Category Archives: Grassland/grassy understorey

Integrating conservation management and sheep grazing at Barrabool, NSW

Martin Driver

Key words: semi-arid, grazing management, conservation management, rehabilitation, ecological restoration

Introduction. Barrabool is a 5000 ha dryland all-Merino sheep property between Conargo and Carrathool in the Western Riverina, NSW. Native pastures are the mainstay of Barrabool, as they are of other grazing properties in the arid and semi-arid rangelands of New South Wales that generally lie to the west of the 500 mm average rainfall limit.

Indigenous ecosystems at Barrabool occur as native grassland, mixed acacia and callitris woodlands and shrublands. The main grass species in the grasslands are Curly Windmill (Enteropogon sp.), White Top (Rytidosperma sp.), Box Grass (Paspalidium sp.), Speargrass (Austrostipa spp.), and Windmill Grass (Chloris sp.). Broad-leaved species include Thorny Saltbush (Rhagodia sp.), Cotton Bush (Maireana sp.) and a diverse annual forb layer in Spring..

The majority of the property has belonged to the Driver family for over 100 years. Like many of the surrounding stations a gradual but noticeable increase in exotic species occurred during the mid-to-late 20th Century, and a decline in native species. This transition has occurred because of species being transferred by livestock movements and because sheep graze not only on grass, but also saltbush shrubs and sub-shrubs as well as seedlings of native trees such as Boree (Acacia pendula) and White Cypress Pine (Callitris glaucophylla). It is well known, for example, that the preferential and continuous grazing of Boree by sheep can turn a Boree woodland into a grassland .within a manager’s lifetime unless rest and regeneration are allowed.

In recent decades – because of the Driver family’s interest in conservation and our exposure to advances in grazing management, paddock subdivision and stock water relocation – we have developed in recent decades a managed grazing system based on feed availability, regeneration capability and seasonal response to rainfall. It was our hope that this system could improve the condition of native vegetation while also improving feed availability.

Figure 1. Boree (Acacia pendula) and Thorny Saltbush (Rhagodia spinescens) in grazed paddocks at the Driver’s 5000 ha sheep property, Barabool, in the western Riverina. (Photo M. Driver).

Figure 1. Boree (Acacia pendula) and Thorny Saltbush (Rhagodia spinescens) in grazed paddocks at the Driver’s 5000 ha sheep property, Barabool, in the western Riverina. (Photo M. Driver).

Works undertaken. Over the last 35 years we have progressively fenced the property so that it is subdivided by soil type and grazing sensitivity, with watering systems reticulated through poly pipe to all those paddocks. This enables us to control grazing to take advantage of where the best feed is and move stock from areas that we are trying to regenerate at any one time; and it gives us a great deal more control than we would have had previously.

Using our grazing system, we can exclude grazing from areas that are responding with regeneration on, say Boree country, for periods of time until Boree are less susceptible to grazing; at which time we bring stock back in. We take a similar approach to the saltbush and grasses, moving sheep in when grazing is suitable and moving them off a paddock to allow the necessary rest periods for regeneration. In this way we operate a type of adaptive grazing management. We also have areas of complete domestic grazing exclusion of very diverse and sensitive vegetation which are essentially now conservation areas.

Figure 2. Mixed White Cypress Pine Woodland grazing exclosure on Barrabool with regeneration of Pine, Needlewood, Sandalwood, Rosewood, Butterbush, Native Jasmine, mixed saltbushes and shrubs. (Photo M. Driver)

Figure 2. Mixed White Cypress Pine Woodland grazing exclosure on Barrabool with regeneration of Pine, Needlewood, Sandalwood, Rosewood, Butterbush, Native Jasmine, mixed saltbushes and shrubs. (Photo M. Driver)

Results. The native vegetation at Barrabool has noticeably improved in quality terms of biodiversity conservation and production outcomes over the last 35 years, although droughts have occurred, and in fact been more frequent during this time.

In terms of conservation goals Boree regeneration and Thorny Saltbush understory restoration has been both the most extensive and effective strategy. Areas of mixed White Cypress Pine woodland have proven to be the most species diverse but also offer the greatest challenges in exotic weed invasion and management. The Pines themselves are also the most reluctant to regenerate and suffer many threats in reaching maturity while many of the secondary tree species are both more opportunistic and show greater resilience to drought and other environmental pressures. The increase in perenniality of grass and shrub components of the property have been significant, with subsequent increase in autumn feed and reduced dependence on external feed supplies.

