Category Archives: Restoration & management theory

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 practioners 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. Major funding for the project was provided by Southcoast Natural Resource Management Inc., via the Federal Government’s National Landcare Program and the Biodiversity Fund. Of note is also Bush Heritage Australia’s significant investment in the initial purchase of the property, without which the project would not have been possible.

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.

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

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.

Brush pack experiment in restoration: How small changes can avoid leakage of resources and underpin larger scale improvements for restoration and rehabilitation

David Tongway and John Ludwig

Key words: Landscape Function Analysis, biological foci, water harvesting, desertification, erosion

The following experiment illustrates how relatively small changes to redirect water flow can capture water and other biological resources at a restoration site. However the process occurs not only at the micro scale but cumulates to site and landscape scales, making it a primary underpinning principles of a method of site analysis, Landscape Function Analysis (LFA) that has been applied across Australia and other countries to assist land managers counter desertification by redesigning processes that regulate the flow of resources, minimise losses and foster cycling. See http://members.iinet.net.au/~lfa_procedures/

The LFA mindset and methodology involve a purposeful change of focus from listing the biota/ species present or absent at a site, to an examination of the degree to which biophysical processes deal with vital resources with respect to stresses arising from management and climatic events.

Fig 1 before

Fig. 1. Before: bare, crusted, low OC soil, erosion, and high water runoff mainitained by low but persistent, set-stock grazing by sheep and kangaroos.

Fig 2. after treatment

Fig. 2. The restoration treatment was simply to build brush-packs across the contour to trap water, soil and plant litter, slowing overland outflow. This also prevented the grazing down to ~1cm. Grass plants were able to maintain about 10cm of photosynthetic tissue.

Fig 4

Fig 3. After 7 years. Clearly the soil properties have improved the ‘habitat quality’ for the target vegetation.

Fig 5 14 years after

Figure 4. After 14 years, native vegetation re-established.

Fig 3. detail of bushpack after 3 years.

Fig 5. Detail of the brushpack after 3 years showing micro-structures capable of slowing water and accumulating resources.

1. tongway table

ANOTHER KEY OBSERVATION RELEVANT TO RESTORATION AND REHABILITATION

Where resources are not captured or leak out of a system, patchiness will become evident as resources self-organise around foci of accumulation – creating ‘patches’ where resources accumulate and ‘interpatches’ from which they ‘leak’.

The Golden Rule for rehabilitation is: “Restore/replace missing or ineffective processes in the landscape in order to improve the soil habitat quality for desired biota.”

Fig 6. Grassy sward healthy

Fig. 6. A grassy sward patch where the grass plants are close enough together that the water run-off is unable to generate enough energy to redistribute the grassy litter, which is evenly distributed. (The slope is from top to bottom in the image.)

There is also no evidence of sediment transport (not visible in this image). This is because of the tortuous path and short inter-grass distance. It would be possible to derive the critical grass plant spacing for “sward” function in any landscape, taking into account slope, aspect and soil texture.

Fig 7. Grassland in patch-interpatch mode, due to exceeding the critical runoff length for erosion initiation. (Slope is from top to bottom.)

Note that litter and sediment have both been washed off the inter-patch and have been arrested by a down-slope grass patch. Note the orientation of the grassy litter strands.

 

 

 

 

 

 

 

 

 

 

 

 

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

Fire as a tool in maintaining diversity and influencing vegetation structure – Grassy Groundcover Restoration Project

Paul Gibson-Roy

Greening Australia’s Grassy Groundcover Restoration Project commenced in 2004 to investigate the feasibility of restoration of grasslands and grassy woodlands (primarily by direct seeding) in the agricultural footprint of Australia. To date the project has achieved the reconstruction of grassy understories in grassland or grassy woodland on near to 100 sites in ex-agricultural land (predominantly across Victoria, but increasingly in southern to central New South Wales and mid-lands Tasmania). Post establishment we use fire in our sites to reduce biomass, particularly to inhibit grass growth which over time become the dominant life form, just like trees can in other communities. Opening the grass canopy allows for the small forbs and sub-dominant grasses to regenerate. Burning in particular can help create these canopy gaps and in a cost-effective way.

Fig 1. Snake Gully CFA burn at Chepstowe.

Fig 1. Snake Gully CFA burn at Chepstowe.

