Category Archives: Grassland/grassy understorey

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

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.

 

Reconstructing Western Sydney Grassy Woodland Understorey at Hoxton Park, Sydney, NSW

By Christopher Brogan

Purpose of the project. Endeavour Energy sought to restore a small highly disturbed Cumberland Plain Woodland bushland remnant at the West Liverpool Zone Substation at Hoxton Park, to offset 12 native trees removed to facilitate construction works at their electricity substation.

Condition of the site. The Cumberland Plain Woodland remnant was very small (approx.0 3.ha) and contained relatively healthy examples of four native trees (Grey Ironbark Eucalyptus crebra, Grey Box E. moluccana , Forest Red Gum E. tereticornis and some Paperbark Melaleuca decora). However, the native shrub and ground layer was generally absent and the soil surface was highly compacted with a low organic matter content. This was due to historic clearing for agriculture, recent clearing for the installation of electrical infrastructure and the fact that a layer of coarse fill material and asphalt had been deposited over the topsoil in some areas (probably for car parking).

Goals. As we found fragments of 3 grasses and 6 forbs remaining on site, our goals were to protect and enhance all remaining plants by ecologically sensitive weed control and planting of missing species from the Cumberland Plain Woodland community.

We had 24 months to achieve the revegetation, with performance criteria being: a survival rate of >80%; a reduction in the percentage cover weed to < 5%; and, an increase in percentage cover of the herbaceous layer to 67% – 100%.

Fig 1. Weed control included cut stump poisoning of woody weeds and high volume herbicide spraying of invasive perennial grasses.

Fig 1. Weed control included cut stump poisoning of woody weeds and high volume herbicide spraying of invasive perennial grasses. (Photo C Brogan)

Around 260 cubic metres of recycled wood waste was used to mulch to a depth of 100mm over 2,600 square metres.

Around 260 cubic metres of recycled wood waste was used to mulch to a depth of 100mm over 2,600 square metres.(Photo C.Brogan)

What we did. We identified two zones on site: Zone 1 – with capacity for assisted regeneration; and Zone 2 – without capacity for assisted regeneration. Zone 1 was treated using standard bush regeneration techniques – i.e. removal of weed to facilitate natural regeneration. Zone 2 treatments included: weed control, mulching with recycled wood waste (2,600m2 x 100mm deep); planting with 9,100 native tubestock (3-4 plants /1m2) raised from Western Sydney seed; and watering throughout the first month.

After some assisted natural regeneration and planting 9,100 native tubestock (raised from Western Sydney seed) a strong cover of native understorey was reinstated.

After some assisted natural regeneration and planting 9,100 native tubestock (raised from Western Sydney seed) a strong cover of native understorey was reinstated. (Photo. C Brogan)

The Presentation Title

Same part of the site taken before and after treatment.

Same part of the site taken before and after treatment. (C Brogan)

What advice can we offer?

  • Always check your project site to identify any fragments of native species which may be present and protect them during weed control works, particularly when spraying herbicide.
  • Use good quality tubestock of the appropriate provenance and budget for a seed collection program if the project timetable allows.
  • Never underestimate the need to water tubestock during hot months and allocate sufficient resources to watering.

Contact: Christopher Brogan, Earth Repair and Restoration Pty Ltd, PO Box 232 Panania NSW 2213. Tel: +61 (0)2 9774 3200 Email: chris@earthrepair.com.au; Web: www.earthrepair.com.au

Acknowledgement. This is summarised from a talk first presented to the symposium ‘Rebuilding Ecosystems: What are the Principles?’ Teachers’ Federation Conference Centre, November 13th, 2014, Australian Association of Bush Regenerators (AABR).

 

 

Yarrangobilly Native Seed and Straw Farm

Elizabeth MacPhee and Gabriel Wilks

Yarrangobilly Caves is a tourist destination within Kosciusko National Park (KNP), New South Wales. The Yarrangobilly Caves Wastewater Treatment Plant (WTP) has been established to treat greywater produced at the tourist centre, to stop nitrogen moving into the limestone karst system of the caves.

To optimise benefits from the WTP, the Rehabilitation team undertook the planting of locally native grass species in the discharge area, with a view to producing seed and weed-free mulch for use in the KNP Former Snowy Sites restoration program.