In terms of production outcomes, after the millennium drought the property experienced three seasons in a row in which there was much less rainfall than the long term average rainfall. At the beginning of that period we had the equivalent of more than the annual rainfall in one night’s fall and then went for 12 months from shearing to shearing with no rain recorded at all. Yet the livestock and the country, however, did very well compared to other properties in the district, which we consider was due to the stronger native vegetation and its ability of the native vegetation to withstand long periods without rain.

Lessons learned and future directions. While many other sheep properties in the wider area are more intent on set stockingin their grazing practices, the results at Barrabool have demonstrated to many people who have visited the property what is possible. I am sure we are also are having some effect on the management systems of other properties in the district especially in the area of conservation areas excluded from grazing.

What we plan for the future is to explore funding options to fence out or split ephemeral creeks and wetlands and encourage Inland River Red Gum and Nitre Goosefoot regeneration.Our long term goal is to maintain the full range of management zones (including restoration zones earmarked for conservation, rehabilitation zones in which we seek to improve and maintain biodiversity values in a grazing context, and fully converted zones around infrastructure where we reduce impacts on the other zones.

Contact:   Martin Driver Barrabool, Conargo, NSW 2710 Email: barrabool@bigpond.com

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.

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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).

 

 

 

Learning from the Coreen TSRS – and scaling up biodiversity recovery works at hundreds of sites in the Riverina, NSW.

Peter O’Shannassy and Ian Davidson

Key words: Travelling Stock Routes and reserves, grazing management, rehabilitation, direct seeding, Biodiversity Fund.

Introduction. The travelling Stock Routes and Reserves (TSRs) in NSW comprise a network of publically owned blocks and linear routes that were set aside between 100-150 years ago in New South Wales (NSW) to allow landholders to move their livestock from their grazing properties to markets. They occur in prime agricultural land and remain under management by the state of New South Wales’s system of Local Land Services organisations (LLSs).

Since trucking of cattle is now the norm, rather than droving, the use of TSRs has gradually changed to more occasional grazing. Considering the concurrent gradual decline in biodiversity of many private properties in the same period this means that the remnant grassy woodland patches and corridors represent the most important habitats in the Riverina region and contain dozens of Threatened species and five Endangered Ecological Communities variously listed under the NSW Threatened Species Conservation Act 1995 (TSC Act 1995) and the Commonwealth EPBC Act 1999. A general recognition of the high biodiversity value of the TSRs (and need to counter degradation on many of them) has resulted in a shift in local policy and practice towards improving the condition of biodiversity in the reserves.

Fig. 1

Fig. 1. Coreen Round Swamp TSR 2005.

Fig. 2

Fig. 2.  Coreen Round Swamp TSR at the same photopoint in 2015. (Note the increase in Bullloak recruitment from improved grazing management.

Works undertaken at Coreen Round Swamp and Oil Tree Reserve

Managed grazing has been applied to a number of Travelling Stock Reserves in the Riverina over a 10 year period – particularly two reserves: Coreen Round Swamp and Oil Tree reserve in the Coreen area. In 1998, condition of Coreen Round Swamp was ranked high conservation quality and Oil Tree TSR medium-high. In general, both TSRs contained tree species at woodland densities, but there was a low density of regenerating palatable trees (e.g. Bulloak and White Cypress Pine), with most species where present recorded as having sparse natural regeneration. The sites contained few regenerating shrubs (again rating sparse or absent) and exotic annual grasses were common in parts, with native grass swards patchy. Weed forbs were common

Restoration works commenced at Coreen Round Swamp and Oil Tree Reserve in 2004 and focused on:

  • Manipulating the timing of grazing with selected sets of livestock at specific times to disrupt the life cycle of, particularly, annual exotic grasses to reduce these undesirable species and to prepare the way for native perennial grasses.
  • Weed control – which involved multiple visits to the site throughout the year to control the various species as they emerged and prior to seed set. Spraying of herbaceous species with knockdown herbicide continued until the balance tipped and began to move towards a stronger native composition. Woody weeds such as Olive and Pepper trees were removed by hand cutting and painting with systemic herbicides.
  • Reduction of grazing impacts: Livestock were camped in the TSR’s holding yards rather than under the trees at night. This was carried out to reduce physical damage to shrubs, trees and the ground layer and reduce fertility inputs to the soils under the trees; fertility levels that are known to favour weed species invasion of such areas.