Fig 2. Restored herb-rich grassland on roadside near Wickliffe.

Fig 2. Restored herb-rich grassland on roadside near Wickliffe.

Fig 3. Differential management of Kangaroo Grass at Rokewood Cemetery.

Fig 3. Differential management of Kangaroo Grass at Rokewood Cemetery.

Operational challenges can and often do arise considering sites are located within urban or agricultural footprints where protection of life and property is paramount. This at times prompts us to consider alternative methods of biomass removal such as through grazing (sometimes used as a method for annual weed control) and mowing when burning is deemed inappropriate. These alternative or complimentary biomass reduction methods can also have additional benefits. For example, mowing and producing bales of cut straw, if cut in early spring or autumn, can be used for fodder. This is also the case with grazing. Alternatively, if sites are cut and baled in late spring or summer when grasses contain ripe seed, the hay can be moved and spread at other locations to create a grassland elsewhere.

While the project has carried out various combinations of these approaches at our restored grasslands in recent years, the following list includes a few examples of their use.

  1. Burning at Chepstowe (located to the west of Ballarat, Victoria) to reduce grass biomass and allow forbs to establish and persist. The burn is being conducted by Snake Gully CFA members (Figure 1).
  2. The nationally threatened species – Hoary Sunray (Leucochrysum albicans tricolor) and Button Wrinklewort (Rutidosis leptorrynchoides) were introduced by direct seeding along with many other ground layer species onto a roadside near Wickliffe, Victoria. Following establishment the grassland has been managed with fire by the Wickliffe CFA so that grasses do not dominate and the rare species can recruit and spread. (Figure 2.)
  3. Kangaroo Grass (Themeda triandra) growth has been the focus of differing management techniques within the Rokewood cemetery reserve Victoria (under the Cemetery Trusts grassland management plan). This remnant grassland contains the largest Victorian population of the nationally threatened Button Wrinklewort. To avoid the Kangaroo grass dominating the herb rich areas, it is maintained by fire, whereas in the approaches to the burial area it is kept mown low for function and protection of the memorial infrastructure. (Figure 3).
  4. Similar opening of a restored grassy canopy is achieved at Chatsworth in south western Victoria where a grassland currently dominated by Wallaby Grass (Rytidosperma setaceum) was mown and baled (Figures 4 and 5). This material was used to as fodder by the landholder.
  5. A late autumn burning of herb-rich restored grassland at Hamilton, Victoria, undertaken by the Buckley Swamp CFA (Figure 6).
  6. The aforementioned site at Hamilton taken in the following spring. It shows visitors touring the restoration where Common Everlasting (Chrysocephalum apiculatum) and many other sub-dominant forb species are in full bloom (Figure 7).
  7. Diverse restored grassland located adjacent to a wheat crop at Point Henry, near Geelong, Victoria. This site 16 ha site has been maintained over time by combinations of burning and cutting and baling (Figure 8).
Fig 4. Wallaby grass dominated grassland at Chatsworth pre-baling.

Fig 4. Wallaby grass dominated grassland at Chatsworth pre-baling.

Fig 5. Wallaby grass dominated grassland at Chatsworth post-baling.

Fig 5. Wallaby grass dominated grassland at Chatsworth post-baling.

Fig 6. Buckley Swamp CFA conducting a late autumn burn of restored herb-rich grassland near Hamilton.

Fig 6. Buckley Swamp CFA conducting a late autumn burn of restored herb-rich grassland near Hamilton.

Deciding which method or combination of biomass removal techniques to use, and at what time can be complex and there is no textbook. Good management is about constantly assessing the landscape and prevailing conditions to identify prompts for action. It is also about having the right networks and technical capacity available when required. As a general rule we find that when a site has greater than 70% vegetation cover of the ground surface and dry material is being held above 150 mm, there is enough combustible material to carry a flame. This condition also indicates that that the gaps in the vegetation are starting to close up.

Contact: (Dr) Paul Gibson-Roy. Lead Scientist, Greening Australia.Tel: +61 437591097. Email: PGibson-Roy@greeningaustralia.org.au

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

 Fig 7. Spring and wild flowers are in bloom at Hamilton.


Fig 7. Spring and wild flowers are in bloom at Hamilton.