Effluent is initially treated using a bacterial blivet and then undergoes an ultra-violet treatment process so that it is within a “greywater” classification. It is then stored in a 200,000 litre tank and released under pressure to a discharge area. Prior to being discharged the effluent is diluted with fresh water to an average ratio of 7:3 (effluent:fresh water) in order to reduce the total nitrogen in the irrigated water to around 10 mg/L, which has been used as a threshold figure for nutrient loading. Once at the right concentration, the effluent is discharged in a large flat sedimentary rock area of about 1 ha in size.  The irrigation area in which the plant species are grown is approximately 0.5 ha.

Vegetation treatments. From 2006 to 2010, some 20,000 plants of a number of species of the grass genus Poa were planted in the discharge area of the WTP, at 50cm spacings (Fig 1).  The four main species were: Poa costiniana; P. fawcettiae, P. sieberiana and P. ensiformis; all native to KNP. Over the last 6 years, more than 300 kilos of highly viable Poa spp. seed has been collected and used in restoration works across the Park. The thatch (seed heads and cut off straw) has also been harvested and used as mulch on some of the sites.

Other species needed for rehabilitation in KNP have also been planted in the site over the last two years. Bossiaea foliosa and Lomandra longifolia have been grown for seed production and a variety of difficult to germinate shrubs have been grown to provide cutting material for propagation.

Soil sampling and soil treatments. Sampling was conducted prior to and after plant harvest to gauge the soil’s physical and nutrient status.  The samples (10cm cores of topsoil and subsoil) were sent to the Environmental and Analytical Laboratories at Charles Sturt University for analysis of Total Phosphorus and Total Nitrogen. (ammonia and nitrates as Nitrogen and phosphorus as Phosphorus (Bray)).

As early soil tests showed that pH reduced, Lime was applied to the discharge area in 2010 at 1 – 1.5 tonnes to to raise topsoil pH approximately 1 unit.

Results.

Seed and mulch production: Within the first 18 month period, nearly 100 kilos of seed was collected. To date over 300 kilos of highly viable Poa spp. seed has been collected and used in rehabilitation across the park, with the 2011/2012 harvest producing approximately 58 kilograms of seed. In the 2012-12 harvest, an estimated 288 kilograms of thatch was removed for use as mulch in restoration areas in the Park.

Soil fertility. More nitrogen and phosphorus was discharged during the 2011/2012 season than could be removed by plants season, with the native species having naturally low nutrient removal rates. Annual soil monitoring and peizometer monitoring of the ground water is keeping track of the use and movement of nitrogen in this landscape and to monitor any changes in soil chemistry.

 Suggestions for improvements:

  • Review irrigation scheduling to ensure the bulk of irrigation is occurring from November to March when nutrient uptake will be at its highest (rather than in the cooler months).
  • De-thatch the grass species at the start of spring to encourage fresh re-growth and therefore improve nutrient uptake over the spring and summer months
  • Test effluent on a regular basis to assess salt load;
  • Further treat effluent to reduce the nitrogen, phosphorous and sodium load;
  • Monitor and adjust pH as required; and
  • Reseed bare patches to maximise nutrient uptake by plants.

 In 2012 a progressive replacement planting program commenced, where sections of the oldest plants were poisoned and replaced with young plants. This continual renewal replanting will ensure the plantation remains actively growing, taking up maximum levels of nutrient and producing high quality seed and mulch.

Acknowledgements.  Funding for this project came from The Former Snowy Sites Rehabilitation project with soil and plant nutrient data provided by D.M McMahon (2008, 2012): Environmental Monitoring Use of Effluent for Irrigation, Yarrangobilly Caves, NSW. Environmental Consultants (agronomy) Wagga, Wagga.

Yarrangobilly grasses ready for harvesting

Yarrangobilly grasses ready for harvesting

The plantings are mainly four local species of Poa

The plantings are mainly four local species of Poa

West Hume Landcare Group – Taking stock, 24 years on

Judy Frankenberg

Key words: agricultural landscape restoration, community involvement, salinity, threatened species

The West Hume Landcare Group was formed in 1989 as a community response to land degradation in the area. Funding to employ a coordinator for three years was obtained in 1990. This enabled a high level of project activity in addition to tree planting, including a roadside vegetation survey, farm planning workshops, demonstration sites for ground water recharge and discharge management, and perennial pasture establishment. In the first 5 years of its existence, the group organised nearly 250 different events, attracted funding of over $500,000 and managed 17 different projects.

The second 5 years saw a period of consolidation – then, from late 1997, the employment of a full time project officer enabled  the development of a Land and Water Management Plan.  By early 2000 the Group had attracted a total of $1,000,000 in project funding over 11 years.