Results. Monitoring using standard proformas and photopoints showed dramatic changes in both reserves; with sites previously devoid of recruitment now developing a layer of tree and shrub saplings including Bulloak and White Cypress Pine. Where once 20-30% of the Coreen Round Swamp TSR was highly degraded, being dominated by herbaceous and grass weeds, this degradation class has now reduced to less than 10%; with the remaining 90% being of high quality. Similarly Oil Tree TSR had around 30-40% in a similarly degraded condition, which has now been reduced to 10-15% of the area; with 80% being in moderate-high condition and moving towards high as the shrub layer improves. (See Figures 1-4).

Fig 3.

Fig. 3. Oil Tree TSR in 2005 where a mix of native grass (spear grasses) and exotic annual grasses (Wild Oats, Bromus and Rye Grass) are visible.

Figure 4


Fig 4.  Same photopoint at Oil Tree TSR in 2015 showing a sward now dominated by native grass (spear grasses) and Curly Windmill Grass (Chloris truncata).

Expansion of the program to hundreds of TSRs in the Riverina

Building on the success of the work at the Coreen Reserves, a five year program is well underway, funded by the Australian Government’s Biodiversity Fund in 2012. In the first for four years, 251 sites have been assessed and interventions have taken place at 102 of these sites; with a further 18 sites to be worked during the remaining funded period.

Works to date include grazing management, weed and pest species management and 960 ha of direct seeding on 70 sites. The sites are being monitored using 250 permanent photopoints located to track key vegetation structural changes, as well some transect counts of regeneration and seedling success (recruitment). Approximately 108 assessments, using the original proformas plus plot counts, are being conducted on a subset of key sites including untreated sites. Initial results of the grazing management and direct seeding are encouraging. Very successful seedling germination has occurred in the direct seeded lines on most of the seeded sites (although germination on some of the drier Boree sites took longer). Some sites have had additional seeding done in subsequent years to provide a mix of age classes. The seedlings have now developed to a range of heights, with some older seedlings up to 2 m high, while some seed continues to germinate. Some of the more mature plants have seeded in the last 12 months and the expectation is that a soil seed bank will now be starting to form.

As aggressive exclusion of birds from woodland and forest habitat by abundant Noisy Miners is listed as a Key Threatening Process (KTP) in NSW and the Commonwealth – culling of Noisy Miner (Manorina melanocephala) is being undertaken to benefit woodland bird populations. This is being done at a scale not attempted before. Baseline bird surveys have been conducted on 80 sites established over 70 reserves including on sites with and without Noisy Minor culling; and sites with shrubs and without shrubs within a range of vegetation types. The seasonal benchmark surveys have been undertaken on 8 occasions but because only one post-culling survey (spring) has been undertaken to date, it is premature to identify whether changes in bird populations have occurred yet. The surveys will continue till Autumn 2017.

Lessons learned. The results of works at the Coreen reserves are clearly a direct response to the manipulation of the timing and intensity of grazing pressure to reduce weed and allow rest for recovering native species. Achieving the desired grazing management required a paradigm shift for managers and clients. The close management of grazing, direct seeding and burning also relies on a high level of understanding and commitment by the TSR manager.

Acknowledgements. We thank Rick Webster for his seminal rapid assessments of TSRs in the late 1990s throughout southern NSW. Norman Wettenhall a visionary philanthropist and a friend of TSRs funded much of the early assessment work. The more recent funding provided by the Australian Government’s Biodiversity Fund. A number of LLS staff / Biosecurity officers are involved in the works, including Peter O’Shannassy, Michael Mullins, Stuart Watson and Roger Harris. Ian Davidson, Regeneration Solutions P/L is undertaking the vegetation assessments, Chris Tzaros, Birds, Bush and Beyond, is undertaking the bird surveys and Phil Humphries provided the mapping

Contact: Peter O’Shannassy, Murray Local Land Services (74 Short St Corowa NSW 2646, 0427010891 peter.o’shannassy@lls.nsw.gov.au) and Ian Davidson Regeneration Solutions P/L (15 Weir Street Wangaratta, 0429 662 759, ian@regenerationsolutions.com.au).

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

 

 

 

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.

 

 

 

 

 

 

 

 

 

 

 

 

Update on Regent Honeyeater Habitat Restoration Project (7 years on) – Lurg Hills, Victoria

Ray Thomas

Key words: Agricultural landscape, faunal recovery, community participation, seed production area

Twenty-one years of plantings in the Lurg Hills, Victoria, have seen a consolidation of the work described in the 2009 EMR feature Regent Honeyeater Habitat Restoration Project.  The priorities of the Project are to protect and restore remnants and enlarge them by add-on plantings. Together, this work has protected relatively healthy remnants by fencing; restored depleted remnants by planting or direct seeding; and revegetated open areas that had been cleared for agriculture. Other restoration activities include mistletoe removal, environmental weeding, environmental thinning; feral animal control, kangaroo reduction, nest box placement, and systematic monitoring of a range of threatened and declining woodland birds and hollow-dependent mammals.