Fig 8. Species and functionally diverse restored grassland adjoining a wheat crop near Geelong.

Fig 8. Species and functionally diverse restored grassland adjoining a wheat crop near Geelong.

Managing fire for nature conservation in subtropical woodlands

Emma Burgess, Murray Haseler and Martine Maron

Introduction. A study investigating the response of bird assemblages to mosaic burning is being conducted on 60,000 hectares private nature reserve in the Brigalow Belt bioregion of Queensland (Fig 1). The Brigalow Belt has recently experienced high rates of native vegetation clearing, motivating Bush Heritage Australia (BHA) to purchase and protect the property in 2001. The subsequent removal of cattle and horses from Carnarvon Station Reserve has increased grass and herb biomass. The seasonal surge in productivity the property now experiences however, increases the potential for more intense, frequent and extensive fires in hot, dry conditions. The risk of such wildfires needs to be managed, and a common approach to such management is prescribed burning. But how to ensure nature conservation objectives are still met?

Fig 1. Locality map of Carnarvon Station Reserve

Fig 1. Locality map of Carnarvon Station Reserve

In fire ecology, there is a common assumption that if we introduce a range of burn conditions to produce a mosaic of patches with different fire histories (pyrodiversity) – then the resulting diversity in fire histories and the greater representation of successional stages of vegetation is expected to accommodate more species in a given area (Fig. 2). Reducing the spatial scale at which fire history turns over- the “breaking up” of country- is also known as the patch mosaic burning approach.

Fig 2. Diagram of mosaic burning approach

Fig 2. Diagram of mosaic burning approach

Whilst we assume that pyrodiversity will give us increased habitat diversity, and therefore greater animal diversity, there is uncertainty as to the scale (alpha, beta or gamma diversity) at which pyrodiversity might influence biodiversity (Fig. 3). Alpha diversity is the total number of different species within a site or habitat; beta diversity is the difference in species composition between sites or habitats; and gamma diversity is the number of different species across all sites or habitats in the area of interest. At what spatial scale do we see the benefit for birds of mosaic burning (Fig. 3)?

Fig 4. Fire-sensitive semi-evergreen vine-thicket extending into Mountain Coolibah (Eucalyptus orgadophila) woodland, Carnarvon Station Reserve

Fig 4. Fire-sensitive semi-evergreen vine-thicket extending into Mountain Coolibah (Eucalyptus orgadophila) woodland, Carnarvon Station Reserve

Methods: We examine the relative influence of the diversity of fire histories, spatial configuration of these fire histories, spatial extent of particular fire histories and other measures of environmental heterogeneity on:

  1. Aggregated measures of bird species richness at both the landscape- (100 ha) and local-scale (1 ha); and
  2. Response of different bird foraging guilds to mosaic burning, at both the landscape- and local-scale.

 So what did we find? The diversity of fire regimes in the 100-ha landscape did not correlate with average site (alpha) or landscape- (gamma) diversity of birds. Rather, the total area of longer-unburnt vegetation was important for increasing bird richness at the landscape-scale, and sites in longer-unburnt vegetation had more species.

Although areas burnt in prescribed burns supported lower bird diversity compared to long-unburnt areas, prescribed burns are still necessary to reduce the risk of extensive wildfire. Such burns should focus on breaking up areas of high fuel at the beginning of the dry season (Fig. 4). The extent of long-unburnt vegetation that can be maintained with careful fire management is yet to be determined, but its importance as bird habitat is clear.

Acknowledgements: This work could not have been completed without funding and logistical support provided by AndyInc Foundation, Bush Heritage Australia and UQRS. Thanks to Peta Mather and Donna Oliver who assisted with field work. This study was carried out with approval from the Animal Ethics Committee at the University of Queensland (approval no. SGPEM/325/11/UQ).

