community is becoming involved.

Acknowledgements. The high standard of restoration achieved on the Waterways project was due to the project being appropriately funded and because it was managed by ecologists experienced in planning and implementing ecological restoration.  The project was partly funded by Melbourne Water, who are now the managers of the site, and partly by a developer, the Haines Family.  This unique relationship and the generosity and willingness to try something innovative by the developer were important factors in the success of the project.

Contact: Damien Cook (rakali2@outlook.com.au)

Appendix 1. Habitat Hectare results for four quadrats at Waterways, 2006

Prescribed burning provides opportunities for site restoration via weed management in the Mount Lofty Ranges, South Australia

Andrew Sheath

Introduction. The purpose of much of the prescribed burning work we do in the Mount Lofty Ranges in South Australia fuel reduction to mitigate the risk of bushfire. But we also do a lot of work, including burning, purely for the purpose of biodiversity conservation. Being so close to Adelaide all of our Parks are highly fragmented and have a strong history of disturbance such as mining and grazing.

Within our team we have a very strong focus on weed control and we do this routinely for all of our burns. There are two reasons we have such a focus on weed management and no longer just go in and burn and walk away. The first is to ensure that the vegetation condition does not deteriorate and the second is to ensure that fuels don’t increase due to woody weeds. In many cases this is leading to improvements in quality of the sites.

Methods. Our burns are done under a prescription which specifies certain weather parameters for which the burn can be carried out safely. Our sites are typically between 5 and 200 hectares, often adjacent to built assets (Fig 1). Mapping both before a burn and 4 years after a burn allows us to monitor progress. We map most of our burns on foot, assessing native vegetation condition, weeds present, their distribution and their cover throughout the proposed burn site. We undertake this with a view to gaining a clear picture of what we’ve got to deal with during the burn and post-burn. Our planning begins 6-18 months prior to a burn to give us plenty of time to carry out works that are often seasonally dependent.

Fig 1: Example of a typical Adelaide Hills conservation area on the urban fringe. Red areas show prescribed burns either completed or in the planning phase.

Fig 1.  Example of a typical Adelaide Hills conservation area on the urban fringe. Red areas show prescribed burns either completed or in the planning phase.

Examples and results to date. In most of our situations pre-burn control greatly increases the efficiency of any post-burn work and overall makes our work easier.

Example 1: Figures 2 and 3, shows a significant reduction in the distribution of Gorse (Ulex europaeus) at an otherwise relatively intact site after the burn, improving the condition of the bush in this area.

Fig 2. Gorse distribution and density pre-burn

Fig 2. Gorse distribution and density pre-burn

Fig 3: Gorse distribution and density 3 years post burn after control work

Fig 3. Gorse distribution and density 3 years post burn after control work

Example 2: Figure 4 shows successful tree heath (Erica arborea) control in an otherwise intact woodland in the Adelaide hills. Six months prior to burning we cut and disturbed the stand of Tree Heath on this site to ensure all the biomass would burn; that we wouldn’t have the adults sitting up high above the flame dropping seed onto burnt ground (which often happens when burning under mild conditions); and, to promote juveniles which would then be burnt and killed during burn. The other benefits of this approach are that it also promotes native germination and makes follow up, post-burn easier.

Fig 4: Erica control site showing before being burnt or cut, after being cut and post burn.

Fig 4: Erica control site showing before being burnt or cut, after being cut and post burn.

Fig 5. Erica post control and pre-burn

Fig 5. Erica post control and pre-burn

Fig 6. Erica post-control and post-burn

Fig 6. Erica post-control and post-burn

Example 3: Figure 5 shows a perched swamp in the Adelaide Hills being thickly invaded by Wonnich (Callystachys lanceolata) from Western Australia. Because of location of the site we were unable to burn the swamp at sufficient intensity to consume the Wonnich. So in this situation we burnt the surrounding area in spring in mild conditions within prescription. We later went back in autumn after we had dropped all of the Wonnich on the ground and we burnt that swamp at a very high intensity and consumed all of the biomass. That promoted mass-germination of the weed. We’re then dealing with one age-class and we can go through and hand weed, spot spray, and re-burn areas to control the germination. Joe Quarmby, Threatened Flora Ecologist, was the mastermind behind this burn and continues to drive follow up control work at the site.

Fig 7. Swamp burnt in drier conditions during autumn.

Fig 7. Swamp burnt in drier conditions during autumn (after surrounding area burnt in more mild conditions in an earlier season).

Follow up control work in swamp.

Fig. 8. Follow up control work in swamp.

Lessons learned. Burning can be a very useful tool for weed management and although no site is ever the same we have been able to use a variety of techniques for certain weeds which greatly increase our efficiency. The key point however is that weed control should be and is routine and needs to be thought about pre-burn.

Acknowledgements. Thanks is extended to Joe Quarmby, Threatened Flora Ecologist.

Contact: Andrew Sheath, Department of Environment Water and Natural Resources – South Australia. Tel: +61 0457 512 032, Email: Andrew.Sheath@sa.gov.au

[This project summary is a precis of a talk presented to the Nature Conservation Council of NSW’s 10th Biennial Bushfire Conference, ‘Fire and Restoration: Working with Fire for Healthy Lands’ 26-27 May 2015. For full paper see: http://www.nature.org.au/healthy-ecosystems/bushfire-program/conferences/%5D