Updated outputs since 2009. A further 540 ha of private land has now been planted (150 additional sites since 2009). This means the total area treated is now 1600ha on over 550 sites. The oldest plantings are now 19 years old and 10m high (compare to 12 years old and 6m high in 2009) (Fig 1).

The total number of seedlings planted is now approx. 620,000 seedlings compared with 385,000 in 2009. Some 280km fencing has been established compared with 190 km in 2009. Mistletoe now treated on scores of heavily infested sites

Foster's Dogleg Lane 19 yrs

Fig. 1. Ecosystem attributes developing in 19-year-old planting at Dogleg Lane (Foster’s). Note pasture grass weeds are gone, replaced by leaf litter, logs, understorey seedling recruitment, open soil areas.

Improvements in genetics and climate readiness. As reported in 2009, seed collection is carried out with regard for maximising the genetic spread of each species, to prevent inbreeding and more positively allow for evolution of the progeny as climate changes. This has meant collecting seed in neighbouring areas on similar geological terrain but deliberately widening the genetic base of our revegetation work. We are also attempting to create as broad bio-links as possible so that they are functional habitat in their own right (not just transit passages). This may allow wildlife to shift to moister areas as the country dries out. With a species richness of 35–40 plant species for each planting site, we also enable natural selection to shift the plant species dominance up or down slope as future soil moisture dictates.

2016 Update: In recent years we have engaged with geneticists from CSIRO Plant Division in Canberra, to improve the genetic health of our plantings. Many of our local plants that we assumed to be genetically healthy, have not recruited in our planting sites. For example, Common Everlasting (Chrysocephalum apiculatum) produces very little if any fertile seed each year because it is sterile to itself or its own progeny (Fig 2 video). In fragmented agricultural landscapes, it seems that many of our remnant plants have already become inbred, and it is seriously affecting fertility, form and vigor. The inbreeding level has affected fertility in this particular case, but we have several other cases where form and vigor are seriously affected as well.

Fig 2. Andie Guerin explaining the importance of collecting seed from larger populations. (Video)

Seed production area. We have now set up a seed production area (seed orchard) for about 30 local species that are ‘in trouble’, to ensure that the plants have sufficient genetic diversity to reproduce effectively and potentially adapt, should they need to as a result of a shifting climate. This will allow these populations to become self-sustaining. Each species is represented in the seed production area by propagules collected from typically10-15 different sites (up to 20kms and sometimes 50kms distant) and as many parents as we can find in each population.

We aim for at least 400 seedlings of each species, to ensure the genetic base is broad enough to have the potential for evolution in situ. The planting ratios are biased towards more from the bigger populations (that should have the best diversity), but deliberately include all the smaller populations to capture any unique genes they may have. We plant each population in separate parallel rows in the seed orchard to maximise the cross pollination and production of genetically diverse seed for future planting projects. We have noticed that the health of some of these varieties is greatly improving as a result of increasing the genetic diversity. On one site we direct-sowed Hoary Sunray, sourced from a large population, and it has since spread down the site very quickly (Fig 3).

Gary Bruce wildflower patch Orbweaver

Fig 3. Small sub-shrubs and herbaceous species are generally not planted in stage 1 of a project, as the weed levels are often too high for such small plants to succeed. These plants are only introduced in stage 2, when the weeds have diminished up to a decade later. This approach has been very successful with direct seeding and planting some of our rarer forbs.

Recruitment of Eucalypts now evident. Nearly 20 years on from the first plantings, we can report that quite a number of sites have eucalypts old enough to be flowering and seeding, and some of them are now recruiting. We are delighted that our early efforts to broaden the planting genetics are demonstrating success with such natural processes (Figs 1 and 3). Ironbark recruitment from our plantings commenced in 2014 and Red Box commenced in 2015.

Recruitment can also be seriously affected by herbivore problems, particularly rabbits. In recent years we have been undertaking careful assessments of rabbit load on a potential planting site and have gained some advantage by deploying an excavator with a ripper attached to the excavator arm. The excavator allows us to rip a warren right next to a tree trunk (in a radial direction), or work close to fence without damaging either. We’re finding this is providing a very good result. On one site we suspected there were a few warrens but it turned out to be just short of 30 warrens within 100 m of the site – each with 30-40 rabbit holes. After ripping all of those, we ended up with activity in only 2 of the warrens, which were then easily retreated.