Fig 4. Fire-sensitive semi-evergreen vine-thicket extending into Mountain Coolibah (Eucalyptus orgadophila) woodland, Carnarvon Station Reserve

Fig 4. Fire-sensitive semi-evergreen vine-thicket extending into Mountain Coolibah (Eucalyptus orgadophila) woodland, Carnarvon Station Reserve

Contact: Dr Emma Burgess University of Queensland, Email: e.burgess4@uq.edu.au

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

Forested wetland regeneration project, The Gap Road Woodburn, NSW

Julie-Anne Coward

Contract bush regeneration works involving fire and weed management commenced in 2011 in 2.5 ha of endangered ecological coastal floodplain communities at the Cowards’ property on the Gap Road, Woodburn in northern NSW (Fig 1). An area of 7.19 ha of the 10ha property had been recently covenanted for conservation by new owners and 2 small grants were gained to convert the previous grazing property back to forested wetland. Remnant vegetation existed on the property and regrowth was already occurring, although extensive areas were dominated by exotic pasture grasses, particularly >1m high swathes of Setaria (Setaria sphacelata).

Works commenced with spraying of the weed with herbicide and regular follow up spot spraying of weed regrowth. However, because the dead Setaria thatch was taking a long time to break down (and high weed regeneration was likely) a burn was carried out to hasten the recovery responses to fit within the 3 year funding cycle. The works were monitored before and at 6 monthly intervals using 6 (9m2) quadrats in each of hot burn, cool burn and unburnt areas (Fig 1).

Fig 1. Works zones at the Gap Road wetland

Figure 1. Works zones at the Gap Road wetland – mapped in April 2013 where the quadrats were laid out. and data recorded prior to and at 6-monthly intervals after treatment.

Works undertaken. A 2-3m wide firebreak was cut around the burn area and a burn was conducted in dry conditions on Oct 19th 2012 (Fig 2) by the landholders, assisted by Minyumai Green Team and with the local fire brigade on standby. The fire burnt approximately 0.5 ha of the Setaria-dominated area, most of which had been previously sprayed (Fig 2).

Results. A more complete (and presumably hotter) burn was achieved in the sprayed areas (Figs 3 and 4). Setaria and Ragweed germinated prolifically, with a few natives and the site was virtually blanket sprayed with glylphosate. By the second follow up natives had started to regenerate so spot-spraying was used thereafter, taking care to protect the natives. Within 5 months quadrats in the sites that burned hotter achieved over 50% native cover, while the unburnt area achieved only half (25%) that cover. Both areas ultimately achieved similar recovery of natives, but markedly higher spot spraying inputs over longer time frames were needed in the unburnt areas compared to the hotter burn areas.

Over the three year contract, unexpectedly high and prolific regeneration occurred of 35 species of native forbs, sedges and grasses (germinating from buried seed banks) and 7 species trees and shrubs (largely from seed rain) (Fig 5). However, weed germination was also prolific, particularly in unburnt areas, and required at least monthly levels of continual suppression.

fig 2. The burn itself (Oct 17, 2015)

Figure 2. The burn itself (Oct 17, 2015)

Figure 3. Sprayed Setaria prior to the burn.

Figure 3. Sprayed Setaria prior to the burn.

Figure 3. Prolific native groundcover and tree regeneration 2 years after the burn and as a result of consistent spot spraying.

Figure 3. Prolific native groundcover and tree regeneration 2 years after the burn and as a result of consistent spot spraying.

Lessons learned. The proximity of remnant vegetation (within 100m) and intact soil profile was important to the native recovery. At least monthly weed control is essential and can achieve results on its own. However, the project involved substantial volunteer time as well as contract labour – and when labour was insufficient new weed populations formed in the disturbed areas that then required more intensive treatment to overcome. Comparing the demand for weed control in burnt and unburnt areas showed that the feasibility of weed control is very much reduced without the use of fire to flush out weed at the outset.

Acknowledgements: The project is dedicated to the memory of Murray Coward who helped initiate the project. Minyumai Green Team (Daniel Gomes, Justin Gomes, Chris Graves and Andrew Johnston) have kept the project on track over the years, with assistance from Tein McDonald. Thanks is due to the EnviTE team, particularly Virginia Seymour, for their work at the site in the first 18 months. The project is covenanted with the Nature Conservation Trust of NSW (NCT) and received some initial funding from NCT. It subsequently gained a $15K Private Land Conservation Grant (funded by Foundation for National Parks and Wildlife and managed through the NCT) and has now gained a second, similar grant to continue and expand the works.

Contact: Julie-Anne Coward, Gap Road Woodburn. Email: mjcets1@bigpond.com

Re-introducing burning to Themeda Headland Grassland EEC, Narooma, NSW.

