Category Archives: Planning, monitoring & assessment

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

The spatial distribution and physical characteristics of Temperate Highland Peat Swamps on Sandstone (THPSS)

Key words: wetlands, upland swamp, geomorphology, mapping, Sydney Basin

Effective conservation and management of natural resources requires that we have an understanding of the spatial distribution and physical characteristics of the systems of concern. The results of the THPSS mapping project summarised here provide an essential physical (geomorphological) template atop which a range of other biophysical information on swamp structure, function and condition can be collated and interpreted.

Design. Using a 25 m Digital Elevation Modal (DEM) coupled with orthorectified aerial photography, the THPSS of the Sydney Basin were mapped in ArcGIS. Only valley-bottom swamps were mapped. Hanging swamps or hillslope drapes were excluded. In ArcGIS, the physical attributes of the swamps were attributed and measured. This included swamp area, elevation above sea level, swamp slope, catchment area, swamp and catchment elongation ratio, swamp length and distance to coast.

Figure 1: Regions in which THPSS occur in the Sydney Basin

Figure 1: Regions in which THPSS occur in the Sydney Basin

Results. Five regions of THPSS were mapped (Figure 1); Newnes (Figure 2), Blue Mountains (Figure 3), Budderoo (Figure 4), Woronora (Figure 5) and Gosford (Figure 6). Across these regions there is a total of 3208 individual THPSS. The combined area of these swamps is 101 km2 (10,100 ha) and the combined catchment areas that contain them cover 789 km2. They occur at a median distance of 57 km from the coast, but this is highly varied, ranging from 0.4 – 96 km.

The swamps occur in areas with an average annual rainfall of 1505 mm/year and average annual temperature is 15oC. They occur at a wide range of elevations. Those closer to the coast occur on elevations as low as 160 m ASL, and those further from the coast on plateau country can occur at elevations up to 1172 m ASL. The bulk of these systems occur at median elevations of 634 m ASL. The swamps are elongate in shape, having a median elongation ratio of 0.46. This makes the majority of these systems relatively long (median length is 216 m) and narrow. They occur in relatively elongate catchments with median elongation ratios of 0.61 and median catchment lengths of 488 m. Almost all these valleys terminate at their downstream ends at a valley constriction or bedrock step, making the valleys ‘funnel-shaped’.

Catchment areas draining into the swamps are, on average, 0.25 km2. This means these systems tend to occur in the very headwaters of most catchments in first or second order drainage lines. Each swamp is, on average, 31,537 m2 in area (3.1 ha). These swamps form on deceptively steep slopes. Median minimum swamp slope is 6.2%. The funnel-shaped valleys produce effective constrictions behind which alluvial materials and peat can accumulate, resulting in valley fills forming on relatively steep slopes.

 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. This project was also partly funded by an ARC Linkage Grant (LP130100120) awarded to A/Prof. Kirstie Fryirs and A/Prof. Grant Hose at Macquarie University. We thank Will Farebrother for working on this project. We thank the NSW Land and Property Information for the orthorectified aerial photographs that are used under a research-only license agreement.

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

Figure 2: THPSS of the Newnes region

Figure 2: THPSS of the Newnes region

Figure 3: THPSS of the Blue Mountains region

Figure 3: THPSS of the Blue Mountains region

Figure 4: THPSS of the Budderoo region

Figure 4: THPSS of the Budderoo region

Figure 5: THPSS of the Woronora region

Figure 5: THPSS of the Woronora region

Fig 6 - Gosford swamps map

Figure 6: THPSS of the Gosford region

Piccaninnie Ponds Conservation Park, South Australia

Mark Bachmann

Key words: wetland restoration, Ramsar, rising springs, drainage, hydrology

Piccaninnie Ponds Conservation Park is situated 30 km south east of Mt Gambier in South Australia. For 15-20 years after the park was proclaimed in 1969, there was considerable local interest in trying to address previous changes that had been made to the hydrology of the wetland system.

Although it was protected, reserved and supporting a diverse suite of habitats and range of resident threatened species, Piccaninnnie Ponds was far from intact from a hydrological perspective. Prior to European settlement, water that discharged from the karst, rising-spring wetlands in the system flowed eastward across the State border into the Glenelg River Estuary, in far South West Victoria.

This is how the system remained until 1906, when the first of several attempts to drain the wetlands of Piccaninnie Ponds directly to the sea occurred. What ensued was a turbulent 9 year period during which the fishermen successfully lobbied to have the creek re-directed to the Glenelg River in 1915; a step which was ultimately unpopular with affected landholders and resulted in an alternative flow path again being cut to the sea two years later in 1917. Subsequent ad hoc drainage and development of portions of the wetland system continued and by the time the Piccaninnie Ponds Conservatioon Park was proclaimed in 1969, a new main artificial outlet drained the ponds directly to the sea.

The first attempts at advocacy to restore environmental flows to the Glenelg River in the 1970s and 80s to counter this long-term drying trend in the Park were unsuccessful, until the concept was revisited and a series of steps undertaken, starting in 2001, to achieve hydrological restoration. These steps culminated in the following actions.

 Fig. 1 – Stage 1 weir and fishway under construction in 2006.

Fig. 1,  Stage 1 weir and fishway under construction in 2006.

Actions taken to correct hydrology

  1. 2006 – Stage 1 weir and fishway constructed at Piccaninnie Ponds (Figure 1) regulated outflows on the artificial outlet. This had the effect of increasing inundation in a small area immediately upstream of the structure, under the direct influence of the weir pool created by the new structure, as shown in Fig 2.
  2. 2013 – The stage 2 weir and fishway upgrade (Fig 3) resulted in the structure height being lifted to increase future management flexibility, including providing the future ability to completely block outflows, should the option of re-instating the original flow path one day become a reality.

The stage 2 upgrade was completed at the same time as providing a new flow path to physically reconnect the isolated eastern and western basins at Piccaninnie Ponds. These wetlands had been separated for several decades by a combination of lower water levels, sand drift and the impact of the Piccaninnie Ponds Road. An aerial photographic view of the new flow path is shown in Fig 4.

These works within the original Conservation Park, have occurred in in a complementary way with those that have occurred in the neighbouring, newly reserved area at Pick Swamp, each contributing to the wider vision for restoration of this wetland complex.

Fig. 2. Drained condition of habitat in 2006

Fig. 2a. Drained condition of habitat upstream of the Stage 1 weir (prior to construction  in 2006).

Fig. 3. The upstream inundation and habitat change caused by the stage 1 weir, 2012.

Fig. 2b. The upstream inundation and habitat change caused by the stage 1 weir, 2012.

Results to date.

  • Increase in quality and area of available habitat for native freshwater fish, including the nationally threatened Dwarf Galaxias (Galaxiellla pusilla)
  • Protection of hydrological processes that support a wide range of other threatened species, from a number of taxonomic groups
  • A positive trajectory of change in the distribution of wetland habitats in the vicinity of the works (increased aquatic habitat and reversal of a drying trend that was causing terrestrialisation of vegetation communities)
  • Re-establishment of connectivity between the western and eastern wetlands in the Park for the first time in several decades
Figure 4 – The lifted and redesigned stage 2 weir and fishway on the main artificial outlet at Piccaninnie Ponds – upon completion in 2013.