We have had such good results with the rabbits on some sites that we are trialing planting without tree guards – it’s much more efficient on time, labour, and costs. And adjacent to bush areas, where kangaroos and wallabies are a significant threat to plantings, this process has an extra advantage. It seems that macropods learn that there is something tasty in the guards, so a guard actually attracts their attention. Our initial trials are producing some good results and given us confidence to expand our efforts with thorough rabbit control.

Faunal updates. An important objective of the project is to reinstate habitat on the more fertile soils favoured for agriculture, to create richer food resources for nectarivorous and hollow-dependent fauna including the Regent Honeyeater (Anthochaera phrygia). In 2009 the Regent Honeyeater was nationally Endangered and was thought to be reduced to around 1500 individuals. By 2015, it was thought to be reduced to 500 individuals, and so has been reclassified as Critically Endangered.

Regent Honeyeaters have turned up in recent years in gully areas where the soils are deeper, the moisture and nectar production is better, and there is a bit more density to provide cover against the effects of aggressive honeyeaters like the Noisy Miner (Manorina melanocephala). The Regent Honeyeaters have been able to remain on such sites for around for a week or more, but have not bred on the sites to date. But breeding has occurred about 15kms away on the eastern edge of our project area. Radio-tracking showed that these breeding birds were some of the captive-bred birds released at Chiltern 100km further NE, and that the birds came towards Lurg after the Chiltern Ironbarks had finished flowering. We consider it to be just a matter of time before the Regent Honeyeaters will find the many habitat sites we’ve planted on higher productivity soils in the Lurg area.

Formal monitoring of Grey-crowned Babbler (Pomatostomus temporalis temporalis) for the past last 13 years has documented a rapid rise (due to some wetter years) from 60 birds in 19 family groups to approx. 220 birds in 21 family groups. There is also exciting evidence that the endangered Brush-tailed Phascogale (Phascogale tapoatafa) is returning to the Lurg district. The distinctive shredded Stringybark nests are now found in scores of our next boxes (up to 10km from the site of our first records of 2 dead specimens in the south of our project area in the mid 1990s). This dramatic population spread is presumably a direct result of our carefully located corridor plantings that have bridged the habitat gaps all across the district.

Increased social engagement. In the last 6 years we have increased the number of visits to planting days by 50 per cent. There has been a steady growth in the number of new local landholders involved and the total number is now 160 landholders engaged, compared with 115 in 2009. Everyone we come across knows of the project and anyone new to the area hears about it from one of their neighbours. Very few people (you could count them on one hand), say they would rather not be involved. In fact we increasingly get cold calls from new people who have observed what has happened on their neighbour’s place and then phone us to say they want to be involved. It’s a positive indication that the project is part of the spirit of the area. This was further confirmed by the inclusion, of a very detailed Squirrel Glider (Petaurus norfolcensis) mural in a recent street art painting exhibition. The permanent artwork is the size of a house wall, and situated prominently in the heart of the parklands of Benalla.

Much of our work has relied heavily on volunteers, with a total of 10,344 students and 24,121 community volunteers involved over the past 21 years. City folk have fewer opportunities to be in nature, with the bushwalking clubs, university students and scouts in particular, really keen to come and roll up their sleeves.

Typically about 17 to 20 of the local schools, primary and secondary, help us with propagating the seedlings at the start of each year and then planting their own seedlings back out into the field in the winter and spring. And we are increasingly getting interest from metropolitan schools that come to the country for a week-long camp. Some of the schools even have their own permanent camps up here and they want to be involved with our hands on work too. “It’s simply part of our environmental responsibility”, is the way they express it.

Contact: Ray Thomas, Coordinator of the Regent Honeyeater Project Inc (PO Box 124, Benalla, Vic. 3672, Australia; Tel: +61 3 5761 1515. Email: ray@regenthoneater.org.au

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Seed production and direct seeding to restore grassy understorey diversity at Mount Annan, NSW.

Peter Cuneo, Jordan Scott and Katharine Catelotti

Key words: direct seeding, grassy woodland restoration, seed production areas, Cumberland Plain woodland

Need for restoring grassy diversity. The rapid spread of African Olive (Olea europaea ssp. cuspidata) in the Cumberland Plain region of western Sydney in recent decades is now a significant conservation concern (Figs 1 and 2). Cumberland Plain Woodland (CPW) is now listed at the state and federal level as a critically endangered ecological community, and African olive invasion is recognised as the greatest invasive threat to CPW, and listed under the NSW TSC Act as a Key Threatening Process.