Tom Dexter, Jackie Miles, Deb Lenson

Key Words: Fire management, threatened ecosystem, Kangaroo Grass, weed management, Themeda

Introduction: In 2012, Eurobodalla Shire Council commenced a project to preserve local stands of declining Themeda Headland Grassland on Council managed land on three small headlands north of Narooma, NSW. Themeda Grassland on Seacliffs and Coastal Headlands is an Endangered Ecological Community (EEC) that grows on higher fertility soils and is listed under the NSW Threatened Species Conservation Act 1995.

Burning was trialed at two of the three sites to test whether fire could improve the environmental integrity of these sites. This trial has potential implications for the much larger stands of this EEC in various conservation reserves scattered along the NSW coastline as there are many which are not currently actively managed.

The three sites were slashed annually until 2010. While the dominant grass, Kangaroo Grass (Themeda triandra) was still present on all sites, the sites exhibited some decline in Kangaroo Grass cover and vigour, with weed present on all three sites (Fig 1). Slashing had kept the headlands free from shrubs however windrows of slashed grass suppressed Kangaroo Grass and appeared to encourage weed invasion. One of the sites, which was left unburnt for logistic reasons, was initially in worse condition than the other two due to the presence of an old vehicle track and more extensive weed cover particularly from Kikuyu (Pennisetum clandestinum).

The intensity of a burn is likely to vary on a seasonal basis and is dependent on the build-up of dead thatch and the prevailing conditions on the day. There is basis to believe that the traditional aboriginal burning would have taken place in Autumn and would have been a relatively cool burn. The optimum time to burn when considering the constraints of weed invasion is early spring.

Fig 1. Mowing damage at Duesburys Beach headland

Fig 1. Lines of bare ground indicate the location of windrows of dead grass from a history of mowing at Duesburys Beach headland

Works undertaken: Two successive burns were conducted in early spring on 2 of the 3 headlands, in August 2013 and August 2014 (Fig 2). The burn in 2013 was hotter than the burn in 2014 due to a higher build up of Kangaroo Grass thatch prior to the burn.

Follow-up weed control was implemented after the burns as the fire created gaps between the grasses and allowed targeted chemical control minimizing off target damage to Kangaroo Grass and other native species.

Data were collected on three occasions using ten 1 x 1 m quadrats, established along a 50 m transect spaced at 5 m intervals (one of these for each headland). The initial baseline data were recorded in Nov 2012, prior to the spring burns, and in each successive summer (2013/14 and 2014/15) following the burns.

Fig 2. Dalmeny Headlands burn 2015

Fig 2. Typical burn on the headlands

Results to date: The burnt areas (Figs 3 and 4) showed a significant decrease of annual exotic grasses; especially of Quaking Grass (Briza maxima) and Rats Tail Fescue (Vulpia spp.). The burnt areas also showed vigorous Kangaroo Grass growth and moderate seed production of that species. Two native species -Dwarf Milkwort (Polygala japonica) and Matgrass (Hemarthria uncinata Fig 5) not recorded prior to treatment were found after treatment in the quadrats. The most abundant native forbs, Swamp Weed (Selliera radicans) and Indian Pennywort (Centella asiatica) have persisted on the quadrats but not increased (Fig 6). Some exotic forbs – e.g. Yellow Catsear (Hypochaeris radicata) and Scarlet Pimpernel (Anagallis arvensis) have taken advantage of the removal of grass biomass and have also increased, further future analysis will determine whether this increase will impact on the native forbs. Perhaps the most important finding is the Coast Banksia (Banksia integrifolia) seedlings were killed by the fire allowing the sites to remain grassland.

The unburnt headland continues to deteriorate, with ongoing evidence of continued senescense of Kangaroo Grass, no Kangaroo Grass seed production, and exotic plants continuing to replace Kangaroo Grass in parts of the site. Kikuyu is the main exotic species on this site and is responsible for continued suppression of the native components of the grassland. There is also evidence of shrub invasion beginning to occur. It is anticipated that this site will be burnt in spring 2015.