Fig. 3. The lifted and redesigned stage 2 weir and fishway on the main artificial outlet at Piccaninnie Ponds – upon completion in 2013.

Fig 5a. Piccaninnie

Fig. 4a. Before works – in January 2003

Figure 5 – TOP – Before works image: January 2003. BOTTOM – Post-construction/restoration image: January 2014.

Fig, 4b. After construction/restoration – in January 2014.

Future directions. The works and outcomes described here were delivered by staff working for the South Australian Department of Environment, Water and Natural Resources (DEWNR)

  • Ongoing management of the works and associated ecological monitoring in Piccaninnie Ponds Conservation Park is managed by DEWNR
  • Nature Glenelg Trust staff continue to provide specialist ecological advice and monitoring for the site when required by the site manager, DEWNR

Acknowledgements. The outcomes of the restoration project described can be attributed to a wide range of people who, in addition to the author (see current contact details below), worked at the South Australian Department of Environment, Water and Natural Resources during the period described. DEWNR project ecologists overseeing the works described here include Ben Taylor (stage 1 weir) and Steve Clarke (stage 2 weir and associated works).

The project was generously funded and supported by a range of different grants and programs administered by the South Australian Government, Australian Government and the South East Natural Resources Management Board.

Contact. Mark Bachmann. Nature Glenelg Trust, PO Box 2177, Mt Gambier, SA 5290 Australia; Tel +61 (0)8 8797 8181; Mob+61 (0) 421 97 8181; Email: mark.bachmann@natureglenelg.org.au Web| www.natureglenelg.org.au

See also:

Bradys Swamp EMR short summary

Long Swamp EMR short summary

Victorian Northern Plains Grasslands Protected Area Network: formation and future management

Nathan Wong

Key words: ecosystem decline, conservation planning, grassland restoration, threatened species

Building the network. Since the early 1990s Trust for Nature (Victoria) (TfN) in partnership with State and Federal government agencies and local land owners have been working to protect, restore and improve the condition and extent of Grasslands in the Victorian Riverina. This critically endangered ecosystem has been degraded, fragmented, and cleared over the past 200 years by a range of impacts largely associated with the exploitation of these areas for agricultural production. This use has resulted in the loss of over 95% of the original grassland extent in Victoria and the degradation of all remaining remnants.

The first major achievement of this program occurred in June 1997 when Trust for Nature acquired the 1277 ha ‘Davies’ property following many years of negotiations. This land was transferred to the Crown in April 1999 to form the Grassland section of what is now Terrick Terrick National Park. Since this initial acquisition a significant number of purchases have been added to the public estate with the support of both State and Federal National Reserve Systems Programs. These additions have resulted in Terrick Terrick National Park now covering over 3334ha (Table 1) and the establishment of Bael Bael Grasslands NCR during 2010 and 2011 which now covers 3119ha.

Running concurrently with this increase in the public estate has been a program to build and secure private land under conservation covenant as well as Trust for Nature establishing a number of reserves to build its private reserve network in the Victorian Riverina. These efforts have resulted in the addition of 2804ha owned by Trust for Nature, including Glassons Grassland Reserve (2001), Kinypanial (1999), Korrak Korrak (2001), Wanderers Plain (2009-2010) and 1036ha of private land protected under conservation covenant.

As a result of these efforts the area of grasslands within the Protected Area Network in the Victorian Riverine Plains has grown from virtually nothing in the mid-1990s, to in excess of 10,000ha and continues to expand.

OLYMPUS DIGITAL CAMERA

Fig 1. Very high quality Northern Plains Grasslands in Spring, note the inter-tussock spaces and diversity of flowering herbs (Photo: Nathan Wong).

Table 1. Acquisitions that have resulted in Terrick Terrick National Park, now covering over 3334ha.

Table 1

Current remnant condition. Whilst these grasslands are the best examples of the remaining ecosystem and protected under State and Federal government legislation, all of them have been degraded by past land-use. Therefore the need to not only protect but restore them is critical to the successful management of these systems in-perpetuity. Despite this past loss of a range of grazing-sensitive plant species many still persist in small isolated populations across the reserve network. Management of grazing, when it is applied, to ensure that continued losses do not occur whilst maintaining biodiversity values is one of the key aims of management. As a result of loss of quality, quantity and fragmentation of habitats, a range of important faunal species have also historically declined (Figs 2 & 3).

Need for management and restoration. There is great potential for management regimes to manipulate the composition of grasslands to enhance the likelihood of restoration success. Restoration of a range of grazing sensitive plant species which now either regionally extinct or remain in small isolated population will almost certainly require changes to grazing regimes, reintroduction of fire regimes and species reintroductions to ensure viable populations. Reintroducing faunal species will also require attention to connectivity and habitat availability issues in this context as many are dependent on the existence of large, interconnected territories e.g. Hooded Scaly-foot (Pygopus schraderi).

The Northern Plains Grasslands Protected Area Network: Strategic Operational Plan (SOP) is a landscape-scale strategic operational plan for the conservation management of the Northern Plains Grassland community within Victoria’s Protected Area Network, developed by the Northern Plains Technical Advisory Group in 2011. This Operational Plan now guides TfN and Parks Victoria in the implementation of an adaptive management plan for the landscape. This plan aims to establish and implement a restoration program across the public and private protected areas and is a marked shift from the previous management intent of maintenance of the system.

Fig 2. The area, particularly the Patho Plains and Lower Avoca, provide important habitat for the persistence of the Plains-wanderer (Photo David Baker-Gabb).

Fig 2. The northern plains grasslands, particularly the Patho Plains and Lower Avoca, provide important habitat for the persistence of the Plains-wanderer (Photo David Baker-Gabb).

Strategies for management and restoration. There are two main strategies that are being implemented. The first involves the extension of protected areas through a range of mechanisms; and the second involves active management to restore habitat quality and diversity to the extent possible.

Extent. Expansion of the current approach of reserve acquisition and covenanting that has been undertaken by the range of partners is likely to able to target and establish large areas (20,000+ ha) in the Lower Avoca and Patho Plains landscape. Both these areas are high priorities for Trust for Nature and form significant sections of the Trust for Nature’s Western Riverina Focal Landscape. The Patho Plains is significant as it is an Important Bird Area and a focus of Birdlife Australia to ensure the long term persistence of the Plains-wanderer (Pedionomus torquatus). The Lower Avoca also provides important habitat for the Plains-wanderer (Draft National Recovery Plan) and is one of the main population centres for Hooded Scaly-foot in Victoria.

Diversity. The increase of diversity and quality of these systems requires direct intervention in management as well as the introduction and establishment of the many rare and regionally extinct species from the system.

Plant species: Over the past decade, TfN and others have successfully trialled the reintroduction of a number of threatened and common plant species through hand sowing seed into grasslands. These species include: Hoary Sunray (Leucochrysum molle), Leafless Bluebush (Mairena aphylla), Rohlarch’s Bluebush (Maireana rohlarchii), Bladder Saltbush (Atriplex vesicaria), Plains Everlasting (Chrysocephalum sp. 1), Beauty Buttons (Leptorhynchos tetrachaetus), Small-flower Goodenia (Goodenia pusilliflora), Minnie Daisy (Minuria leptophylla) and a range of Wallaby species (Rytidosperma spp.) and Spear Grasses (Austrostipa spp.).

