Category Archives: Wetland

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

Restoration and conservation in an iconic National Park – UPDATE of EMR feature

David Lindenmayer, Chris MacGregor, Natasha Robinson, Claire Foster, and Nick Dexter

[Update of EMR feature – David B. Lindenmayer, Christopher MacGregor, Nick Dexter, Martin Fortescue and Peter Cochrane (2013)  Booderee National Park Management: Connecting science and management.  Ecological Management & Restoration, 14:1, 2-10. https://onlinelibrary.wiley.com/doi/10.1111/emr.12027]

Keywords: Invasive animal and plant control, reintroduction, monitoring

Introduction. Booderee National Park is an iconic, species-rich, coastal reserve that supports a range of threatened and endangered native animals and plants. Several key management actions have been implemented to promote the conservation of biodiversity in Booderee National Park. These include the control of an exotic predator (the Red Fox Vulpes vulpes), the control of highly invasive Bitou Bush (Chrysanthemoides monilifera subsp. rotundata), the management of fire, and the reintroduction of previously extinct native mammals. A key part of work at Booderee National Park has been a long-term monitoring program that commenced in late 2002 and which has aimed to quantify the effectiveness of major management interventions, including the four listed above. The monitoring program has documented the long-term trajectories of populations of birds, arboreal marsupials, terrestrial mammals, reptiles, frogs and native plants in a range of major vegetation types (from heathland and sedgeland to woodland, forest and rainforest) and in response to fire, and weed and feral predator control. Importantly, the monitoring program has provided a foundational platform from which a suite of post-graduate studies and other research programs have been completed.

Further works undertaken. A key part of the researcher-manager partnership has been to analyse the long-term trajectories of populations of mammals, birds and reptiles in Booderee National Park. The monitoring data indicate that many species of mammals are declining, with some having become recently locally extinct (e.g. Greater Glider Petauroides volans) or close to extinction in the reserve (e.g. Common Ringtail Possum Pseudocheirus peregrinus) . This is despite populations of these species persisting in nearby reserves.  Robust interrogation of the multi-taxa monitoring data has been unable to identify reasons for these declines. Interestingly, the declines observed for mammals have not been observed to date in other vertebrate groups, including birds, reptiles and amphibians. An experimentally-based reintroduction program for the Greater Glider aims to not only re-establish populations of the species in Booderee National Park, but also to identify the reasons for the original decline. That program will be in addition to reintroduction programs already underway for other mammal species, the Long-nosed Potoroo (Potorous tridactylus), the Southern Brown Bandicoot (Isoodon obesulus) and Eastern Quoll (Dasyurus vivverinus) that used to inhabit Booderee National Park but which went extinct many decades earlier.

Additional research being undertaken in Booderee National Park has included: (1) studies of the effectiveness of control efforts for Bitou Bush and associated recovery of native vegetation and native fauna, (2) the interactive effects of fire and browsing on native plants and an array of animal groups, and (3) studies of leaf litter and other fuel dynamics in relation to previous fire history and macropod browsing.

Figure 1. Key area of Booderee National Park showing an area of coastal forest before and after Bitou Bush treatment.

Further results to date. Research and monitoring in the past six years have resulted in many new insights including some of considerable value for informing restoration programs. A small subset of these findings is outlined below.

  • Conventional approaches to the control of invasive Bitou Bush entail spraying ultra-low volume herbicide (Fig. 1), followed by burning of the “cured” dead material, and then respraying of the seedlings that germinate after fire. This spray-burn-spray protocol is both the most ecologically effective and the most cost-effective way of controlling Bitou Bush and, at the same time, facilitates the recovery of native vegetation. More recent analysis has revealed spray frequency as the most important determinant of long-term control. There are mixed effects of control methods on native species; plant species abundance was positively related to Bitou Bush control, while native bird abundance (except for Eastern Bristlebird Dasyornis brachypterus, Fig 2.) and mammal abundance were weakly negatively associated with Bitou control.
  • There can be strong interactions between the occurrence of fire and browsing by macropods on native plants as well as particular groups of animals such as spiders.
  • Reintroduction programs for the Southern Brown Bandicoot and Eastern Quoll have been relatively successful, although the latter species suffers high rates of mortality, particularly as a result of fox predation and collisions with motor vehicles. Nevertheless, populations of both species have survived over multiple years and reproduced successfully.

Figure 2. The Eastern Bristlebird, a species for which Booderee National Park is a stronghold. Notably, the species responds positively to management interventions to control Bitou Bush. (Photo Graeme Chapman)

Lessons learned and future directions. The work at Booderee National Park is a truly collaborative partnership between reserve managers, a university and the local Indigenous community.  A key part of the enduring, long-term success of the project has been that a full-time employee of The Australian National University has been stationed permanently in the Parks Australia office in the Jervis Bay Territory. That person (CM) works on an almost daily basis within Booderee National Park and this provides an ideal way to facilitate communication of new research and monitoring results to managers. It also enables emerging management concerns to be included as part of adaptive monitoring practices.

One of the key lessons learned from the long-term work has been the extent of ecological “surprises” – that is, highly unexpected results, including those which continue to remain unexplained. An example is the rapid loss of the Greater Glider and the major decline in populations of the Common Ringtail Possum. One of the clear benefits of this integrated monitoring-management team has been the rapid response to emerging threats. For example in response to high rates of mortality of reintroduced Eastern Quolls, control of the Red Fox was intensified within the park and greater cross-tenure control efforts with neighbouring private and public land managers have commenced. Regular evaluation of monitoring data and management actions has also enabled careful examination of the kinds of risks that can compromise reintroduction programs. These and other learnings will inform other, future reintroduction and translocation programs that are planned for Booderee National Park such as that for the Greater Glider.

Stakeholders and funding bodies. Ongoing work has been supported by many funding bodies and partners. These include the Wreck Bay Aboriginal Community who are the Traditional Owners of Booderee National Park as well as Parks Australia who co-manage the park with the Wreck Bay Aboriginal Community. Other key funders include the Department of Defence, the Thomas Foundation, The National Environmental Science Program (Threatened Species Recovery Hub), the Australian Research Council, the Margaret Middleton Foundation, and the Norman Wettenhall Foundation. Partnerships with Rewilding Australia, Taronga Conservation Society, WWF Australia, NSW Forestry Corporation and various wildlife sanctuaries have been instrumental to reintroduction programs.