“Taking Charge of Recharge” was the largest project undertaken by the West Hume Landcare Group, commencing in 2001. It involved 80 properties, with a total of 170,009 local trees and shrubs planted on 370 ha.  Some 93 ha of remnant vegetation were fenced over the two years of the project. This project was the climax of a very busy 12 years of the Landcare Group’s life, during which 400,000 trees and shrubs were planted in a wide variety of projects across the landcare area – in addition to direct seeding and natural regeneration.  This revegetation had a variety of purposes, including recharge and discharge management, corridor linkages between remnants, vegetation connections specifically designed to strengthen the local (threatened) Squirrel Glider (Petaurus norfolcensis) population, and livestock shelter.

Many of the planting projects initially involved only small numbers of trees, with a low proportion of shrubs.  They were important in giving landholders confidence that tree planting was a credible farm management activity and in their ability to succeed in species selection and establishment.  The Landcare group provided a lot of support in species selection, and, as the demand for shrubs grew, the nurseries responded by increasing their availability.

Nearly all revegetation in West Hume has used local species, and as far as possible these were grown from locally sourced seed.  The diversity of shrub species used increased over the years as knowledge and availability of the local flora improved.

Roadside survey. Local knowledge was greatly increased following the roadside survey carried out by 38 landholder volunteers.  They surveyed 460 km of road, recording floristics, conservation value and causes of degradation.  A total of 111 native species were recorded, including 28 shrubs, but very few road sections had greater than 50% shrub cover.  Many of the shrubs. grasses and forbs recorded are considered rare in the landcare area.  Knowledge of the whereabouts of these small remnants has allowed seed collection and propagation of some of them in seed production areas on local properties and at the Wirraminna Environmental Centre at Burrumbuttock.  The need for this local source of seed has been emphasised by the observation that in the case of a few acacia species, local forms are different from those growing in neighbouring areas.

Landcare survey. Landholder views about the importance of vegetation was shown in a landcare survey carried out in 1999. A majority of the 60% of respondents considered that dieback of trees and the lack of shrubs, understorey and wildflowers was of concern and there was a clear concern expressed about the decline of native birds in the area.

When the “Taking Charge of Recharge” project was funded in 2001, the response of landholders was enthusiastic.  The group members were eager to take advantage of the high level of incentives available in this project to increase the scale of planting beyond that generally undertaken previously.  While the prime purpose of the funding was for recharge management, members were keen to establish local species in ecologically appropriate sites.  Ecological and botanical skills within the group were able to support the species choices.

This confidence in the value and feasibility of large revegetation projects has been continued in subsequent years when the Murray CMA has offered good incentives for large area plantings.

Contact:  Judy Frankenberg, +61 2 6026 5326, Email: judy@frankenberg.com.au

Fig 1. School student volunteers planting in block AA on ‘Warrangee’ in 1995.

Fig 1. School student volunteers planting in block AA on ‘Warrangee’ in 1995.

Fig 2. Resulting tree and shrub habitats created from 1995 planting on block AA, 2013.

Fig 2. Resulting tree and shrub habitats created from 1995 planting on block AA, 2013.

Fig 3. ‘Corridors of green’ project, 2013, planted in 1994, “Warrangee” .

Fig 3. ‘Corridors of green’ project, 2013, planted in 1994, “Warrangee” .

Regeneration of Lismore bushland cemetery, north coast NSW.

Key Words: bush regeneration, selective herbicides, transplanting, cemetery management

Since 2006, Lismore City Council’s Lismore Memorial Gardens (LMG) has been restoring and managing a 1.5ha  patch of regrowth Forest Red Gum (Eucalyptus tereticornis) grassy open forest in Goonellabah, north coast NSW – primarily for use as a bushland cemetery.  The site was part of a registered corridor for Koalas (Phascolarctos cinereus) and was in a highly weedy condition prior to the commencement of the project.  The understorey was dominated by Lantana (Lantana camara), constricting Koala movement, and most eucalypts had at least one multi-stemmed Camphor Laurel (Cinnamomum camphora) encircling it.

Bush regeneration works. In 2006 the lantana was mechanically cleared and Camphor Laurels were stem-injected with glyphosate herbicide. After woody weed removal, the ground stratum rapidly responded with a germination flush of herbaceous weeds, mainly Blue Billygoat Weed (Ageratum houstonianum), Farmers Friends (Bidens pilosa) and Broad-leaved Paspalum (Paspalum mandiocanum) although some native herbaceous species were also regenerating, particularly Basket Grass (Oplismenus aemulus), Weeping Grass (Microlaena stipoides) and Kidney Weed (Dichondra repens).