Dense monocultures of African olive are now established at a landscape scale in western Sydney, and there has been considerable use of mechanical mulching (‘forest mowing’) to control these highly degraded CPW remnants/monocultures (Fig 3). Often only remnant trees remain, and once these dense olive infestations are controlled, land managers are faced with several years of follow up olive control, degraded native soil seedbank and a profusion of annual weeds.

The Australian Botanic Garden, Mount Annan (ABGMA) has completed over 40 hectares of mechanical control of African Olive since 2009. Recent research (Cuneo & Leishman 2015) has indicated that a ‘bottom up’ approach restoration using native grasses as an early successional stage has potential to restore these transitional landscapes and achieve a trajectory towards CPW.

Hillside African olive invasion

Fig 1. Hillside African Olive invasion

Beneath dense olive canopy

Fig 2. Nil biodiversity beneath dense African Olive canopy

Olive mulching machine

Fig 3.  Olive mulching machine

Like many landscape scale ecological restoration projects ABGMA faces a shortage of native grass seed, however a successful NSW Environmental Trust application provided the funding support to develop a 1500 sq metre native grass seed production area as part of the Australian PlantBank landscape. The key objective was to grow high quality weed free native grass seed (of known germinability) to direct sow on degraded African olive sites where the native grassy understory had been lost.

Seed production area. The seed production area was established by tubestock planting of four key local grasses, Dichelachne micrantha (Plume grass), Microlaena stipoides (Weeping meadow grass), Chloris truncata (Windmill grass) and Poa labillardieri (Tussock grass) (Figs 4 and 5). Seed was wild source collected from CPW and grasslands within ABGMA, which provides a reference vegetation type and condition to guide restoration. The seed production area which was irrigated and fenced to exclude rabbits was highly productive, even during the first summer season. Both hand and mechanical harvesting were used, and the total output over the 2014/15 summer was impressive 118 kg of seed material harvested. All seed batches were germination tested at PlantBank which indicated a total output of over 13 million viable seeds from the first harvest season.

Planting Seed prod area

Fig 4. Planting out seed production area

 

Plumegrass

Fig. 5.  Plumegrass in seed production area, almost ready for harvest

Direct seeding of grasses. Restoration challenges included large areas, profuse annual weeds and competitive olive seedlings on the transitional post-olive sites. A decision was made to focus the direct seeding across one fifth of the treatment area in a series of cultivated 2m wide strips at 8m spacing. The strips were created along contours to limit the erosive potential of the prepared areas. These seeded strips could then be managed in a similar way to surrounding cleared areas with broadleaf selective herbicide and slashing.

Seeded grass strips were prepared using a small track machine with surface tilling attachment to provide good soil/seed contact (Fig 6). Seed material (seed/stalks) were combined with compost (Fig 7) and sand and hand broadcasted. In an effort to create an ‘in situ’ seed production area and robust native grass populations, harvested grass seed was then used to high density (up to 3300 seeds/m²) direct sow a total of 5km x 2m wide strips throughout 5 hectares of cleared African olive sites at ABGMA in March 2015.

Favourable conditions during autumn 2015 resulted in excellent field germination, with established seedling densities of up to 608 seedlings/m² observed after 10 months (Fig 8). The combination of surface tilling and dense sowing rates has resulted in a dense and competitive grass layer, however some further broadleaf weed control along the strips will improve long term grass density and establishment.

These native grass strips will provide a ‘nucleus’ grass seed source for these degraded areas, maintaining soil stability, improving ecological resilience and accelerate the regeneration of these degraded areas.

Direct seeding strips

Fig 6. Direct seeding strips prepared

Mixing bulk native grass seed

Fig 7. Mixing bulk native grass seed

Seed strip established2comp

Fig 8. Seed strip established after one year

Lessons learned. Using known quality seed and achieving seed/soil contact through surface tilling was important to success, as cleared olive areas have a heavy mulch layer which limits seed contact. The use of both C3 and C4 grasses in the direct seeding mix worked well and is recommended, particularly for autumn sowing where cool season C3 can establish a quick cover followed by C4 grass establishment in summer. Some mechanical wild grass seed harvesting is also done at ABGMA, however practitioners should be aware of the risk of grassy weed contamination. Overall the project was relatively labour intensive, but some mechanisation of seed spreading could be achieved with a compost spreader. Steep terrain at ABGMA is a limiting factor for some machinery, and hand broadcasting can be a practical option.

Future directions would include scaling up the size of seed production areas, and refining mechanical harvesting techniques. Grass seed strips will be progressively managed, and seed either mechanically harvested or slashed to spread seed across the site. Once grasses are well established, the next phase will include direct seeding of CPW shrubs and trees. The well prepared and presented seed production area with mass plantings of native grasses, attracted considerable visitor interest at ABGMA and became a focus for several practitioner field days on olive control and ecological restoration.