Contact information. David Lindenmayer, Chris MacGregor, Natasha Robinson and Claire Foster are with the National Environmental Science Program (Threatened Species Recovery Hub), Fenner School of Environment and Society, The Australian National University (Canberra, ACT, 2601, david.lindenmayer@anu.edu.au). Nick Dexter is with Parks Australia, Jervis Bay Territory, Australia, 2540.

The Tiromoana Bush restoration project, Canterbury, New Zealand

Key words: Lowland temperate forest, animal pest control, weed control, restoration plantings, public access, cultural values, farmland restoration

Introduction. Commencing in 2004, the 407 ha Tiromoana Bush restoration project arose as part of the mitigation for the establishment of the Canterbury Regional Landfill at Kate Valley, New Zealand. The site lies one hour’s drive north of Christchurch City in North Canterbury coastal hill country (Motunau Ecological District, 43° 06’ S, 172° 51’ E, 0 – 360 m a.s.l.) and is located on a former sheep and beef farm.

Soils are derived from tertiary limestones and mudstones and the site experiences an annual rainfall of 920mm, largely falling in winter. The current vegetation is a mix of Kānuka (Kunzea robusta) and mixed-species shrubland and low forest, restoration plantings, wetlands, Gorse (Ulex europaeus) and European Broom (Cytisus scoparius) shrubland and abandoned pasture. Historically the area would have been forest, which was likely cleared 500-700 years ago as a result of early Māori settlement fires. A total of 177 native vascular plant and 22 native bird species have been recorded, including four nationally threatened species and several regionally rare species.

Before and after photo pair (2005-2018). showing extensive infilling of native woody vegetation on hill slopes opposite, restoration plantings in the central valley, and successional change from small-leaved shrubs to canopy forming trees in the left foreground. (Photos David Norton.)

 

Project aims. The long-term vision for this project sees Tiromoana Bush, in 300 years, restored to a: “Predominantly forest ecosystem (including coastal broadleaved, mixed podocarp-broadleaved and black beech forests) where dynamic natural processes occur with minimal human intervention, where the plants and animals typical of the Motunau Ecological District persist without threat of extinction, and where people visit for recreation and to appreciate the restored natural environment.”

Thirty-five year outcomes have been identified that, if achieved, will indicate that restoration is proceeding towards the vision – these are:

  1. Vigorous regeneration is occurring within the existing areas of shrubland and forest sufficient to ensure that natural successional processes are leading towards the development of mature lowland forest.
  2. The existing Korimako (Bellbird Anthornis melanura) population has expanded and Kereru (Native Pigeon Hemiphaga novaeseelandiae) are now residing within the area, and the species richness and abundance of native water birds have been enhanced.
  3. The area of Black Beech (Fuscospora solandri) forest has increased with at least one additional Black Beech population established.
  4. Restoration plantings and natural regeneration have enhanced connectivity between existing forest patches.
  5. Restoration plantings have re-established locally rare vegetation types.
  6. The area is being actively used for recreational, educational and scientific purposes.

Day-to-day management is guided by a five-year management plan and annual work plans. The management plan provides an overview of the approach that is being taken to restoration, while annual work plans provide detail on the specific management actions that will be undertaken to implement the management plan.

Forest restoration plantings connecting two areas of regenerating Kānuka forest. Photo David Norton.

 

Restoration approach and outcomes to date. The main management actions taken and outcomes achieved have included:

  • An Open Space Covenant was gazetted on the title of the property in July 2006 through the QEII National Trust, providing in-perpetuity protection of the site irrespective of future ownership.
  • Browsing by cattle and sheep was excluded at the outset of the project through upgrading existing fences and construction of new fences. A 16 km deer fence has been built which together with intensive animal control work by ground-based hunters has eradicated Red Deer (Cervus elaphus) and helped reduce damage caused by feral pigs (Sus scrofa domesticus).
  • Strategic restoration plantings have been undertaken annually to increase the area of native woody and wetland vegetation, as well as providing food and nesting resources for native birds. A key focus of these has been on enhancing linkages between existing areas of regenerating forest and re-establishing rare ecosystem types (e.g. wetland and coastal forest).
  • Annual weed control is undertaken focusing on species that are likely to alter successional development (e.g. wilding conifers, mainly Pinus radiata, and willows Salix cinerea and fragilis) or that have the potential to smother native regeneration (e.g. Old Man’s Beard Clematis vitalba). Gorse and European Broom are not controlled as they act as a nurse for native forest regeneration and the cost and collateral damage associated with their control will outweigh biodiversity benefits.
  • Establishment of a public walking track was undertaken early in the project and in 2017/2018 this was enhanced and extended, with new interpretation included. Public access has been seen as a core component of the project from the outset so the public can enjoy the restoration project and access a section of the coastline that is otherwise relatively inaccessible.
  • Part of the walkway upgrade included working closely with the local Māori tribe, Ngāi Tūāhuriri, who have mana whenua (customary ownership) over the area. They were commissioned to produce a pou whenua (land marker) at the walkway’s coastal lookout. The carvings on the pou reflect cultural values and relate to the importance of the area to Ngāi Tūāhuriri and especially values associated with mahinga kai (the resources that come from the area).
  • Regular monitoring has included birds, vegetation and landscape, with additional one-off assessments of invertebrates and animal pests. Tiromoana Bush has been used as the basis for several undergraduate and postgraduate student research projects from the two local universities.
Vigorous regeneration of Mahoe under the Kānuka canopy following exclusion of grazing animals. Photo David Norton.