Animal species: Local habitat variability for a range of fauna has been achieved through the modification of grazing regimes and the introduction of burning regimes at a range of sites. This work aims to maximise niches and thus opportunities for a broad range of species.

Fig 3. Hooded Scaly-foot adult by Geoff BrownCOMP

Fig 3. Hooded Scaly-foot adult, a critically endangered legless lizard that occurs in the Northern Plains Grasslands, preferring habitat much like the Plains-wanderer. Photo: Geoff Brown.

Table 2.  Triggers required for various grazing and other management regimes to maintain appropriate intertussock spaces in Northern Plains Grasslands

Table2

Monitoring. The SOP includes a method for rapid assessment of habitat and functional composition of sites to support decision making and track habitat change over time. This is stratified by soil type as grazing and habitat values and floristic communities vary between soil types within the grassland mosaic. Triggers for action or management bounds have been set based on the structure of inter-tussock spaces on red soils. These have been established using the “Golf ball” method which calculates a golf ball score by randomly dropping 18 golf balls into a 1m x 1m quadrat and then establishing a count based on the visibility of the golf balls (>90% visible = 1, 90%-30% visible = 0.5, <30% visible = 0). For red soil grasslands the aim is to maintain the inter-tussock spacing within a golf ball range of 13-16 using the range of tools identified in Table 2. When a paddock reaches a golf ball score of 16 and it is being grazed, stock are to be removed. When the paddock reaches a score of 13 they are then to be reintroduced, within the bounds of the regime that is to be applied.

Additional to this there has also been collection of data in relation to the functional composition of sites with golf ball quadrats also assessed for the presence of a range of functional groups including Native C4 grasses, Native C3 Grasses, Exotic annual grasses, Exotic Perennial Grasses, Native forbs, Exotic Forbs, Native Shrubs, Moss cover, Other Crytptograms (i.e. Lichen, Algae, Liverworts), Bare Ground and Litter. At all these sites photos are also taken of each quadrat with and without golf balls and a landscape photo is also taken.

The capturing of these data and the region wide approach across both public and private areas will increase our knowledge of how to manage and restore these important sites as well as track progress of management actions and their effectiveness in providing protected areas for a range of threatened species.

Acknowledgements. A wide range of partners and individuals are involved in the protection of the Northern Plains Grassland and the development of the Northern Plains Strategic Operations Plan including Parks Victoria, Department of Environment, Land, Water & Planning (DELWP), La Trobe University, Charles Sturt University, Arthur Rylah Institute for Environmental Research, North Central Catchment Management Authority, Northern Plains Conservation Management Network, Elanus Consulting and Blue Devil Consulting.

Contact: Nathan Wong, Conservation Planning Advisor, Trust for Nature (Level 5, 379 Collins Street, Melbourne VIC 3000, Australia;Tel: +61 (0)3 8631 5888; Freecall: 1800 99 99 33; Mob 0458 965 329;Email: nathanw@tfn.org.au, www.trustfornature.org.au).

 

 

 

Defining reference communities for ecological restoration of Monjebup North Reserve in Gondwana Link

Justin Jonson

Key words: reconstruction; reference ecosystem; planning; ecosystem assemblage; monitoring

Introduction. Bush Heritage Australia’s (BHA) Monjebup North Reserve is a property that directly contributes to the conservation, restoration and connectivity objectives of Gondwana Link – one of Australia’s leading landscape scale restoration initiatives. Building on a solid history of revegetation projects implemented by collaborators from Greening Australia and individual practioners, the BHA management team initiated and funded a $40K Ecological Restoration Planning Project for 400 hectares of marginal farmland in need of restoration.

The specific aim of the Monjebup North Ecological Restoration Project was to 1) plan and 2) implement a ‘five star’ ecological restoration project as defined by the Gondwana Link Restoration Standards. Overarching goals included the re-establishment of vegetation assemblages consistent with the surrounding mosaic of plant communities, with a specific focus on local fauna and the restoration of habitat conditions to support their populations.

Figure 1: Map showing GPS locations of soil auger sampling locations.

Figure 1: Map showing GPS locations of soil auger sampling locations.

Planning and identification of reference communities for restoration of cleared land. The Monjebup North Ecological Restoration Project began with a third party consultancy contract to develop the Monjebup North Ecological Restoration Plan. This work began with the collection of detailed field data, including 120 soil survey pits collected to define the extent and boundaries between different soil-landform units occurring on the site (Fig.1). In the absence of previously defined and/or published information on local plant communities, an additional vegetation survey and report, The Vegetation of Monjebup North, was developed, which included 36 vegetation survey sites widely distributed across the surrounding vegetation (Fig.2). A total of 10 primary vegetation associations were defined within remnant vegetation on and around the site from this work (Fig.3). Additional soil survey pits were established within these defined plant communities to develop relationships between observed vegetation associations and soil-landform units. Cross referencing this information to the 400 hectare area of cleared land resulted in the delineation of seven core reference communities to guide the restoration project. These restoration communities ranged from Banksia media and Eucalyptus pluricaulis Mallee Scrub associations on spongelitic clay soils, to Eucalyptus occidentalis (Yate) Swamp Woodland associations located in low-lying areas where perched ephemeral swamps exist.

Figure 2: Map showing GPS locations of flora survey sampling sites.

Figure 2: Map showing GPS locations of flora survey sampling sites.

Figure 3: Output map of dominant vegetation associations at Monjebup North Reserve.

Figure 3: Output map of dominant vegetation associations at Monjebup North Reserve.

Figure 4: Mosaic of plant communities replanted at Monjebup North in 2012 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Figure 4: Mosaic of plant communities replanted at Monjebup North in 2012 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Figure 5: Mosaic of plant communities replanted at Monjebup North in 2013 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Figure 5: Mosaic of plant communities replanted at Monjebup North in 2013 using direct seeding and hand planted seedlings. A tractor fitted with GPS unit enables real time seeding passes, as shown on the map.

Seed sourcing. Seed from approximately 119 species were collected on and around the site for the restoration works. Seed collections for some species were collected from a number of geographically separate sub-populations, however these were never located further than 10 kilometers from site. Collections were made from at least 20 individuals for each species, and preference was made in collecting from populations which had 200+ individuals.

The primary on-ground works were initiated across four years from 2012 to 2015, starting with a 100 ha project area in 2012 (Fig.4), and a 140 ha area in the following year (Fig.5), both by Threshold Environmental Pty Ltd. A combination of direct seeding and hand planted seedlings treatments were employed, where seed mixes were developed to achieve the bulk of plant recruitment across each of the soil-land form units, and nursery grown seedlings were planted by hand for species found to be difficult to establish from direct seeding or for which stocking densities were to be more closely controlled. This work involved 13 communities and 148 species.

A number of innovative operational treatments were employed. These included grading 5 kilometers of contour banks and spreading chipped vegetation and seed pods, and 180 in situ burning patches where branch and seed material from fire-responsive serotinous species were piled and burned (Fig.6 before, Fig.7 after). Seedlings for rare, high nectar producing plant species were also planted in 203 discrete ‘node’ configurations. Habitat debris piles made of on-site stone and large branch materials were also constructed at 16 locations across the 2012 project areas.