Acknowledgements: Implementation of this NSW Environmental Trust project has relied significantly on working with industry partners, Greening Australia (Paul Gibson-Roy, Samantha Craigie, Chris Macris), Cumberland Plain Seeds (Tim Berryman) and Australian Land & Fire Management (Tom McElroy) who have bought additional technical expertise as well as on-ground implementation.

Contact person: Dr Peter Cuneo, Manager Seedbank & Restoration Research, Australian Botanic Garden, Mount Annan, NSW Australia. Locked Bag 6002, Mount Annan NSW, 2567. Email: peter.cuneo@rbgsyd.nsw.gov.au   Phone: +61 (2)46347915

Watch RegenTV Video : Seed production area

Read full EMR feature: http://onlinelibrary.wiley.com/enhanced/doi/10.1111/emr.12139

BG & CP website: https://www.rbgsyd.nsw.gov.au/Science-Conservation/Our-Work-Discoveries/Natural-Areas-Management/Restoring-test

 

 

Macquarie Island Pest Eradication Program – Impacts on vegetation and seabirds

Key Words: Subantarctic, eradication, seabirds, vegetation, restoration

Introduction. Introduced rabbits, rats and mice have caused widespread and severe ecological impacts on the native flora, fauna, geomorphology and natural landscape values of Subantarctic Macquarie Island. Major impacts include the destruction of almost half of the island’s tall tussock grassland and the depletion of keystone palatable species, a decline in the abundance and or breeding success of a range of seabird species due to habitat degradation, increased exposure to the elements and predation, as well as increased slope erosion. The Macquarie Island Pest Eradication Project is the largest eradication program for rabbits, ship rats and mice in the world.

The overall goal of the pest eradication project was to eradicate rabbits, rats and mice from Macquarie Island to enable restoration of the island’s natural ecological processes including the recovery of plant and animal communities impacted by these feral species.

Works undertaken. The Tasmania Parks and Wildlife Service developed a plan for the eradication of rabbits and rodents on Macquarie Island that was approved by the federal Minister of Environment in 2006. Following lengthy negotiations and a donation of $100,000 by the World Wildlife Fund (WWF) and Peregrine Adventures, funding of $24.6 million for the project was secured in June 2007 through a joint state and federal government agreement.

The three major components of the Macquarie Island Pest Eradication Plan after the initial planning and organisation phase were:

  • Toxic baiting of rabbits, rats and mice using aerial baiting from helicopters across the island conducted over two winters to minimise the risk of mortality for non-target seabirds. Mitigation measures were taken to reduce seabird mortality in six species after the 2010 baiting, including the introduction of calicivirus (Rabbit Haemorrhagic Disease Virus) before further baiting in May 2011 – (See Evaluation Report 2014)
  • On-ground follow-up with hunters and dogs, which was originally expected to take about three years but took seven months (2012) following the outstanding success of the calicivirus in substantially reducing rabbit numbers.
  • Five months after the last known rabbit was killed, the monitoring phase of the project commenced in April 2012 to search for any evidence of live rabbit or rodent presence on the island and continued for two years, with some 92,000 km travelled over 3 years (2011-2014).

Following two years of monitoring without any evidence of the target species, the project to eradicate rabbits and rodents from Macquarie Island was declared successful in April 2014.  A variety of established research/monitoring projects on threatened native plant species, invasive plant species, plant communities and ten species of seabirds on Macquarie Island have been used to provide biologic data on changes in abundance, distribution and condition (see Evaluation Report 2014).

Large areas of the highly palatable macquarie megadaisy are recovering from rabbit grazing Photo Kate Keifer

Figure 1. Large areas of the highly palatable macquarie megadaisy are recovering from rabbit grazing. (Photo Kate Keifer)

Results to date.

Vegetation. Vegetation recovery was well underway by 2013, when vegetation biomass on the island had increased by a factor of five to ten compared with 2011 levels.

The initial stage of vegetation recovery following rabbit eradication was a rapid increase in the biomass of the pre-existing communities. The pre-eradication vegetation was a highly modified disturbance disclimax with the majority of the lower slopes of the island dominated by Short Subantarctic Bent Grass (Agrostis magellanica), where regular soil disturbance by introduced species encouraged the establishment of herbaceous primary colonisers including willowherbs (Epilobium spp.), Subantarctic Bittercress (Cardamine corymbosa), Waterblinks (Montia fontana) and the introduced Annual Meadow Grass (Poa annua). Subantarctic Buzzy (Acaena magellanica) covered large areas. Tall Tussockgrass (Poa foliosa) was reduced to small pockets or individual plants on steep slopes, whilst the Macquarie Cabbage (Stilbocarpa polaris) was confined to very steep coastal slopes and Prickly Shieldfern (Polystichum vestitum) survived in exclosures.