 

Lessons learned. Important lessons learned over the 15-years have both shaped the approach to management at this site and have implications for the management of other projects:

  • Control of browsing mammals, both domestic and feral, has been essential to the success of this project. While domestic livestock were excluded at the outset of the project, feral Red Deer and pigs have the potential to seriously compromise restoration outcomes and these species have required additional management inputs (fencing and culling).
  • Since removal of grazing, the dominant exotic pasture grasses, especially Cocksfoot (Dactylis gomerata), now form tall dense swards. These swards severely restrict the ability of native woody plants to establish and herbicide control is used both pre- and post-planting to overcome this. During dry summers (which are common) the grass sward is also a significant fuel source and the walkway is closed during periods of high fire risk to avoid accidental fires which would decimate the restoration project.
  • Regular monitoring is important for assessing the biodiversity response to management. Annual photo-monitoring now spanning 15-years is highlighting significant changes in land cover across the site, while more detailed monitoring of plants and birds is strongly informing management actions. For example, seven-years of bird monitoring has indicated an ongoing decline in some native birds that is most likely due to predation (by cats, mustelids, rodents, hedgehogs). As a result, a predator control programme is commencing in 2019.
  • Simply removing grazing pressure from areas of existing regenerating native woody vegetation cannot be expected to result in the return of the pre-human forest because of the absence of seed sources. Permanent plots suggest that Kānuka is likely to be replaced by Mahoe (Melicytus ramiflorus), with few other tree species present. Gap creation and enrichment planting is therefore being used to speed up the development of a more diverse podocarp-angiosperm forest canopy.
Kate Pond on the Tiromoana Bush walkway. The pond and surrounding wetland provides habitat for several native water birds. Photo Jo Stilwell.
The pou whenua on the coastal lookout platform looking north up the coastline. Photo David Norton.

 

Looking to the future. Considerable progress in restoring native biodiversity at Tiromoana Bush has been achieved over the last 15 years and it seems likely that the project will continue to move towards achieving its 35-year outcomes and eventually realising the long-term vision. To help guide management, the following goals have been proposed for the next ten-years and their achievement would further help guarantee the success of this project:

  • The main valley floor is dominated by regenerating Kahikatea (Dacrycarpus dacrydioides) forest and wetland, and the lower valley is dominated by regenerating coastal vegetation.
  • At least one locally extinct native bird species has been reintroduced.
  • Tiromoana Bush is managed as part of a wider Motunau conservation project.
  • The restoration project is used regularly as a key educational resource by local schools.
  • The walkway is regarded as an outstanding recreational experience and marketed by others as such.
  • Tiromoana Bush is highly valued by Ngāi Tūāhuriri.
Kereru, one of the native birds that restoration aims to help increase in abundance. Photo David Norton.

 

Stakeholders and funding. The project is funded by Transwaste Canterbury Ltd., a public-private partnership company who own the landfill and have been active in their public support for the restoration project and in promoting a broader conservation initiative in the wider area. Shareholders of the partnership company are Waste Management NZ Ltd, Christchurch City Council and Waimakariri, Hurunui, Selwyn and Ashburton District Councils.

Contact Information. Professor David Norton, Project Coordinator, School of Forestry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand. Phone +64 (027) 201-7794. Email david.norton@canterbury.ac.nz

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

A framework and toolbox for assessing and monitoring swamp condition and ecosystem health

Key words: Upland swamp, stygofauna, sedimentology, ecosystem processes, biological indicators, geomorphology

Introduction. Upland swamps are under increasing pressure from anthropogenic activities, including catchment urbanization, longwall mining, and recreational activities, all under the omnipresent influence of global climate change. The effective management of upland swamps, and the prioritisation of swamps for conservation and restoration requires a robust means of assessing ecosystem health. In this project we are developing a range of ecological and geomorphic indicators and benchmarks of condition specifically for THPSS. Based on a multi-metric approach to ecosystem health assessment, these multiple indicators and benchmarks will be integrated into an ultimate index that reflects the health of the swamp.

In this project we have adopted (and modified) the definition of ecosystem health applied to groundwater ecosystems by Korbel & Hose (2011). We define ecosystem health of a swamp as, i.e., “an expression of a swamp’s ability to sustain its ecological functioning (vigour and resilience) in accordance with its organisation while maintaining the provision of ecosystem goods and services”.

Design. Our approach to develop indicators of swamp health followed those used to develop multimetric indices of river and groundwater ecosystem health (e.g. Korbel & Hose 2011). We used the ‘reference condition’ approach in which a number of un- or minimally disturbed swamps were sampled and the variation in the metric or index then represents the range of acceptable conditions (Bailey et al. 1998; Brierley & Fryirs 2005).

We focused initially on swamps in the Blue Mountains area. Reference (nominally unimpacted) and test sites with various degrees and types of impacts were identified using the database developed by the concurrent THPSS mapping project (Fryirs and Hose, this volume).

Following our definition of ecosystem health, we selected a broad suite of indicators that reflect the ecosystem structure (biotic composition and geomorphic structure) and function, including those relating to ecosystem services such as microbially-mediated biogeochemical functions, geomorphic processes and hydrological function, as well as the presence of stressors, such as catchment changes. Piezometers and dataloggers have been installed in a number of swamps to provide continuous data on groundwater level fluctuations and sediment cores taken at the time of piezometer installation have provided detailed information on the sedimentary structure, function and condition of the swamps.

Results. Intact and channelised swamps represent two geomorphic condition states for THPSS. Not surprisingly, variables reflecting the degree of catchment disturbance (such as urbanization) were strongly correlated with degraded swamp condition. Variables related to the intrinsic properties of swamps had little relationship to their geomorphic condition (Fryirs et al. 2016). Intact and channelized swamps present with typically different sediment structures. There were significant differences in the texture and thickness of sedimentary layers, C: N ratios and gravimetric moisture content between intact swamps and channelised swamps (Friedman & Fryirs 2015). The presence and thickness of a layer of contemporary sand in almost all channelised swamps and its absence in almost all intact swamps is a distinctive structural difference.

Disturbed swamps have poorer water quality at their downstream end, and associated with this, lower rates of organic matter processing occurring within the streams (Hardwick unpublished PhD Data). Similarly, the richness and abundance of aquatic invertebrates living within swamp sediments (stygofauna) is poorer in heavily disturbed swamps than in undisturbed or minimally disturbed areas (Hose unpublished data).