Fig.6 In situ burning of serotinous branch and seed material

Figure 7: Photo of Dryandra nervosa juvenile plants establishing from one of the in situ burn pile locations. Other species used for this technique included Dryandra cirsioides, Dryandra drummondii, Hakea pandanicarpa, Isopogon buxifolius, and Hakea corymbosa.

Figure 7: Photo of Dryandra nervosa juvenile plants establishing from one of the in situ burn pile locations. Other species used for this technique included Dryandra cirsioides, Dryandra drummondii, Hakea pandanicarpa, Isopogon buxifolius, and Hakea corymbosa.

Monitoring. Monitoring plots were established to evaluate the direct seeded revegetation, as presented in the Project Planting and Monitoring Report 2012-2013. Fauna monitoring has also been undertaken by BHA using pit fall traps, LFA soil records, and bird minute surveys.

Results to date. Monitoring collected from post establishment plots in from the 2012 and 2013 areas (2 years after seeding) showed initial establishment of 2.4 million trees and shrubs from the direct seeding (Fig.8 and Fig.9). Results of faunal monitoring are yet to be reported, but monitoring at the site for vegetation and faunal is ongoing.

Figure 8: Graphic representation of monitoring results from 2012 and 2013 operational programs showing scaled up plant counts across the plant community systems targeted for reconstruction.

Figure 8: Graphic representation of monitoring results from 2012 and 2013 operational programs showing scaled up plant counts across the plant community systems targeted for reconstruction.

Figure 9: Photo showing 3 year old establishment and growth of a Banksia media/Eucalyptus falcata Mallee shrub plant community with granitic soil influence from the 2012 Monjebup North restoration project.

Figure 9: Photo showing 3 year old establishment and growth of a Banksia media/Eucalyptus falcata Mallee shrub plant community with granitic soil influence from the 2012 Monjebup North restoration project.

Lessons learned and future directions. The decision to develop a restoration plan in advance of undertaking any on-ground works was a key component contributing to the success of the project to date. Sufficient lead time for contracted restoration practitioners to prepare (>12 months) was also a key contributor to the success of the delivery. Direct collaboration with seed collectors with extensive local knowledge also greatly benefited project inputs and outcomes.

Stakeholders and Funding bodies. This project is a part of the Gondwana Link initiative. Major funding for the project was provided by Bush Heritage Australia and Southcoast Natural Resource Management Inc., via the Federal Government’s National Landcare Program and the Biodiversity Fund. This work would not have been possible without Bush Heritage Australia, who purchased and continue to manage the Monjebup North Reserve as a part of their larger conservation estate. Threshold Environmental are grateful for the opportunity to be engaged in these works.

Contact information. Justin Jonson, Managing Director, Threshold Environmental, PO BOX 1124, ALBANY WA 6330 +61 427 190 465; jjonson@thresholdenvironmental.com.au

See also EMR summary Peniup

 Watch video: Justin Jonson 2014 AABR presentation

Subtropical rainforest restoration at the Rous Water Rainforest Reserve, Rocky Creek Dam, 1983 – 2016

Key words: Lowland subtropical rainforest, ecosystem reconstruction, drinking water catchment, continual improvement process.

Introduction. Rous Water is actively engaged in ecosystem reconstruction within the drinking water catchment areas it manages on behalf of the community. The aim of these activities is to improve the functioning of essential natural processes that sustain water quality. The methodology used for rainforest restoration by Rous Water has evolved over time through an ‘adaptive management’ process at Rocky Creek Dam. This adaptive management approach has demonstrated that effective large scale sub-tropical regeneration at Rocky Creek Dam is achieved through complete removal of competing plants. The technique has become known as the Woodford Method and is now being applied at other Rous Water restoration sites.

The Rous Water Rainforest Reserve at Rocky Creek Dam is set in the northern headwaters of the Richmond River catchment, on the southern rim of the Tweed shield volcano. Basalt flows from the volcano have produced nutrient rich Red Ferrosol that supported diverse sub-tropical rainforest ecosystems across the region, until the rainforest was largely cleared for agriculture in the late 19th century. The Rocky Creek Dam site is adjacent to the Big Scrub Flora Reserve, the largest remaining remnant subtropical rainforest in the region. This reserve acts as a reference site for the restoration project (Fig 1).

Figure 1. Detail of the regeneration areas at Rocky Creek Dam, showing the areas treated and the year of the initial works

Figure 1. Detail of the regeneration areas at Rocky Creek Dam, showing the areas treated and the year of the initial works

Clearing of land in the vicinity of Rocky Creek Dam by early settlers commenced in the 1890s, with the cleared lands used for the establishment of dairy farms and a sawmill. In 1949, following acquisition of the site by Rous County Council (now Rous Water) for the construction of a water supply dam, this former farmland had reverted to weedy regrowth characterised by a mosaic of native/exotic grass, Lantana (Lantana camara) and Camphor Laurel (Cinnamomum camphora) which supressed any expansion or recovery of scattered rainforest remnants. Transformation of the site commenced in 1983 when Rous Water became actively engaged in ecosystem recovery by systematically removing weeds that suppressed rainforest regeneration, a practice that continues today.

Rainforest restoration methods. The practices and management tools used in rainforest restoration at the site have been previously described by Woodford (2000) and Sanger et al. (2008). The work method typically involves the systematic poisoning and slashing of weeds to promote recruitment of rainforest plants from the soil seed bank and then to facilitate the growth of suppressed rainforest plants, providing a structural framework for further seed dispersal by wind and, particularly, flying frugivores and thus further colonisation by later phase rainforest trees.

Since 1983, an area of approximately 70 ha has been progressively treated in 1-2 ha blocks using this methodology (refer Fig 1), with progressively diminishing amounts of follow-up treatment needing to be conducted in the treated areas over subsequent years to secure successional progression of the rainforest species.

Use of this method means that, due to recruitment from the seed bank and the use of stags (from dead camphor laurel) as perches for seed dispersing birds, very limited planting has been required on the site. This has preserved the genetic integrity of the Big Scrub in this location.

Results. A total of approximately 70 hectares of weed dominated regrowth has been treated at the Rous Water Rainforest Reserve since commencement in 1983 (Figure 1). This is approximately 35 ha since the report previously published in 2000 and represents approximately 30 % of the Rous Water property at Rocky Creek Dam.

This progressive treatment of compartments of weedy regrowth at Rocky Creek Dam has continued to lead to rapid canopy closure by shorter lived pioneer and early secondary tree species, with a gradual progression to higher proportions of later secondary and primary species with increasing time since treatment. All tree species that are listed as occurring in the reference site are not only now present in the restoration area, but informal observations suggest that most, if not all, are increasing in abundance over time (Figs 2-6)

Figure 2. Treated regrowth at the Rous Water Rainforest Reserve, Rocky Creek Dam After 1 year (foreground)

Figure 2. Typical regeneration of rainforest species 1 year after Lantana removal at the Rous Water Rainforest Reserve, Rocky Creek Dam (foreground).