Subsequent detailed spot spraying with herbicides was undertaken; in the first few years on a monthly basis by volunteers, and more recently by a horticulture-trained LMG staff member after some workplace tuition in bush regeneration methods.

1. Resilient areas. Herbaceous weed was systematically sprayed with broad-leaf selective herbicides (Dicamba/MCPA plus surfactant) or glyphosate.  Three larger patches consolidated with native species fairly rapidly, while other areas in poorer condition colonised with fewer species or took longer to convert to native dominance.  There are now 69 species on site that  are characteristic of this ecosystem (including 8 tree species, 15 grasses, 5 sedges, 8 twiners/climbers, 5 ferns and 1 moss).  About 20 of these species have been added to the list since the start of the project and all existing species have vastly increased in cover and density. The intermittent watercourse area regenerated over time with wetland herbaceous species largely including Persicaria spp. and Cyperus exaltatus.

View of central area of the site after control of woody weed. (Camphor chipmulch was initially spread in error then later removed to allow natural regeneration)

Same area two years later, showing extensive regeneration of native grasses and forbs

2. Highly weedy edge.  Standard bush regeneration approaches over at least 2 years in an edge site proved intractable due to high weed contamination and low native richness. A trial was conducted in 2009to see if scalping and revegetation (using transplanting and direct seeding ) could reduce the amount of weed control required and improve native vegetation establishment. This involved removal by a grader of 10 cm of the weedy topsoil, with the remaining subsoil broken up with a backhoe and hand raked. Sods containing multiples of 10 species were taken from the healthier parts of the cemetery and transplanted to the raked site in mid- to late-September 2009, resulting in a total of 145 plants in each of three zones (one transplanted only, one transplanted plus direct seeded with 10 species and one neither transplanted nor seeded). Seven weeks later, when germination from the sods had occurred, it was observed that 17 species (i.e. seven more) had been transplanted (Table 1.) Very few individual transplants died.

Top10cm of weedy topsoil removed and subsoil broken up before transplanting native grass and forb sods

Subsequent monitoring found that all the two scalped and revegetated zones, while requiring monthly weed control initially, had consolidated to a very low weed state by 9 months.  There was little visible difference between them except that the seeded one contained two more species not present in the unseeded site. Within 18 months, both zones had very high cover levels of native vegetation, particularly native grasses, and weed control demand was substantially lower than adjacent edge sites treated with conventional spot spray methods alone.  The non-transplanted or seeded zone remained with low species diversity and was more exposed to weed cover.  It has since become an access track and requires higher weed control inputs than the adajacent revegetated areas.

Nine months after transplanting. With some weed control requirement, natives now well established and commencing a process of steady recolonisation

Lessons learned. The bush regeneration treatments have converted a weed-dominated site to a recognisable Forest Red Gum grassy open forest with a diverse understorey. Cemetery operations are ongoing with the condition of the bushland showing an improvement with each year. Evidence of wildlife use of the habitat is increasing. This is due to ongoing management support, continuing volunteer inputs and the deployment of staff with some training in weed and bushland management.  Although a range of highly problematic weeds (including Asian Copperburr,  Acalypha australis, Prairie Grass, Bromus uniloides, and Hairy Commelina, (Commelina bengahlensis ) were initially not adequately addressed and are now requiring additional treatment; the site is a viable demonstration site for not only restoration techniques but also the district’s grassy understorey species, once so widespread but now rarely conserved .

Contact: Tein McDonald 06 6682 2885 Email: teinm@ozemail.com.au – or Kris Whitney, Manager, Lismore Memorial Gardens, Email:  Kris.Whitney@lismore.nsw.gov.au

Research Road Restoration, Strathalbyn, South Australia

Key Words: Minimal disturbance, bush regeneration, Eucalyptus fasciculosa, volunteer, Bush For Life.