Within the swamp sediments, important biogeochemical processes, such as denitrification and methanogenesis, are undertaken by bacteria. In this study we are measuring the abundance of the functional genes such as a surrogate for functional activity within the swamp sediments. There is large spatial variation in the abundance of functional genes even within a swamp, which complicates comparisons between swamps. Within our focus swamp, the location closest to large stormwater outlets had different functional gene abundances, in particular more methanogens, than in less disturbed areas of the swamp. There were greater abundances of denitrification genes, nirS and nosZ, in shallower depths despite denitrification being an anoxic process, which may reflect changes in the surficial sediments due to disturbance. Overall however, the abundance of functional genes seem to vary more with depth than with location, which means that comparisons between swamps must ensure consistency of depth when sampling sediments (Christiansen, unpublished PhD data).

The list of indicators currently being tested in this project and by others in this program (Table 1) will be refined and incorporated into the final assessment framework. Thresholds for these indicators will be determined based on the range of conditions observed at the reference sites. The overall site health metric will reflect the proportion of indicators which pass with respect to the defined threshold criteria. At this stage, the final metrics will be treated equally, but appropriate weightings of specific metrics within the final assessment will be explored through further stakeholder consultation.

Stakeholders and Funding bodies. This research has been undertaken as PhD research projects of Kirsten Cowley, Lorraine Hardwick and Nicole Christiansen at Macquarie University. The research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program. This project was also partly funded by an ARC Linkage Grant (LP130100120) and a Macquarie University Research and Development Grant (MQRDG) awarded to A/Prof. Kirstie Fryirs and A/Prof. Grant Hose at Macquarie University. We also thank David Keith, Alan Lane, Michael Hensen, Marcus Schnell, Trevor Delves and Tim Green.

Contact information. A/Prof. Grant Hose, Department of Biological Sciences, Macquarie University (North Ryde, NSW 2109; +61298508367; grant.hose@mq.edu.au); and A/Prof. Kirstie Fryirs, Department of Environmental Sciences, Macquarie University (North Ryde, NSW 2109; +61298508367; kirstie.fryirs@mq.edu.au).

Table 1. List of indicators of swamp condition that are being trialled for inclusion in the swamp health assesment toolbox.

Functional indicators table

Testate amoebae: a new indicator of the history of moisture in the swamps of eastern Australia

Key words: Temperate Highland Peat Swamps Sandstone

Introduction. Swamps are an ideal natural archive of climatic, environmental and anthropogenic change. Microbes and plants that once inhabited the swamps are transformed and accumulate in undisturbed anoxic sediments as (sub)fossils and become useful proxies of the past environment. Since these systems are intrinsically related to hydrology, the reconstruction of past moisture availability in swamps allows examination of many influences, including climate variability such as El Nino-induced drought. It can also provide baseline information: long (palaeoenvironmental) records can reveal natural variability, allow consideration of how these ecosystems have responded to past events and provide targets for their restoration after anthropogenic disturbance.

Testate amoebae are a group of unicellular protists that are ubiquitous in aquatic and moist environments. The ‘tests’ (shells) of testate amoebae preserve well and are relatively abundant in organic-rich detritus. Testate amoebae are also sensitive to, and respond quickly to, environmental changes as the reproduction rate is as short as 3-4 days. Modern calibration sets have demonstrated that the community composition of testate ameobae is strongly correlated to moisture (e.g. depth to water table and soil moisture) and this allows statistical relationships to be derived. These relationships have been used extensively in European research for the derivation of quantitative estimates of past depth to water table and hence moisture availability.

Although a suite of different proxies have used to reconstruct aspects of past moisture availability in Australia (e.g. pollen, diatoms, phytoliths) very little work on testate amoebae has occurred to date. This project aims to address this deficiency by examining testate amoebae in several ecologically important mires in eastern Australia including Temperate Highland Peat Swamps on Sandstone (THPSS), an Endangered Ecological Community listed under the Environment Protection and Biodiversity Conservation Act 1999 and as a Vulnerable Ecological Community under the NSW Threatened Species Conservation Act 1995.

The project specifically aims to develop a transfer function linking modern samples to depth to water table in THPSS and to then apply this to reconstruct palaeohydrology over the last several thousand years. Our ultimate aims are to use this research to consider the nature and drivers of past climate change and variability and to also address issues associated with recent human impacts. The analysis of testate amoebae will allow us to consider changes in THPSS state, accumulation and stability over centuries-to-millennia, and this will provide context for recent changes, recommendations for the management of peaty swamps on sandstone and analytic tools for assessing whether remediation is resulting in significant improvement on eroding or drying swamps.

Work Undertaken and Results to Date. Research linking testate amoebae and depth to water table in Europe and North America has mostly been undertaken in ombrotrophic (rain-fed) mires. These are distinctly different to THPSS and related communities of the Sydney Basin, which are often controlled by topography (topogeneous mires). In these environments various sediments are known to build up sequentially through time and the minerogenic-rich sediments of the THPSS have resulted in several challenges in our preliminary work. As an example, standard laboratory protocols do not remove mineral particles and these can obscure and make testate amoebae identification difficult. We have since developed a new laboratory protocol and results are promising. We have also been struck by the distinct Northern Hemisphere bias to testate amoebae research: as an example, the Southern Hemisphere endemic species Apodera (Nebela) vas that has been common in our THPSS samples is not included in the most popular guideline book (https://www.qra.org.uk/media/uploads/qra2000_testate.pdf).

Despite the new laboratory protocols we have found that testate amoebae are relatively scarce in THPSS environments. Table 1 outlines the species we are encountering in modern (surface) samples of THPSS and in the high altitude Sphagnum bogs of the Australian Capital Territory: we are finding greater abundance and species richness in the bogs of the ACT.

This project commenced in 2015 and will run until 2017.

Stakeholders and Funding. This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact information. The project testate amoebae as indicators of peatland hydrological state’ is jointly being undertaken by: A/Prof Scott Mooney (School of Biological, Earth and Environmental Science, UNSW +61 2 9385 8063, s.mooney@unsw.edu.au), Mr Xianglin Zheng (School of Biological, Earth and Environmental Science, UNSW, +61 2 9385 8063, xianglin.zheng@unsw.edu.au) and Professor Emeritus Geoffrey Hope (Department of Archaeology and Natural History, School of Culture, History, and Language, College of Asia and Pacific, The Australian National University, +61 2 6125 0389 Geoffrey.Hope@anu.edu.au).