Figure 3. Same photopoint after 6 years

Figure 3. Typical recovery after 6 years

Figure 4. Same photopoint after 12 years

Figure 4. Typical recovery after 12 years

Figure 5. Same scenario after 20 years

Figure 5. typical recovery after 20 years

Figure 6. After 30 years

Figure 6. Typical recovery after 30 years

The structure of the older treated regrowth areas sites appears to be converging on rainforest conditions, as noted by Kanowski & Catterall (2007). Thackway & Specht (2015) depict how 25 ha of systematically treated compartments that were covered almost entirely with lantana are progressing back towards the original Lowland Subtropical Rainforest’s composition, structure and ecological function (Fig 7). Overall the vegetation status in this area was assessed at between 85% and 90% of its pre-clearing status.

This process is, at its oldest 33 years old and in some locations much younger. So it is clear that the development of the subtropical vegetation still has many decades, possibly centuries, to go, before it approaches the composition, structural and habitat characteristics of a primary forest. Notwithstanding the large areas of natural regrowth that are yet to be worked, it is evident that a large proportion of the assisted regeneration areas progressively worked by Rous over the past 33 years now requires only a low level of ongoing maintenance. This shows that these sites are maturing over time and have largely reached a self-organising state, and in the fullness of time will achieve a high degree of similarity to the reference state.  (A recovery wheel for one subsite is shown in Fig 8)

Fig 7, Thackway fig rocky creek dam1

Figure 7. Assessment of change in indicators of vegetation condition in a 25 ha area. This depicts the degree of recoveery of Lowland Subtropical Rainforest found at Rocky Creek Dam, Big Scrub, NSW against a pre-clearing reference. (Graph reproduced with permission. The method used to generate the graph is described in Thackway, R. and Specht, A., (2015). Synthesising the effects of land use on natural and managed landscapes. Science of the Total Environment. 526:136–152 doi:10.1016/j.scitotenv.2015.04.070. ) Condition indices for transition Phase 4 were derived from prior reports including Sanger et al. 2008 and Woodford 2000. Metadata can be viewed at http://portal.tern.org.au/big-scrub-rocky-queensland-brisbane/16908 .

Lessons learned. Using this method of harnessing the natural resilience processes of the rainforest, we have been able to progress the recovery of an important water catchment area, restoring very high biodiversity conservation values in a landscape where rainforest was, and remains, in serious decline., The ability of the high resilience sites at Rocky Creek Dam to respond to the Woodford Method is clearly demonstrated, but there is ample evidence that application of this and similar resilience-based rainforest restoration methods can harnessed resilience at other sites in the Big Scrub that are at greater distances from remnants.

Figure 8. Distribution of management intensity classes across the Rous Water Rainforest Reserve at Rocky Creek Dam.

Figure 8. Distribution of management intensity classes across the Rous Water Rainforest Reserve at Rocky Creek Dam. (Legend for this map is in Appendix 1)

Current work and future directions. Work continues at the site and management is supportive of-site evaluation to assess the extent to which the treated areas are undergoing successional development using a range of available assessment tools.

To assist future planning, and in order to address the issue of how to best estimate and plan for restoration works and associated costs, Rous Water has adapted the methodology developed on the Tweed-Byron Bush Futures Project, where each restoration site/area was assigned a Management Intensity Class (MIC) based on a generalised assessment of site condition, weed composition and cover and other management requirements. (Fig 8) The MIC describes the frequency of restoration work required to restore the site to a minimal maintenance level and how many years this would take to achieve. The MIC aims to describe the extent of management intervention necessary to restore the site to a minimal maintenance level. For this analysis this equates to the establishment of a self sustaining sub-tropical rainforest buffer zone. Each management intensity class is associated with a particular restoration trajectory/cost per hectare, based on visitation frequency by a standard 3 person team and expressed in terms of number of visits required to control / manage weeds. Appendix 1 below shows details of the MIC classification, showing for each class, relevant site criteria, and the estimated level of bush regeneration resources required to bring each class to a low maintenance level.

Contact: Anthony Acret, Catchment Assets Manager,  Rous Water. Tel: +61 (0) 2 6623 3800, Email: anthony.acret@rouswater.nsw.gov.au

Rocky Creek Dam recovery wheel adjacent to Forest Edge

Appendix 1. Legend for Management intensity classes used in Fig 8. (From Tweed-Byron Bush Futures)

Appendix 1. Legend for Management intensity classes used in Fig 8.

Case Study: Restoring the Lost Shellfish Reefs of Port Phillip Bay

Simon Branigan

Key words: shellfish reefs, native flat oyster, blue mussel, ecological restoration, marine ecosystem

Background. Globally, shellfish reefs are the most threatened marine habitat on earth.  Research published by The Nature Conservancy documented that that over 85% of shellfish reefs have been lost from coastal areas worldwide, with 99% of shellfish reefs ‘functionally extinct’ in Australian coastal waters, including within Port Phillip Bay (Shellfish Reefs at Risk Report).

This dramatic loss of shellfish reef habitat in Port Phillip Bay had occurred by the mid to late 20th century, caused by over-harvesting through destructive dredge fishing, further compounded by pollution, predation and disease in later years.

In an Australian first, The Nature Conservancy Australia (TNC) are part of a research partnership that are trialling different approaches to restoring Port Phillip Bay’s lost shellfish reefs (video link).

Shellfish reefs are intertidal or subtidal three-dimensional habitats formed by oysters and/or mussels at high densities. Shellfish reefs can vary in appearance depending on the dominant reef-forming species. There are many common attributes of shellfish reefs including:

  • They provide habitat and refuge for other species including sessile and mobile organisms, supporting high levels of species diversity and unique assemblages;
  • They can accrete dead shell material such that the reef grows in size and mass over time;
  • They provide food for other organisms, either when consumed directly or through the species assemblages they support.
Figure 1. Clumping native Flat Oysters at 9ft Bank in Port Phillip Bay

Figure 1. Clumping native Flat Oysters at 9ft Bank in Port Phillip Bay

Figure 2. Remnant Oyster Reef in Georges Bay, St Helens, Tasmania. (Photo: Chris Gillies)

Figure 2. Remnant Oyster Reef in Georges Bay, St Helens, Tasmania. (Photo: Chris Gillies)

Restoring the Lost Shellfish Reefs of Port Phillip Bay. A three-year trial was established in late March 2015 to investigate the following research questions:

  • Can the oysters simply grow on the bottom or do they need a rubble base?
  • Can oysters be deployed at a young age and survive, or is it more beneficial for a grow-out on aquaculture leases to gain a ‘headstart’?
  • At what densities do we need to deploy mature mussels? (i.e. Can they create mussel beds naturally on the sediment or require substrate?)

 Reference ecosystem. Historical information and relictual evidence shows that the shellfish reefs of Port Phillip Bay were subtidal with the dominant species being native flat oyster (Ostrea angasi) and Blue Mussel (Mytilus (edulis) galloprovincialis). Healthy reference sites for such reefs are very limited in Southern Australia. Within Port Phillip Bay the only site found so far is a dispersed clumping reef called 9ft Bank (Fig 1). A remnant shellfish reef also occurs in Georges Bay, off St Helens in Tasmania (Fig 2). Further research is planned for the Tasmanian site to complete a biological assessment to inform long-term restoration targets and reef design at Port Phillip Bay and other future sites in the region.