More recent monitoring shows bare ground declining, with further increases in vegetation cover and successional changes. Taller/longer lived species have greatly reduced the cover of primary colonisers (mostly short lived, small herbs). The three introduced plant species on the island, all of which are primary colonisers, have fluctuated in abundance post-eradication.

Annual meadow grass has decreased markedly in abundance away from areas of seal and seabird disturbance, while Mouse-ear Chick Weed (Cerastium fontanum) and Garden Chickweed (Stellaria media) initially increased in abundance between 2011 and 2013 but have since declined.

The previously ubiquitous Subantarctic Buzzy has declined dramatically with competition from other species, while the previously less common Little Burr (Acaena minor) is now more prevalent.

The megaherbs Macquarie Cabbage and Macquarie Megadaisy (Pleurophyllum hookeri) and Tall Tussockgrass are beginning to spread and establish across the island (Figure 1). It is predicted that a combination of these species will become dominant in much of the coastal and slope vegetation over time, with Tall Tussockgrass already increasing in cover in many areas. The prickly shieldfern is expanding from a few remnant populations by recruitment or regeneration in former exclosures, as well as establishing in new locations.

Image 4 DSC_1110 cropped

Seabirds. A combined total of 2418 individual native birds were recorded as killed via primary and secondary ingestion of broadifacoum poison during the winter baiting of 2010 and 2011. These numbers are minima, since many were predated before detected and others died at sea. Kelp Gull (Larus dominicanus) sustained the largest mortality (n=989), followed by Giant Petrels (Macronectes spp; n=761), Subantarctic Skua (Catharacta skua) (n=512) and Black Duck (Anas superciliosa) (n=156). Existing monitoring programs enable the population consequences of this mortality to be evaluated for both species of giant petrel and for skua, however baseline data for gulls and ducks on Macquarie Island are lacking. The mortality event was associated with a 25-30% reduction in the breeding populations of both giant petrel species, however ongoing monitoring reassuringly shows both populations to have stabilised and appear to have resumed the increasing trajectory that they were undergoing before the mortality event. Skua were heavily impacted, with breeding numbers reduced by approximately 50% in monitored sites. There is minimal sign of recovery for this species in recent years. The response of this species to the sudden removal of a primary prey item (rabbits) and the consequent flow-on ecosystem impacts is the focus of current investigation.

With the success of Macquarie Island Pest Eradication Program, we are seeing rapid recovery in the breeding habitats of both burrow and surface nesting species. Grey Petrel (Procellaria cinerea), which re-established on Macquarie Island after the successful eradication of cats in 2000, have continued to increase and Blue Petrel (Halobaena cerulea) which were previously restricted to rat-free offshore rock-stacks, have returned to mainland Macquarie Island and continue to expand in both distribution and number. Dedicated survey effort in coming seasons will provide quantitative estimates of the response of the burrow nesting seabird assemblage to Macquarie Island Pest Eradication Program.

Lessons. Perhaps one of the most important lessons learned is the value of biological monitoring data, before during and after such an eradication program, which provides the basis for effective adaptive management as well as evaluation of success or otherwise.

The other salutatory lesson is the complex biological inter-relationships that exist and a need to more explicitly factor in the consequences of the ‘unknowns’ in associated risk assessments.

Acknowledgement. Thanks to Micah Visoiu for most recent vegetation data.

Contact. Jennie Whinam, Discipline of Geography & Spatial Sciences, University of Tasmania Jennie.Whinam@utas.edu.au; 0447 336160. Rachael Alderman, Wildlife Management Section, Department of Primary Industries, Parks, Wildlife and Environment, Rachael.Alderman@dpipwe.tas.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.

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

Andrew Sheath

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

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

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

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

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

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

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

Fig 2. Gorse distribution and density pre-burn

Fig 2. Gorse distribution and density pre-burn

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

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

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

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

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

Fig 5. Erica post control and pre-burn

Fig 5. Erica post control and pre-burn

Fig 6. Erica post-control and post-burn

Fig 6. Erica post-control and post-burn

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

Fig 7. Swamp burnt in drier conditions during autumn.

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

Follow up control work in swamp.

Fig. 8. Follow up control work in swamp.

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

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

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

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