Table 1. A list of the testate amoebae species found in THPSS environments of the Sydney region and in the high altitude bogs of the ACT. (Those with a ++ are more common.)

Mooney table1

The palaeoenvironmental history of Temperate Highland Peat Swamps on Sandstone

Scott Mooney, James Goff and Lennard Martin

Key words (<5 words): sediments, palaeoenvironmental reconstruction, radiocarbon dating

Introduction. Palaeoecology (i.e. study of past environments using fossils and sediment cores) is often used to provide information regarding past environmental conditions. In comparison to modern ecological research, the expanded temporal perspective of palaeoecology unlocks an understanding of pre-anthropogenic variability and how ecosystems have responded to past disturbance and perturbations, thereby allowing consideration of their resilience to various environmental change.

Our Temperate Highland Peat Swamps on Sandstone Research Program (THPSSRP) research has investigated a number of sites in the Blue Mountains and on the Newnes Plateau. Our project aimed to use the sediments accumulating in these sandstone swamps to better understand the dynamics of these ecosystems over time frames that far exceed what is possible through environmental monitoring. We have been documenting the stratigraphy of the sediments using probing and sediment coring/sampling, in association with radiometric (14C, 210Pb) dating, and applying various palaeoenvironmental techniques and proxies to characterize these environments. Our ultimate aims were to characterise recent (historic) trends against the backdrop of a much longer temporal perspective from the palaeoenvironmental analyses and to examine the responses of the swamps over both long (since sediments started accumulating) and short (high-resolution) time frames to disturbance, environmental change and climatic variability.

Sydney Basin Meta-study of Accumulating Sediments. The first component of our research involved a meta-analysis of previous data regarding the ages and organic content of sediments in various depositional environments across the Sydney region. Our aim was to consider rates of sediment accumulation in the post-glacial period (the period since the last glacial maximum, about 21,000 years ago): this information informed our subsequent sampling strategies (e.g. depth of coring, resolution of analyses) and can be used in for future research to better target various chronozones. It is probable that rates of sediment accumulation reflect landscape instability/stability and together with organic content, this provides palaeoenvironmental information relevant to the overall aims of this project. For this component we collated and recalibrated radiocarbon dates (n=132) from 44 sites across the Sydney region, and we identified a subset of 12 sites with quantification of the organic content of the accumulating sediments.

Findings. The synthesis of these data revealed that sedimentation rates underwent a dramatic increase from ~0.2 mm/yr to ~0.6 mm/yr at the beginning of the Holocene (about ~11,700 years ago), which probably reflects post-glacial climatic amelioration. Sedimentation rates remained relatively high during the Holocene, between 0. 4 and 0. 5 mm/yr, although brief decreases are evident, for example centred at 8200, 6500, 2000 and 1200 calibrated radiocarbon years before present (cal. y BP). Only in the last 400 cal y BP do sedimentation rates increase above those present for the majority of the Holocene, peaking at 0.7 mm/yr.

In contrast, organic material began accumulating at around 14,400 cal y BP in these depositional environments, earlier than the 11,700 cal BP increase in sedimentation rates. Before this time all sites exhibited relatively low rates of highly minerogenic sedimentation. After ~14,400 cal y BP the organic content of the sites gradually increased in a trajectory that continued throughout the Holocene, albeit with some major excursions from this trend. As an example, organic content peaked between about 7,500 and 6,000 cal y BP, only to fall to a low at about 5,400 cal y BP, which is then followed by a rapid increase to another peak between about 4,500 and 4,000 cal y BP. This last peak in organic content achieves similar values to the surface/modern samples. This peak (6.7ka)-trough (5.4ka)-peak (4.2ka)-trough (3.2ka) sequence suggests considerable variation in the controls of organic matter production and accumulation, which are mostly climatic parameters. The palaeoenvironmental implications of these results are currently being written for submission to a scientific journal.

Field–based Sampling. Field-based sampling for this research has focused on stable depositional environments in the Sydney region:

  1. Goochs Crater in the Upper Blue Mountains. This site appears to have formed after a rock fall dammed the upper reaches of a relatively narrow valley/canyon. The site is presently a freshwater reed swamp with semi-permanent surface water, although the site has both flooded and burnt since first we first visited. After investigating the stratigraphy and depth of the accumulating sediments, three cores have been collected (G1,G2 & G3) along a transect from the edge to the centre. G1 is a 455 cm long core sampled close to the current waters edge: radiocarbon dating indicates that this represents from the present day back to about 9,500 cal y BP. This core is mostly organic-rich (>60% loss-on-ignition) but these authochthonous sediments are interspersed with abrupt (allochthonous) layers of sand and charcoal, probably transported to this location after major fire events. Our G2 core is 985 cm long and spans the period from about 4,000 to 17,500 cal y BP: it is also highly organic (20-95% loss-on-ignition) but does not include sand/charcoal layers. Core G3 extended down to highly minerogenic sediments at a depth of 795 cm and has a very similar stratigraphy to core G2.
  2. Queens Swamp near Lawson in the Blue Mountains. Queens Swamp was (re-)cored to a depth of 3.8 m and the sediment profile revealed alternating layers of sandy and peaty sediments similar to the edge core (G1) from Goochs Crater. Radiocarbon dating of the Queens Swamp cores suggests a rapidly accumulating upper section of sediments overlying a much older basal layer.
  3. Hanging Rocks Swamp located in Penrose State Forest in the Southern Highlands. A 5.6 m sediment core was also obtained Hanging Rock Swamp and these sediments returned a basal date of 14,500 cal y BP.

Field observations and preliminary results from fieldwork have been published in Quaternary Australasia and Australian Plant Conservation.

Radiocarbon Dating of Sediments. Our THPSS research has involved 35 new radiocarbon (14C) analyses so far across the three sites (Goochs, Queens, Hanging Rock) mentioned above, with a few more planned soon. Twenty of these dates resulted from two AINSE grants, which allowed accelerator mass spectrometry (AMS) 14C dates. This dating was undertaken to develop robust chronologies of the sediments so that palaeoenvironmental changes could be well constrained, but we also undertook some experimentation to consider the optimum sediment fraction for future 14C dating. The sediment fractions considered were charcoal, pollen and short-lived plant macrofossils that were all isolated from the same depth in the sediment profiles. Preliminary results, in preparation for submission at the moment, suggest that charcoal has an inbuilt age of 60-500 years and plant macrofossils return an age closest to the true (modeled) age of that depth.