Locations of the restoration trials: The intent is to conduct restoration trials in three locations within Port Phillip Bay, although currently works are occurring at only two sites: Wilson Spit (Outer Geelong Harbour) and Margarets Reef (Hobsons Bay) (Fig 3). These are both old shellfish reefs that are largely dead and covered by sediment (Fig 4). The depth range is between 6 to 8 metres depth with Wilson Spit being a silty mud bottom and Margarets Reef sand.

Figure 3. Port Phillip Bay Shellfish Reef Restoration sites.

Figure 3. Port Phillip Bay Shellfish Reef Restoration sites.

Figure 4. Relictual evidence of previous oyster reef at Wilson Spit restoration site. (Photo: Paul Hamer).

Figure 4. Relictual evidence of previous oyster reef at Wilson Spit restoration site. (Photo: Paul Hamer).

Works Undertaken. As Port Phillip Bay is both reef substrate- and recruitment-limited a reconstruction approach (involving rebuilding substrates and reintroducing oysters and mussels) is a necessary starting point for the restoration, with the longer term expectation of natural colonisation.

The trial has involved the deployment of a total of 6 tonnes of limestone marl substrate in a patchwork of 1m x 1m plots at both sites. Native flat oysters are being raised at the Victorian Shellfish Hatchery and their larvae settled on recycled scallop shells (called cultch) (Fig 5). The larvae are then left for a 3-6 month period on an aquaculture lease before being deployed onto the substrate base (Fig 6). To date over 20,000 live oysters have been deployed to seed the reefs. In addition, over 6 tonnes of blue mussel have also been deployed at different densities and in 3 x 3m plots (Fig 7).

Figure 5. Cultch spat growing out at the Bates Point Aquaculture Lease. (Photo: Ben Cleveland)

Figure 5. Cultch spat growing out at the Bates Point Aquaculture Lease. (Photo: Ben Cleveland)

Figure 6. Limestone rubble base with cultch spat. (Photo: Paul Hamer)

Figure 6. Limestone rubble base with cultch spat. (Photo: Paul Hamer)

Figure 7. Deployed mussel bed at Margarets Reef. (Photo: Paul Hamer)

Figure 7. Deployed mussel bed at Margarets Reef. (Photo: Paul Hamer)

 Monitoring Methodology. The University of Melbourne are contracted to lead the monitoring in Stage 1 of the restoration trial. Baseline sampling was conducted of the trial pre-deployment (trial layout is shown in Fig 8) and subsequent monitoring to be carried out 6 months and 12 months after deployment. Monitoring includes measuring:

  • Oyster survival per shell on the various substrate treatments
  • Oyster growth on the various substrate treatments
  • Mussel survival (inner cores only) and mussel growth as well as shell cover and predator density
  • Baseline community sampling (pre-deployment) of mobile fish, cryptic fish, mobile invertebrates, benthic biota and benthic substrate.
Figure 8. An example of the oyster reef experimental design at the Margaret Reef site.

Figure 8. An example of the oyster reef experimental design at the Margaret Reef site.

Lessons Learned and Future Directions. Early monitoring results from both sites show that oyster spat survival is greater if deployed on a rubble base than directly to the seabed, with cultch loss high on sand, due to burial. Oysters grew on average five times as fast on rubble than sand over winter. We conclude from this that elevation is important for both the survival and growth of oysters.

For the mussels the highest density treatment had the highest mortality at both sites, suggesting that the low density treatment improves survival and may be the most cost effective approach.

The most abundant predator was the native Eleven-arm Seastar (Coscinasterias calamaria).

We consider that scale is important in helping to minimise early losses and this hypothesis will be tested in the second stage of the trail. Planning is in place to scale-up the trial to 20 x 20m plots in late 2016, with a mixed-species approach, combining mussels and oysters rather than having separate treatments. Elevation through large and small limestone rubble will also be tested, integrated with recycled shells sourced from restaurants and wholesalers.

Stakeholders and Funding. The Restoring the Lost Shellfish Reefs of Port Phillip Bay Project is a key element of The Nature Conservancy Australia’s Great Southern Seascapes Program and delivered in partnership with the Victorian Government (Fisheries Victoria) and Albert Park Yachting and Angling Club. All partners have contributed funding towards the project and continue to fundraise.

Contact. Simon Branigan, Estuaries Conservation Coordinator, The Nature Conservancy Australia, Suite 2.01, The 60L Green Building, 60 Leicester Street, Carlton, VIC 3053, Australia. Tel: 0409087278. Email: simon.branigan@tnc.org

WATCH FIRST VIDEO: Shellfish reef restoration in Port Phillip Bay

WATCH SECOND VIDEO: Trialling shellfish reef restoration techiques for potential application across Australia

Recovering biodiversity at Trust for Nature’s Neds Corner Station, Victoria

Doug Robinson, Deanna Marshall, Peter Barnes and Colleen Barnes

Key words. Private conservation area, natural regeneration, ecological restoration, rabbit control.

Introduction. Neds Corner Station is Victoria’s largest private conservation property. This 30,000 hectare ex-sheep and cattle station was purchased for nature conservation by Trust for Nature (Victoria) in 2002.

The property occupies the driest area of the state with an average annual rainfall of only 250 mm. As such, it has strong ecological links to the arid regions of Australia and Australia’s rangelands. Neds Corner sits strategically at the hub of an extensive network of public and private conservation lands bordering or close to the Murray River in Victoria, New South Wales and South Australia. The reserve is bordered on three sides by the Murray Sunset National Park and borders frontages along the Murray River and associated anabranches for more than thirty kilometres, where the River Red Gum (Eucalyptus camaldulensis) dominated riparian zone connects with Chenopod Shrublands, Semi-arid Chenopod Woodlands and Chenopod Mallee Woodlands. Trust for Nature’s restoration efforts are targeted at restoring woodland connectivity across the property to improve habitat extent and condition for woodland and mallee plants and animals, including the nationally threatened Regent Parrot (Polytelis anthopeplus). A biodiversity survey in 2011 found 884 native species at Neds Corner Station, including 6 threatened birds and animals, 77 threatened plants, and 21 species new to science. Trust for Nature continues to find new records for the property.

Fig 1 Neds 2003

Fig. 1. Highly degraded area (near watering points) in 2003 just after Trust purchased the property.

 

Fig 2 Neds 2011

Fig. 2. Same photopoint in 2014 showing extensive natural regeneration of Low Chenopod Shrubland after removal of livestock and extensive treatment of rabbits.

 

Planning for recovery. In 2002, when Trust for Nature first took on the property, the land was severely degraded from continuous over grazing by stock, rabbits and native herbivores; weed infestations; historic clearing of extensive areas of woodland for firewood and forage; and lack of flooding. Native vegetation was sparse over much of the property, soil erosion was extensive and the floodplain and semi-arid woodlands were all showing signs of extreme stress.

In the early years of ownership, management focussed on addressing the most obvious of these threats, with a focus on rabbit control and weed control. In 2010, with funding support from The Nature Conservancy, Trust for Nature prepared a Conservation Action Plan for the reserve, using the Open Standards for Conservation process, and a subsequent management plan. These planning documents identified the key biodiversity values on the reserve, the major threats to these values and the strategies to reduce threats and improve condition to achieve agreed ecological goals.Fig 6 Neds

Fig. 3. Dune Wattle (Acacia ligulata) natural regeneration after cropping was discontinued.