Fig 2. Duesburys Point just after fire, Sept 2013

Fig 3. Duesburys Point just after burning, Sept 2013

Fig 3. Same site 11 months later, Aug 2014

Fig 4. Same site 11 months later, Aug 2014

What we learned: Kangaroo Grass remains vigorous throughout the burnt sites. The results to date show annual burning to be generally beneficial to the herbaceous components and associated grasses of this EEC. There was a higher success of exotic annual grass control in the first year which is most likely attributed to a hotter fire and perhaps timing. The first year also had accumulated multiple years of thatch which may have assisted fire intensity. Supplementary chemical control was effective, particularly when the fire created gaps between the grasses, allowing for better targeted chemical control.

Future directions: So far the results have shown that an August fire followed by the targeted chemical control of exotic grasses has considerable positive influence on the overall environmental integrity of this ecosystem. The annual burning allows the EEC to remain a grassland by killing off Coast Banksia and Coastal Acacia seedlings. It invigorates Kangaroo Grass growth and reduces the biomass of exotic perennial grasses at least in the short term. This again creates an opportunity in the aforementioned targeted chemical control. The herbaceous composition of the headland also remains intact and future analysis will determine whether burning has either a neutral or positive effect on growth. Kikuyu, Paspalum (Paspalum dilitatum) and annual exotic weeds continue to be the main problem. Increased post-burn selective herbicide application or hand weeding and planting of Kangaroo Grass tubestock may help to restore the grassland more rapidly than use of fire with limited weed control alone. Ongoing funding is being sought to continue the works over coming years and achieve further positive future outcomes.

Acknowledgements: The works were undertaken by Eurobodalla Shire Council with funding from the NSW Environmental Trust. Fire assistance from the NSW Rural Fire Service and cultural advice provided by Elders of the Walbunja people.

Contact: Tom Dexter; Environment and Sustainability Project Officer; Eurobodalla Shire Council (PO Box 99 Vulcan St Moruya 2537, Australia. Email: tom.dexter@eurocoast.nsw.gov.au).

Fig 5. Hemarthria uncinata was more evident after fire. (Duesburys Beach headland.)

Fig 5. Hemarthria uncinata was only evident after fire. (Duesburys Beach headland.)

Fig 5. More forbs among the grass after fire at Duesburys Point – e.g. Sellaria radicans

Fig 6. The forb Sellaria radicans persisted  among the grass after fire.

 

Wompoo Gorge Lowland Subtropical Rainforest Restoration Project, Coopers Creek, New South Wales

Key words : Connectivity, Lowland Subtropical Rainforest, Threatened Species

Introduction. Much of the state- and nationally listed Lowland Subtropical Rainforest at Wompoo Gorge, located on Coopers Creek near Rosebank, was partially cleared for pasture early last century. Parts of the cleared forest regenerated naturally with the removal of agricultural activities from the site during the 1940s-50s, but Lantana (Lantana camara) established in large gaps (Fig 1) and prevented any further rainforest regeneration. This weed domination reduced the function of an important habitat linkage between Nightcap and Goonengerry National Parks. Twenty-seven threatened species (10 threatened flora species and 17 vulnerable animal species) have been recorded on the site, which has been identified as a key climate change and wildlife corridor.

In 2009 a program of ecological restoration commenced, guided by the recommendations of the Wompoo Gorge (South) Ecological Restoration Plan (updated in 2013). The aim of the restoration works was to control Lantana and other weeds, restoring the integrity of the rainforest and helping to supporting the region’s exceptional biodiversity.

A monitoring program was established on site prior to commencement of works. This included eight transects and photopoints. Structural and floristic information has been collated and photos taken prior to the commencement of works, and subsequently over the course of restoration work. Data have been entered into then MERV (Monitoring and Evaluation of the Restoration of Vegetation) database and used to produce reports.

Figure 1. (map) Lantana cover prior to restoration. By 2014 very little lantana remained with regenerating rainforest taking the place of weeds.

Figure 1. (map) Lantana cover prior to restoration. By 2014 very little lantana remained with regenerating rainforest taking the place of weeds.

Works undertaken: Lantana has been controlled by a range of methods (Figs 2-4) including: mechanically with a tractor; spraying with a splatter gun; over-spraying dense, less accessible areas; hand weeding with brush hooks and loppers; and, cut/scrape and paint of scattered Lantana among remnant vegetation. Other less dominant weeds have been controlled to facilitate replacement of Lantana with regenerating rainforest. Follow-up work includes flattening down dead Lantana, spot spraying and hand weeding. No planting has been undertaken but fruit from native plants on site has been collected and spread throughout regeneration areas.