Preliminary Palaeoenvironmental Interpretation and Conclusions. A variety of palaeoenvironmental techniques have been applied to the sediments sampled from Goochs Crater and together they provide information about past environmental conditions. As an example, sediment humification, which provides clues to surface moisture conditions at the time of deposition, suggests that the period from 9,500 to 7,500 cal y BP was relatively dry, which contrasts with previous palaeoclimatic inferences for this region. As different photosynthetic and metabolic pathways mean that the ratio of carbon/nitrogen can distinguish between aquatic and terrestrial sources of organic matter we analysed this ratio in 32 samples across the G2 core from Goochs Crater. These results suggests that aquatic sources of organic material dominated from 17,500 to 15,000 cal y BP and between 15,000 to 10,000 cal y BP conditions favored both aquatic and terrestrial sources. A rapid departure to highly terrestrial sources was evident at 10,000 cal y BP, after which a gradual change towards contemporary conditions, with a small aquatic influence, was evident.

While this demonstrates that much of the (contemporary) accumulating sediments at Goochs Crater are derived from within the site, it also receives inorganic aeolian materials from a larger source area.  To investigate this component we quantified the grainsize along the sediment profile to reveal that although clay content remains near constant (~ 5%) for the entire period, sand-sized particles shows a distinct increase in the period between 10,000 and 7,000 cal y BP before disappearing from the record. X-ray fluorescence scanning was also conducted on the G2 core resulting in elemental profiles for 32 elements at a very high (1mm) resolution. While the geochemical investigation of peat and organic sediments is in its infancy, several elements show considerable promise as palaeoenvironmental proxies. In our record, titanium, probably resulting from freshly weathered materials and washed in during periods of high surface runoff, is variable between 17,500 and 12,000 cal y BP, followed by sustained low values throughout the Holocene except for an abrupt, brief increase at 10,000 cal y BP followed again by high levels from 9,500 to 8,500 cal y BP. Bromine, which indicates the deposition of marine aerosols, shows an opposite trend to titanium, with low values until the early Holocene when a gradual increase begins, most likely indicating increased maritime influence on the hydrology of the site as sea level rose and stabilized in the post-glacial period.

In summary, it appears that Goochs Crater began accumulating organic sediments around 17,500 cal y BP, shortly after which a small, shallow lake developed and persisted in an otherwise sparsely vegetated landscape. The establishment of shoreline vegetation by about 15,000 years ago contributed to the accumulating sediments and this seems to have occurred under a climate of strong but variable westerly winds. A gradual but increasing oceanic influence affected the site until 10,000 cal. BP. before abrupt drying occurred. Increased sand present in the record during the early Holocene and other information suggests a relatively dry period. During the rest of the Holocene, the site returned to a wet, swampy environment: we are currently re-analysing the edge core with a broader suite of proxies to better characterize the late Holocene and it is envisaged that this will result in a complete moisture-focused palaeoenvironmental record from the site from 17,500 cal. BP to present. In the rest of this project (it will run until the end of 2016) we will finalize the interpretation of the other sites and the synthesis will provide a regional picture of palaeoclimatic influences on these important ecological communities. This work will also be compared to high-resolution fire histories that are being developed across the region.

Stakeholders, Funding and Acknowledgements. This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program. This work has benefited from discussion with Martin Krogh, Doug Benson, Sarsha Gorissen, Geoff Hope, Roger Good and Jennie Whinam.  This work has also been supported by a 2014 and 2015 AINSE Research Award (ALNGRA14019 and 15019) to SM.

Contact information. The project ‘Palaeoenvironments of sandstone peat’ is being undertaken by A/Prof Scott Mooney (School of Biological, Earth and Environmental Science (BEES) UNSW +61 2 9385 8063, s.mooney@unsw.edu.au), Professor James Goff  (School of BEES UNSW j.gof@unsw.edu.au) and Mr Len Martin (PhD candidate, School of BEES, UNSW, +61 2 9385 8063, lennard@student.unsw.edu.au).

A novel multispecies approach for assessing threatened swamp communities

Hannah McPherson and Maurizio Rossetto,

Key words:   Swamp conservation, chloroplast DNA, genetic diversity, landscape connectivity

Introduction. Little is known about the historical or present-day connectivity of Temperate Highland Peat Swamps on Sandstone (THPSS) in the Sydney Basin (NSW). Recent technological advances have enabled exploration of genetic complexity at both species and community levels.  By focusing on multiple plant species and populations, and investigating intraspecific gene-flow across multiple swamps, we can begin to make generalisations about how species and communities respond to change, thereby providing a solid scientific basis from which appropriate conservation and restoration strategies can be developed.

The study area comprised eight swamps distributed across four sites along an altitudinal gradient: Newnes (1200m); Leura (900m); Budderoo (600m); and Woronora (400m), see figure 1.

Map of the Sydney Basin region showing four study sites and eight swamps. Greyscale shows altitude gradient.

Map of the Sydney Basin region showing four study sites and eight swamps. Greyscale shows altitude gradient.

The aims were:

  • To assess the relative genomic diversity among target species representing a range of life-history traits. This was achieved by sequencing chloroplast DNA and detecting variants in pooled samples from 25 species commonly occurring in swamps.
  • To explore geographic patterns of diversity among swamps and across multiple species by designing targeted genomic markers and screening variants among populations within and between sites (for ten species occurring in up to 8 swamps).
  • To develop a set of simple, effective and standardised tools for assessing diversity, connectivity and resilience of swamps to threats (from mining to climate change).
Fig 2. Broad Swamp, Newnes Plateau (Maurizio Rossetto)

Fig 2. Broad Swamp, Newnes Plateau (Maurizio Rossetto)

Our study comprises three main components:

1. Species-level assessment of genetic variation of swamp species

We have taken advantage of new available methods and technologies (McPherson et al. 2013 and The Organelle Assembler at http://pythonhosted.org/ORG.asm/) to sequence and assemble full chloroplast genomes of 20 plant species from swamps in the Sydney Basin and detect within and between-population variation. This enabled a rapid assessment of diversity among representatives of 12 families and a broad range of life-history traits – e.g. table 1. We are currently finalising our bioinformatic sampling of the data to ensure even coverage of chloroplast data across the species, however these preliminary data show that relative estimates are not a product of different amounts of chloroplast data retrieved (e.g. for the seven species with sequence length greater than 100,000 base pairs variation ranges from absent to high).