Fig 7 Neds

 Fig 4. Hop Bush (Dodonaea viscosa) natural regeneration after cropping ceased.

Works undertaken. Trust for Nature’s first action was to remove the livestock to allow the regeneration and growth of native vegetation. Stock fencing was decommissioned to enable free movement of native fauna, and new exclosure fencing to protect sites of cultural and ecological significance were also constructed. Major efforts were made to reduce rabbit numbers through the use of warren ripping, fumigation and 1080 baiting across the property. To date, over 20,000 warrens have been treated. Direct seeding and tubestock planting in the Semi-arid Woodland areas of the property have been continuous, with the cessation of a cropping licence, over 500 ha direct seeded in one year as part of an Australian Government funded project. In partnership with the Mallee Catchment Management Authority, environmental water allocations have been used to inundate areas of Neds Corner, providing a vital lifeline to many of the plants and animals that inhabit the riverine billabongs and floodplain forests. Artificial water points and superfluous tracks have been closed. Targeted fox and other feral animal programs are continuous.

Fig 3 Neds 2003

Fig 5. Highly degraded ‘Pine paddock’ in 2003 just after the Trust purchased the property.

Fig 4 Neds 2011

Fig 6. Pine paddock from same photopoint in n2014 after exclosure fencing, rabbit control and extensive direct seeding of trees and shrubs in 2007 (and again in 2010). The grasses all naturally regenerated.

Results. In the 14 years since domestic stock removal and the ongoing control of rabbits and weeds, there has been a dramatic increase in the cover of native vegetation, notably from natural regeneration (Figs 1-4) but also from extensive supplementary planting and direct seeding (Figs 5-8). In 2011, wide spread natural germination of Murray Pines occurred across the woodland sections of the property and Sandhill Wattle (Acacia ligulata) seedlings were observed on one rise where no parent plant was known to occur, indicating a viable seed bank may exist. The vulnerable Darling Lilies (Crinum flaccidum) continue to extend their range, given favourable weather conditions and the continuous control of herbaceous threats to the extent required to ensure adequate recruitment of these key flora species. Bird surveys undertaken for one of the targeted projects within Neds Corner over the past 10 years show an encouraging increase in reporting rates of Brown Treecreeper (Climacteris picumnus victoriae) (>x2 increase), Chestnut-crowned Babbler (Pomatostomus ruficeps) (>x2% increase) and Red-capped Robin (Petroica goodenovii) (>x20 increase).

Fig 5 neds

Fig.7. Revegetation plantings in 2008

Fig 6 NEds 2014

Fig 8. Same revegetation planing line in 2013.

Current and future directions. Trust for Nature are due to revise their CAP and have identified the need to undertake recovery actions at a greater scale. They are currently investigating the feasibility of re-introducing some fauna species back into Neds Corner Station that haven’t been found in the region for decades, provided there is sufficient habitat to sustain them.

Acknowledgements. As a not-for-profit organisation, Trust for Nature (Victoria) relies on the generous support of many individuals, organisations and government entities. The main project partners to date include The Nature Conservancy, RE Ross Trust, Yulgilbar Foundation, Australian Government, Mallee Catchment Management Authority, Parks Victoria, Department of Environment, Land, Water & Planning, Mildura Rural City Council, Northern Mallee Region Landcare, Traditional Owners and the thousands of hours volunteers contribute to Neds Corner Station.

Contact: Doug Robinson, Conservation Science Coordinator, Trust for Nature: (Tel: +61 1800 99 99 33.) Email: dougr@tfn.org.au; www.trustfornature.org.au

Photos: Trust for Nature

 

 

 

Restoration at Numinbah Conservation Area, City of the Gold Coast, Queensland

Key Words: assisted regeneration, restoration planning, conservation

Introduction: Numinbah Conservation Area, located in the hinterland of the Gold Coast in south-east Queensland, is one of many natural areas managed by City of Gold Coast’s Natural Areas Management Unit (NAMU). The 598 ha property contains 12 Regional Ecosystems (REs) ranging from sub-tropical and dry rainforest to dry and wet sclerophyll types; and include riparian zones, steep areas, gullies and rocky outcrops. Its conservation value is heightened by the fact that it connects to other reserves including the World Heritage areas of Springbrook.

Condition ranges from large degraded areas (i.e. pasture) to native vegetation that contains both regrowth and remnant areas. All areas were impacted by weeds due to previous disturbance from logging and subsequent cattle grazing. More than 35 weed species impact the site at varying levels with the most notable species across the site being Lantana (Lantana camara). Edges are impacted by exotic vines such as Glycine (Neonotonia wightii), the understorey by many herbaceous weeds such as Mistflower (Ageratina riparia) and rainforest zones by persistent weeds such as Coral Berry (Rivina humilis) and Passion Vines (Passiflora spp.) to name a few. Approximately 60 hectares of open area are dominated by pasture grasses and other weeds.

The aim of the project is to restore, to the extent possible, the structure, function, dynamics and integrity of the pre-existing vegetation and the sustaining habitat that is provided. Our goals are to:

  • Improve the health of vegetation and habitat types across the site
  • Improve connectivity for flora and fauna
  • Reduce fuel levels in fire prone ecosystems and the risk of hot fires sweeping through the site and wider landscape
  • Increase the resilience of the site
  • Improve water quality
  • Increase the health, populations and distribution of threatened species – flora and fauna
  • Reduce the need for weed control maintenance over time i.e. to a level of minimal maintenance
  • Provide nature based recreational opportunities and environmental education along this section of the Gold Coast Hinterland Great Walk

Planning. An ecological restoration plan was developed after detailed site assessments and the site was divided into precincts, zones and sub-zones to assist directing works. Information in the plan included species lists, weed control information, maps and detail on how to restore each area and progressively link zones. A detailed fire management plan was also developed for the site that took into account wildfire mitigation, restoration zones, the location of threatened species, site objectives, REs including their recommended fire regimes, and the capacity of areas to regenerate.

Works to date. Works over the last 9 years have covered more than 190 ha. The main approach to restoration has been via assisted regeneration consisting mainly of large scale weed control and the fencing of areas to reduce the impact of cattle. Further works have involved planting a section of creek to assist stability and connectivity across a section of the site; and the propagation and translocation of four threatened flora species (details not disclosed for security reasons).

Where low intensity fuel reduction burns were conducted in dry sclerophyll vegetation, timely follow up weed control was applied to ensure re-shooting Lantana, Molasses Grass (Melinis minutiflora) and other weeds did not fill gaps and to support the colonisation and growth of native vegetation. In remnant and regrowth vegetation, systematic weed control using a range of techniques has been applied. E.g. large areas of Lantana were controlled using three techniques: cut, scrape and paint where it was in close proximity to native plants; over-spraying after isolating infestations; and, spot-spraying when it germinated or was re-shooting. Weed species were continually suppressed to ensure native species germinated and grew to a point where most gaps have been filled with native vegetation. As each area developed and maintenance reduced, efforts were put into continually expanding the work fronts.