Figure 2. September 2009: Prior to lantana control

Figure 2. September 2009: Prior to lantana control

Figure 3.  17 September 2009: Tractor crushes down lantana

Figure 3. 17 September 2009: Tractor crushes down lantana

Figure 4. 21 October 2009: Second tractor run slashing lantana

Figure 4. 21 October 2009: Second tractor run slashing lantana

Results: Lantana has been virtually eliminated from extensive areas and vigorous regeneration of a high diversity of species has occurred (Figs 5-6). Common regenerating species include: Poison Peach (Trema aspera), Red Cedar (Toona ciliata), Giant Stinging Tree (Dendrocnide excelsa), Tamarind (Diploglottis australis), Sandpaper Figs (Ficus coronata) White Cedar (Melia azedarach) Bangalow Palm (Archontophoenix cunninghamiana), Brown Kurrajong (Commersonia bartramia), Pencil Cedar (Polyscias murrayi), Celerywood (P. elegans), Quandong (Elaeocarpus grandis) , Black Bean (Castanosperma australis), Sally Wattle (Acacia melanoxylon). Groundcovers included Soft Bracken Fern (Calochlaena dubia), Cunjevoi (Alocasia brisbanensis) Juncus (Juncus sp.), Cyperus (Cyperus spp.) and Basket Grass (Oplismenus aemulus). A range of later stage rainforest species have also germinated including Hairy Walnut (Endiandra pubens), Maiden’s Blush (Sloanea australis) and White Bolly Gum (Neolitsea dealbata).

Figure 5. ‘’Oct 2010: Resilient native regeneration in tractor cleared area

Figure 5. Oct 2010: Resilient native regeneration in tractor cleared area

Figure 6. May 2014: Natives have replaced lantana throughout cleared area

Figure 6. May 2014: Natives have replaced Lantana throughout cleared area

What we have learned. Wompoo Gorge has proven to be a highly resilient site, located as it is between two major sources of propagules. The site’s unique location, resilience and beauty has made it an ideal site to educate and inspire the community to restore rainforest Field days held on site have assisted in raising regional awareness of the value of the Lowland Rainforest EEC, the habitat it provides and of the degrading impacts of weeds. Various weed control techniques have also been discussed and demonstrated. Involving Green Army participants alongside professional regenerators has helped Green Army participants gaining valuable knowledge, skills and training in ecological restoration.

In 2014 NSW National Parks and Wildlife Service acquired the property realising the goal of former property owner Dailan Pugh to protect the property in perpetuity for the benefit of conserving native species and for future generations.

Acknowledgements: The project has received funding from the NSW Environmental Trust’s Restoration and Rehabilitation program. Additional funding has been invested through the former Northern Rivers Catchment Management Authority, the Great Eastern Ranges Initiative and a Raymond Borland Landcare grant. In 2015 Green Army teams have commenced working on site, alongside professional bush regenerators, undertaking additional and complimentary restoration works.

Contact: Paul O’Connor, Technical Manager, EnviTE Environment, 56 Carrington Street (P.O.Box 1124) Lismore  2480 Australia.

Tel: +61 2 6627 2841 Mob: + 61 427 014 692. Email: paulo@envite.org.au

 

Twelve years of healing: Rehabilitating a willow-infested silt flat – Stormwater Management.

Alan Lane

Key words: urban stream, erosion, siltation, soft engineering, head wall

Introduction: Popes Glen Creek is a small permanent stream rising close to the centre of the township of Blackheath, NSW, Australia. Its upper catchment (10 ha) comprises low-permeability urban development, roadways, shops and parklands.

The funneling of runoff from the low-permeability catchment into the headwaters of Popes Glen Creek resulted in intense and destructive runoff after rain, carrying down large and small debris, depositing sheets of silt, uprooting or burying vegetation, causing erosion of the creek banks and threatening to undermine the head wall of the silt flat downstream. This resulted in the formation of a 1 ha silt flat at the headwaters of the creek, covered with dense infestations of mature Crack Willow (Salix fragilis), Purple Ossier (S. purpurea) and mid-storey and ground-layer weeds. This has been revegetated as a permanent wetland as described in a previous summary (https://site.emrprojectsummaries.org/2015/02/22/)

This summary describes the runoff management aspects of the project, where the aims were:

  1. to reduce the impact of runoff
  2. to reduce the incursion of silt
  3. to remediate the main channel
  4. to stabilise the head wall.
Fig 1: Notched weir diverting water towards sedimentation pond.