2. Swamp-level assessment of variation and connectivity using three target species – Baeckea linifolia (high diversity), Lepidosperma limicola (low diversity) and Boronia deanei subsp. deanei (restricted and threatened species).

From the initial species-level study we selected three very different species for detailed population-level studies. We designed markers to screen for variation within and among sites and explore landscape-level connectivity. We identified the Woronora Plateau as a possible refugium and we have uncovered interesting patterns of gene-flow on the Newnes Plateau. Two species, Lepidosperma limicola and Baeckea linifolia seem able to disperse over long distances while Boronia deanei subsp. deanei showed unexpected high levels of diversity despite very limited seed-mediated gene-flow between populations. Its current conservation status was supported by our findings. A unique pattern was found for each species, highlighting the need for a multispecies approach for understanding dynamics of this system in order to make informed decisions about, and plans for, conservation management.

3. Multi-species approach to assessing swamp community population dynamics

Since the population study approach proved successful we expanded our study to include population studies for a further ten species. This required development of new Next Generation Sequencing (NGS) approaches applicable to a wide range of study systems. This kind of approach will allow us to make informed generalisations about swamp communities for conservation management planning.

Fig 3. Paddy’s Swamp, Newnes Plateau (Anthea Brescianini)

Fig 3. Paddy’s Swamp, Newnes Plateau (Anthea Brescianini)

Table 1. Preliminary results showing relative chloroplast variation among 25 swamp species. Sequence length is in base pairs (bp) and relative level of variation was calculated as sequence length divided by number of variants to obtain an estimate of number of SNPs per base pair.  Relative variation was then categorised as: High (one SNP every <1,000 bp); Moderate (one SNP every 1,000 – <5,000 bp); Low (one SNP every 5,000 – <10,000 bp); Very low (one SNP every >10,000 bp); or absent (no SNPs).

table

Fig 4. Banksia ericifolia (Maurizio Rossetto)

Fig 4. Banksia ericifolia (Maurizio Rossetto)

Results to date. We have assembled partial chloroplast genomes of 20 plant species from THPSS in the Sydney Basin and categorised relative measurements of diversity. Preliminary data from the three target species highlighted the need for multispecies studies and we are now finalizing our results from an expanded study (including 13 species) in order to better understand connectivity and resilience of THPSS and provide data critical for more informed conservation planning. We have produced unique, simple methods for assessing genetic diversity and understanding dynamics at both the species and site levels.

Lessons learned and future directions. We found that individual species have unique patterns of genetic variation that do not necessarily correspond with phylogeny or functional traits and thereby highlight the benefit of multispecies studies. We have developed a unique, simple method for screening for genetic variation across whole assemblages which can be applied to many study systems. Since our data capture and analysis methods are standardised it will be possible in the future to scale this work up to include more species and/or more geographic areas and analyse the datasets together to address increasingly complex research questions about the resilience of swamps in a changing landscape.

Stakeholders and Funding bodies. The following people have contributed to many aspects of this research, including design, fieldwork and data generation and analysis: Doug Benson and Joel Cohen (Royal Botanic Gardens and Domain Trust), Anthea Brescianini and Glenda Wardle (University of Sydney), David Keith (Office of Environment and Heritage).

This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd. Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact. Hannah McPherson, Biodiversity Research Officer, Royal Botanic Gardens and Domain Trust, Mrs Macquaries Road, Sydney 2000; Tel: +61292318181 Email: hannah.mcpherson@rbgsyd.nsw.gov.au

Hydrology of Woronora Plateau Temperate Highland Peat Swamps on Sandstone

William C Glamore and Duncan S Rayner

Key words: water balance, groundwater, soil, subsidence, under mining

Introduction. The Temperate Highland Peat Swamps on Sandstone (THPSS) ecological community consists of both temporary and permanent swamps developed in peat overlying Triassic Sandstone formations at high elevations, generally between 400 and 1200 m above sea level on the south-east coast of Australia. THPSS are listed as an endangered ecological community (EEC), threatened by habitat destruction and modification of groundwater and hydrology. The primary impact of longwall mining is to swamp hydrology, influencing long-term surface and groundwater regimes. This, in turn, can have a devastating impact on swamp ecology including many important habitats for protected flora and fauna. While the ecological value of THPSS is well understood, our current understanding of the hydrology of THPSS is limited. THPSS have been found to be dependent on groundwater, and subsequently the impact of modifying groundwater interactions can be significant. Recent research has concluded that a thorough understanding of the impact of longwall mining on the surface waterways and groundwater system is necessary before any remediation options to reduce loss of water into subsurface routes and minimise impact on water quality are considered.

Aims. To address this major knowledge gap, research into the fundamental hydrology of THPSS was undertaken. The purpose of this investigation was to understand the role of surface water and groundwater inputs and losses in maintaining swamp hydrology, providing a base level foundation from which the impacts of long-wall mining on ecology can be determined and guide future remediation efforts. To undertake on-ground research, multiple locations where data collection in peat swamps was being undertaken were utilised to form a foundation from which to expand swamp investigations and target site data gaps. Two swamps were selected for further detailed investigations, both located on the Woronora Plateau, approximately 80km south of Sydney, Australia. One site was within the Woronora Nature Reserve, where vegetation has been monitored regularly for 30+ years and basic climate monitoring for the past 5 years, and another swamp within the Sydney Metropolitan Catchment Management Area where climate monitoring, groundwater levels and swamp discharge has been monitored for the previous 5 years.  Extensive on-ground investigations were undertaken (and continue to be monitored) at these sites, providing fundamental scientific information for further assessment.