A propagation and translocation project was also implemented in partnership with Seqwater. More than 1150 individuals (four species) have been propagated, planted into their particular niche and have been monitored and reported on annually. This will continue until all species are considered to be self-sustaining i.e. flowering, fruiting and reproducing.

(a)NCA8n_20080502

(b)NCA8n_20080827

(c) NCA8n_20090716

(d)NCA8n_20100625

(e)NCA8n_20110630

(f)NCA8n_20151130

Figure 1, (a-f) represents an annual sequence of recovery after control of Lantana and subsequent weed at one photopoint from 2008 to 2011, with the last photo taken in 2015. The results reflect accurate and timely weed control to support the recovery of native vegetation. (Photos: City of Gold Coast)

Results to date. As of July 2015, weeds have been significantly reduced across the 190 ha treated area to a point where maintenance is being applied, with some areas requiring little to no maintenance. In a number of areas this reduction of weed has also significantly reduced fuel levels.

Increased abundance and diversity of native vegetation has occurred across a range of ecosystem and habitat types within the reserve. Open areas once dominated by dense Lantana have taken approx. 3 years to naturally regenerate with a range of pioneer, early secondary and later stage rainforest species (Figs 1-3). Many of those areas now include continuing recovery of later stage species and contain a large diversity of seedlings, groundcovers and ferns. More diverse communities have recovered with a large range of species (depending on the ecosystem / ecotone) and support a diversity of fauna species. Works in four of the larger precincts have now joined up and weed control works are continuing to expand all regenerating areas.

More than 7000 plants installed along the open riparian stretch are establishing with native species regenerating amongst the planting. After approx. 7 years the average height of the planted canopy is approx. 5-7m tall.

Ongoing works: All current work zones are being continuously extended ensuring progress made is maintained. The open area (e.g. paddock) is being reduced over time as vegetation is encouraged to expand (i.e. by continuing to control weeds to past the drip lines of all native vegetation). Fences that currently contain cattle (i.e. to assist managing open areas for access, fire management and to ensure funds are spent in more resilient areas) are being moved to continue to reduce the size of highly degraded areas. Fire management, large scale weed control and the monitoring and evaluation of threatened species, together with fauna surveys, is continuing.

Stakeholders and funding bodies: Natural Areas Management Unit (NAMU), City of Gold Coast and Seqwater. Contact Information Paul Cockbain, Team Leader Restorations +61 7 5581 1510

 

Post-sand extraction restoration of Banksia woodlands, Swan Coastal Plain, Western Australia.

Deanna Rokich

Key words: research-practice partnership, adaptive management, smoke technology, cryptic soil impedance, topsoil handling.

Figure 1. Examples of undisturbed Banksia woodland reference sites.

Introduction. Banksia woodlands were once a common and widespread feature of the Swan Coastal Plain, Western Australia (Fig. 1); today less than 35% of the original Banksia woodlands remain in metropolitan Perth. When sand extraction activities were permitted over 25 years ago, Hanson Construction Materials opted to go well beyond the statutory minimum requirement of re-instating local native species. Instead, Hanson committed to meet the challenge to return post-sand extracted sites (Fig. 2) to an ecosystem closely resembling the pre-disturbance Banksia woodland. To achieve this high resemblance to the reference ecosystem, Hanson operations sought the assistance of the Science Directorate team within the Botanic Gardens and Parks Authority in 1995. BGPA developed and implemented a research and adaptive management program with Hanson, resulting in a collaboration involving graduate and post-graduate student research programs into key facets of Banksia woodland ecosystem restoration, application of outcomes into restoration operations, and finally, restoration sites that are beginning to mimic reference sites (Fig.3).

Prior to the partnership, species richness and plant abundance, and thus restoration success, was limited in the rehabilitation. Research and adaptive management subsequently focused on improvements in soil reconstruction; topsoil management; seed germination enhancement (including smoke technology); seed broadcasting technology and whole-of-site weed management.

Monitoring. BGPA scientists have been undertaking annual plant monitoring of Banksia woodland restoration activities within reference and restoration sites for ca 15 years. This has resulted in data-sets on seedling emergence and plant survival within a range of sites, culminating in the development of annual performance criteria and ultimately, the ability to measure restoration performance in the short (e.g. from seedling emergence) and long-term (e.g. from plant survival).

Fig2d

Figure 2. The greatly reduced Banksia woodland sand profile following sand extraction, with topsoil being spread onto the pit floor.

Results. Consolidation of ca 15 years of data from >50 sites (encompassing a range of topsoil quality and climatic conditions) has revealed that stem density and species richness fall into three levels of restoration:

  • good restoration quality (high topsoil quality and favourable climatic conditions).
  • medium restoration quality (poor topsoil quality or unfavourable climatic conditions).
  • poor restoration quality (poor topsoil quality and unfavourable climatic conditions).

The integration of key research areas has resulted in:

  • Identification of first year species re-instatement being the blueprint for long-term species re-instatement.
  • Observation of cryptic soil impedance and extremely high plant loss in the standard ‘topsoil over overburden’ profile during the 2nd summer following restoration, but higher plant re-instatement and better ecosystem dynamics in the long term.
  • Improvement in seedling re-instatement, illustrated by perennial species return increasing from less than 10% to more than 70% (i.e. >100 perennial species), and stem density return of >140 perennial plants per 5m2 in Year 1, primarily due to improved topsoil handling methods – i.e. good quality, fresh and dry topsoil.
  • A ten-fold increase in the stem density of seedlings derived from direct-seeding due to innovative seed coating technology, delivery to site technology and sowing time optimisation.
  • Trebling of seedling recruitment success due to application of smoke technology.
  • Minimised weed invasion through the use of good quality and fresh topsoil, burial of the weed seedbank and prompt active weed management.
FIg3a

Figure 3. Restoration sites after 8 years, illustrating the return of the Banksia trees.

Implications for other sites. The post-sand extraction sites have provided important lessons and information about the management and restoration needs of Banksia woodlands – e.g. a high level of intervention is necessary, whilst cross-application of general restoration principles are not always possible for Banksia woodlands – useful for all those involved with managing and restoring Banksia woodland fragments within the broader Perth region.

Current and future directions. Hanson is committed to ongoing improvement through research – continually testing and employing new research techniques, programs and equipment that are recommended from BGPA research programs.

Post-sand extraction restoration practices now involve:

  • re-instating the soil profile in its natural order of topsoil over overburden, in spite of the cryptic soil impedance witnessed in the overburden in the 2nd summer following restoration;
  • striving for highest seedling establishment in the first year of restoration, prior to onset of soil impedance;
  • stripping and spreading only good quality (free of weeds), fresh and dry topsoil;
  • conserving topsoil by a strip:spread ratio of 1:2 (i.e. stripping over 1ha and spreading over 2ha);
  • burying direct-sown seeds given that seed displacement from wind and invertebrate activity is prolific during the typical seed sowing season; and
  • ceasing the common practices of mulching sites and tree-guarding plants as they provide negative or no benefits.

The partners are considering re-doing sites rehabilitated during 1991-1994, prior to research, in order to improve species diversity.

Acknowlegments: Botanic Gardens and Parks Authority and Hanson Construction Materials are the key parties in this project; involving many individual managers, researchers and students.

Contact: Deanna Rokich – Deanna.Rokich@bgpa.wa.gov.au