Figure 1: Notched weir diverting water towards sedimentation pond.

Figure 2: Sedimentation pond

Figure 2: Sedimentation pond

Works carried out:

1. Diversion of part of the flow and capturing sediment. A diversion channel was constructed with flow regulated by a notched weir in the main stream. This diverts approximately half the volume of the flow into a sedimentation pond were silt is captured, reducing the quantity deposited downstream (Figures 1 and 2).

2. Construction of low-impact detention cells. “Soft engineering” detention cells constructed across the silt flat from coir logs and woody debris found on site retain and slow the release of flow, dispersing it across the silt flat and raising the water table, suppressing weeds and supporting the vegetation of the created wetland (Figures 3 and 4).

3. Elimination of the highly incised main channel. Natural debris falling into the main channel creates a series of small pondages. These retain and slow the flow and allow overflow to disperse across the silt flat. (Figure 5).

4. Protection of the creek banks. Dense plantings of deep-rooted swamp vegetation e.g. Red-fruited Saw Sedge (Gahnia sieberiana) and Black Wattle (Callicoma serratifolia) (Figure 6), and loosely woven structures constructed from woody debris (Figure 7) protect creek banks and silt flat from erosion and scouring.

5. Stabilisation of the headwall. Contractors employed with funds from the Environmental Trust have constructed a major structure with railway sleepers and rock armouring to stabilise the head wall (Figures 8 and 9).

Figure 3: Volunteers building a detention cell from woody debris found on site.

Figure 3: Volunteers building a detention cell from woody debris found on site.

Figure 4: Raised water table enabled wetland sedges (Carex gaudichaudiana and Eleocharis sphacolata) to displace Creeping Buttercup (Ranunculus repens).

Figure 4: Raised water table enabled wetland sedges (Carex gaudichaudiana and Eleocharis sphacolata) to displace Creeping Buttercup (Ranunculus repens).

 

Lessons learned and future directions:  This project is on track to replace the forest of willows with wetland vegetation, transform a highly incised creek and weed-infested silt flat into a healthy Upper Blue Mountains Swamp – an endangered ecological community scheduled under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999.

The volunteer group will continue working with Council and contractors to complete the planting program and to monitor the evolution of the site, including its vegetation, water quality and colonisation by macroinvertebrates, birds and frogs.

Stakeholders and funding bodies: This work is supported by a grant from the Government of New South Wales through its Environmental Trust and by the Blue Mountains City Council,  which also oversaw the engineering works. All photographs: Alan Lane and Paul Vale.

Figure 5: A natural pondage formed when debris was allowed to remain in the stream.

Figure 5: A natural pondage formed when debris was allowed to remain in the stream.

Figure 6: Dense plantings of Black Wattle (Calicoma serratifolia) and Gahnia (Gahnia sieberiana) protect creek banks from erosion.

Figure 6: Dense plantings of Black Wattle (Callicoma serratifolia) and Gahnia (Gahnia sieberiana) protect creek banks from erosion.

Figure 7: Volunteers using woody debris to protect the silt flat from scouring.

Figure 7: Volunteers using woody debris to protect the silt flat from scouring.

Figure 8: Part of the original head wall approximately 3 m high and 20 m wide.

Figure 8: Part of the original head wall approximately 3 m high and 20 m wide.

Figure 9:  Part of structure constructed to stabilise the head wall.

Figure 9: Part of structure constructed to stabilise the head wall.

Contact information: Dr Alan Lane, Coordinator Popes Glen Bushcare Group, PO Box 388, Blackheath NSW 2785, Australia. Tel: +61 2 4787 7097; Paul Vale, Deputy Coordinator Popes Glen Bushcare Group, 81 Prince Edward St, Blackheath NSW 2785, Australia. Tel: +61 2 4787 8080; and Ray Richardson, Chairman of Steering Committee, Environmental Trust Grant 2011/CBR/0098. Tel: +61 2 4759 2534.