Methods. A series of groundbreaking on-ground investigations were undertaken to characterize the swamp hydrogeology and surface hydrology.  Detailed surveys of peat depth were initially undertaken using a push rod and RTK-GPS to determine digital elevation models (DEM) of surface topography and subsurface sandstone. Depth to underlying sandstone was found to be variable throughout the swamps (Figure 1). This survey guided the location and density of soil profiles and piezometer installations to characterize sediment characteristics, monitor water level fluctuations and assess water and soil chemistry.  A total of 17 piezometers were installed to bed rock, including logging soil stratigraphy and soil grab samples. Slotted 50mm diameter PVC was installed with a water level logger deployed near the bedrock. Soil samples were analysed for pH, EC, moisture, organic matter and a suite of analytes via ion chromatography. Hydraulic conductivity of the upper peat layer was also tested in-situ. Collected field data and site characterization surveys were combined to construct a three-dimensional numerical hydrological groundwater model to assist in determining the swamp water balance, hydrodynamics and to refine future sampling/analysis.

Figure 1: Example swamp depth survey and piezometer locations with conceptual groundwater flow paths

Figure 1: Example swamp depth survey and piezometer locations with conceptual groundwater flow paths

Findings. Findings include fundamental swamp hydrogeolgical characteristics, water balance summaries and analysis of degrees of freedom.  Swamp sediments were observed to vary both within swamps and between swamps. Sediment depths were found to range between 0.5 m to 2.6 m deep, with typical peat depths ranging between 30 cm – 100 cm of a dense organic layer in various stages of decomposition. The organic layer is underlain by grey sandy clay with clay content decreasing with depth (Figure 2). Sand and gravel was observed in the 10 cm to 30 cm range above bedrock.  Soil acidity was observed to be relatively uniform over depth with an average pH 5.7, however electrical conductivity and chloride decreased with depth; suggesting evapo-concentration of salts within the upper layers of the swamp. Soil moisture by weight and organic content were measured to decrease with depth, indicating decreasing porosity. Specific yield of swamp surface soils (0 m to 0.2 m) ranged between 15-20%, with deeper sediments (0.2 m to 0.4 m) approximately 10% greater.

Analysis of the water levels across the swamps, in conjunction with preliminary water balance modelling, indicates that despite the current data collection program, significant degrees of freedom remain unaccounted. Key factors such as transpiration, runoff, infiltration, interflow and groundwater losses are currently unknown and present seven sources of uncertainty within the water balance model. To reduce the uncertainty and close the water balance of peat swamps, further long term monitoring and site specific measurements are required. With the addition of soil core samples, soil hydraulic conductivity, long term water level data and further swamp geometry data, eight out of a total of nine water balance quantities will be known for the swamp, enabling increased reliability to assess the impacts of climate change, changes in land use, and undermining on long-term swamp ecology.  The findings from this study provide fundamental information that forms the basis for ongoing investigations critical for understanding peat swamp hydrology.

Figure 2: Typical swamp lithology

Figure 2: Typical swamp lithology

Acknowledgements. This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact. William C Glamore and Duncan S Rayner, Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Australia (110 King St, Manly Vale, NSW 2093, Australia, Tel: +61/ 2 8071 9868. Email: w.glamore@wrl.unsw.edu.au ).

Conservation of an endangered swamp lizard

Key words:         Eulamprus leuraensis, fire impacts, disturbance ecology, habitat requirements, Scincidae

The Blue Mountains Water Skink is known from less than 60 isolated swamps in the Blue Mountains and Newnes Plateau of southeastern Australia (Fig 1). Understanding the species’ ecology, notably its vulnerability to threatening processes such as fire and hydrological disturbance, is essential if we are to retain viable populations of this endangered reptile.

Fig 1. Swamps containing Eulamprus leuraensis used in our baseline surveys (from Gorissen et al., 2015)

Fig 1. Swamps containing Eulamprus leuraensis used in our baseline surveys (from Gorissen et al., 2015)

Design: We surveyed swamps across the species’ known range to identify critical habitat requirements, and to examine responses both of habitat features (vegetation) and lizard populations to fire regimes and other anthropogenic disturbances. Our analyses of fire impacts included both detailed studies post-fire, and GIS-based analyses of correlations between lizard abundance and fire history.

Results to date: Blue Mountains Water Skinks appear to persist wherever suitable swamp habitat is maintained, although lizard numbers decline after frequent fires, hydrological disturbance or urbanization. However, the lizards (especially, adults) rarely venture out from the core swamp habitat into the surrounding woodland matrix. The “fast” life-history of this species (rapid growth, early maturation, high reproductive output) enables populations to recover from local disturbances, but very low vagility means that re-colonisation of a swamp after extirpation of a population is likely to be very slow (if it occurs at all).

Fig 2. Blue Mountains Water Skink within its swamp habitat (Photo: S. Dubey)

Fig 2. Blue Mountains Water Skink within its swamp habitat (Photo: S. Dubey)

Fig 3. Sarsha Gorissen checks a trap for lizards in a Newnes Plateau swamp (Photo: N. Belmer)

Fig 3. Sarsha Gorissen checks a trap for lizards in a Newnes Plateau swamp (Photo: N. Belmer)

Lessons learned and future directions: The suitability of a montane swamp for Blue Mountains Water Skinks can be readily assessed from soil-moisture levels and vegetation characteristics. Effective conservation of this endangered reptile species should focus on conserving habitat quality in swamps, rather than targeting the lizards themselves. If healthy swamps can be maintained, the lizards are unlikely to face extinction. Given high levels of genetic divergence among lizard populations (even from adjacent swamps), we need to maintain as many swamps as possible.

Stakeholders and Funding bodies: This research was funded through the Temperate Highland Peat Swamps on Sandstone Research Program (THPSS Research Program). This Program was funded through an enforceable undertaking as per section 486A of the Environment Protection and Biodiversity Conservation Act 1999 between the Minister for the Environment, Springvale Coal Pty Ltd and Centennial Angus Place Pty Ltd.  Further information on the enforceable undertaking and the terms of the THPSS Research Program can be found at www.environment.gov.au/news/2011/10/21/centennial-coal-fund-145-million-research-program.

Contact information: Prof Richard Shine, School of Life and Environmental Sciences, Heydon-Laurence Building A08, University of Sydney, NSW 2006 Australia. Phone: (61) 2-9351-3772; Email: rick.shine@sydney.edu.au