The Site: In June 1996 Trees For Life (TFL), a community based not-for-profit organisation, established a volunteer bush regeneration site (known as a Bush For Life site) on a 1.4km long, one chain wide roadside remnant on Research Road about 6km south of Strathalbyn, SA.  At this stage the road was still being used as a vehicle track.  The vegetation was a very diverse Pink Gum (Eucalyptus fasciculosa) Open woodland with occasional mallee eucalypts, a shrub understorey, sedge and herbaceous groundcover and native grasses with many locally rare and vulnerable species including the nationally vulnerable Silver Daisy-bush (Olearia pannosa ssp. pannosa ).  The largest weed problem was Bridal Creeper  (Asparagus asparagoides) which blanketed the site in the cooler, wetter months.  Other threats to the understorey diversity included broadleaf weeds typical of the dry, agricultural landscapes of the lower Murray Plains.  These weeds included Pincushion(Scabiosa atropurpurea), Wild Sage (Salvia verbenaca) and Horehound (Marrubium vulgare ).

Diverse grassy understorey found on the site

Works:  Volunteers worked on a section of the 1,400m long, one chain wide road reserve, using minimal disturbance techniques. The regenerators very carefully removed Bridal Creeper, broad leaf weeds and weed grasses; but they had to contend with the continual degradation of the remaining area. It was really only a heavily rutted, two-wheel track suitable for dry weather use only, but was subjected to indiscriminate and illegal use through all seasons, including rubbish dumping, firewood collection and “bush-bashing”.

The Alexandrina Council closed the road to motor vehicles in September 2008 and it has been allowed to recover now for 4 years.  After the road closure, discussions between Council and TFL centred on whether to leave the vehicle track to regenerate by itself or to “rip” the track to fill in the ruts and promote germination. As ripping the track was predicted to have have promoted prolific broadleaf and grassy weed establishment, particularly given the close proximity of weedy agricultural land adjacent to the linear reserve, the BFL principle of minimal disturbance prevailed and the track was left to regenerate without other intervention.

Before road closure

Results: Today there is a proliferation of native species germinating on the track, with native regeneration on the track itself far outweighing the weed regeneration.

The ruts have filled with leaf litter and have encouraged the germination of spear grasses Austrostipa sp.) and wallaby grasses(Austrodanthonia sp.). As the volunteers discover new seedlings they protected them with branches; but regeneration has become so significant that this is no longer practical.  .

Many Mallee Honey-myrtle (Melaleuca acuminata) and Dryland Tea-tree (Melaleuca lanceolata) seedlings have germinated and are thriving in bare patches.  Many other species are also germinating, including: Golden Wattle (Acacia pycnantha), Hakea Wattle (Acacia hakeoides,) Sweet Bursaria (Bursaria spinosa), eucalypts (Eucalyptus spp.), Ruby Saltbush (Enchylaena tomentosa), Climbing Saltbush ( Einadia nutans ssp. nutans), Old Man’s Beard (Clematis microphylla var. microphylla), Australian Bindweed (Convolvulus sp., and New Holland Daisy (Vittadinia sp.). Black-anther Flax-lily (Dianella revoluta, Mallee Blue-flower (Halgania cyanea,),  Rosemary Dampiera (Dampiera rosmarinifolia ) and Quandong ( Santalum acuminatum) are spreading from the sides onto the track. Areas where once a vehicle could drive have now been reduced to a narrow walking track between seedlings.

Native grasses regenerating on the road after closure

Treatment with Bridal Creeper rust (Puccinia myrsiphylli) began in 2004/2005 with wider and more intense applications applied every year from 2008. In the last couple of years rust has established itself over a large proportion of the site with very little flowering and fruiting detected during 2011.  Volunteers carefully treat plants at both ends of the site by ‘tonging’ with glyphosate  (i.e. using tongs with sponge tips as herbicide applicators) which has been very successful.  Through careful and consistent work, most of the broad-leaved weeds have been virtually removed from site, with only isolated germinations being detected and removed. One other weed – : Soursob (Oxalis pes-caprae – is prolific on site; and has yet to be targeted for control.

Rabbits re-entered the site early in 2006 and by mid-2008 had bred up to occupy 15 locations on site. They caused significant damage to the native vegetation until controlled by baiting in March 2010. The increase in native grasses in the areas treated has been significant.

Lessons learned:  Four significant events have had the greatest effect on this turnaround: the road closure, the control of rabbits, the establishment of Bridal Creeper rust and most significantly the consistent hard work of the site’s Bush For Life volunteers.

Acknowledgements:  This site is owned by the Alexandrina Council and is managed in partnership with Trees For Life who train and support volunteers through its Bush For Life program.

Contact:  Sue Bradstreet.  Regional Coordinator, Trees For Life sueb@treesforlife.org.au

Volunteers Maggie Hincks and Dean Mortimer assisting the regeneration