Category Archives: Bush regeneration

Establishment of an assisted natural regeneration model for Big Scrub sub-tropical rainforest: The Woodford Method

The results of long-term restoration at Rocky Creek Dam, have informed the development of an assisted natural regeneration model for sub-tropical rainforest known as The Woodford Method (named after the pioneering restoration work of Ralph Woodford). This method is now commonly applied across the Big Scrub region, particularly on high resilience sites and is more fully explained in Woodford (2000).

Figure 1. Remove Lantana thickets.

Figure 1. Remove Lantana thickets.

1. Winter (July-August) – refer Figure 1. In a typical area of secondary regrowth dominated by weeds such as Camphor Laurel (Cinnamomum camphora), Privet (Ligustrum sinense) and Lantana (Lantana camara), Lantana is the weed that should be killed first. Winter is the best time to do this as it is dry and it won’t reshoot when on the ground. In extensive areas, this can be done effectively by flattening thickets of Lantana with a tractor, then slashing it repeatedly to create a deep mulch, and pulling the Lantana stumps out to disturb the soil. Removing the Lantana thickets also allows access to tree weeds.

Figure 2. Kill Privet and Camphor Laurel.

Figure 2. Kill Privet and Camphor Laurel.

2. Spring (September-October) – refer Figure 2. Tree weeds such as Camphor and Privet have their biggest growth spurt, so this is a good time to give them a shot of herbicide to kill them. (Leaving the Camphor in place rather than cutting them down means that they act as ‘perch trees’ for birds and bats to land on and spread seeds through their droppings). As the Lantana, Camphor and Privet die, their leaves and branches fall to the ground and form a rich mulch on the forest floor. Light is also able to reach the forest floor, where previously it had only reached the canopy.

Spring storms come and wet the mulch, and fungal mycelium (the feeding filaments of fungi) move through the mulch and break it down, fertilising and leaving bare patches of soil where the mulch layer has totally receded.

Figure 3. Remove annual weeds.

Figure 3. Remove annual weeds.

3. Late spring / early summer (November-January) – refer Figure 3. Where you have bare soil, and there is moisture, light and an appropriate temperature, you will get seed germination. The first things to come up are annual weeds such as ‘Farmers Friends’ or ‘Cobblers Pegs’ (Bidens pilosa); ‘Blue Billy Goat Weed’ (Ageratum houstonianum); and ‘Crofton’ or ‘Mistweed’ (Ageratina spp). Annual weeds are always first to appear. They will germinate on the smell of a storm and a slight increase in temperature. Camphor and privet seedlings often come up at the same time.

When the weeds grow, they form a canopy just like the forest but at a height of one metre. In this way, weeds stop light from reaching the forest floor, inhibiting the growth of rainforest seedlings.

Therefore, it is important to remove these annual weeds and not let them go to seed. Depending on time available they are either pulled or sprayed. The experience at this site has been that the seedbank is strong enough to lose some rainforest seedlings in this initial spraying. If using herbicide, two sprays during this season generally removes all the weeds and their seeds.

Figure 4. Weed around rainforest seedlings.

Figure 4. Weed around rainforest seedlings.

4. Late summer / early autumn (February-March) – refer Figure 4.The seeds of rainforest species tend to germinate after the highest summer temperatures (sometimes up to 38 and 40 degrees) have passed. By late February and early March, daytime temperatures don’t generally go over 30 degrees, but the soil temperature and moisture is at its maximum. These conditions can produce a massive germination of rainforest seeds and those seedlings grow up very rapidly. Hand weeding is usually needed around these rainforest ‘pioneers’.

Figure 5. Enjoy the growing rainforest.

Figure 5. Enjoy the growing rainforest.

5. Early winter (May-June) – refer Figure 5. On a good site, with the best seasonal conditions, many of these rainforest seedlings will have grown to saplings above head height and can create a closed canopy within the same year. This means that less light reaches the forest floor, which reduces the amount of weed regrowth in this area – but there is still enough light for later successional rainforest seedlings to germinate, building the rainforest diversity over time.

Note: The process may be slightly different depending on the type of ‘before restoration’ landscape. Refer to Woodford (2000) for more information.

Contact: Anthony Acret,  Catchment Assets Manager, Rous Water, NSW Australia. Tel+62 2 6623 3800; Email: anthony.acret@rouswater.nsw.gov.au

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

Key Words: assisted regeneration, restoration planning, conservation

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

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

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

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

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

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

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

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

(a)NCA8n_20080502

(b)NCA8n_20080827

(c) NCA8n_20090716

(d)NCA8n_20100625

(e)NCA8n_20110630

(f)NCA8n_20151130

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

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

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

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

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

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

 

Forested wetland regeneration project, The Gap Road Woodburn, NSW

Julie-Anne Coward

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

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

Fig 1. Works zones at the Gap Road wetland

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

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

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

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

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

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

Figure 3. Sprayed Setaria prior to the burn.

Figure 3. Sprayed Setaria prior to the burn.

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

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

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

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

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

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

Tom Dexter, Jackie Miles, Deb Lenson

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

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

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

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

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

Fig 1. Mowing damage at Duesburys Beach headland

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

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

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

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

Fig 2. Dalmeny Headlands burn 2015

Fig 2. Typical burn on the headlands

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

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

Fig 2. Duesburys Point just after fire, Sept 2013

Fig 3. Duesburys Point just after burning, Sept 2013

Fig 3. Same site 11 months later, Aug 2014

Fig 4. Same site 11 months later, Aug 2014

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

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

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

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

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

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

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

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

 

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

Key words : Connectivity, Lowland Subtropical Rainforest, Threatened Species

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

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

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

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

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

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

Figure 2. September 2009: Prior to lantana control

Figure 2. September 2009: Prior to lantana control

Figure 3.  17 September 2009: Tractor crushes down lantana

Figure 3. 17 September 2009: Tractor crushes down lantana

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

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

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

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

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

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

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

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

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

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

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

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

 

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).

 

 

Twelve years of healing: Rehabilitating a willow-infested silt flat – Revegetation

Alan Lane

Key words: weed management, National Park, headwall, instability, Salix

The site: Popes Glen Creek is a small permanent stream rising in Memorial Park, Blackheath New South Wales, Australia. It flows through Popes Glen Bushland Reserve and the Greater Blue Mountains World Heritage Area (GBMWHA), joining the Grose and Hawkesbury/Nepean River systems. The upper catchment drains a significant sector of the urban township of Blackheath.

The problem: Decades of erosion from surrounding unsealed roads resulted in a 1ha silt flat forming at the headwaters of the creek and terminating in a highly incised headwall 3m high and 20m wide. Upstream, the silt flat and severely braided creek were populated by a dense forest of mature, multi-trunked specimens of Crack Willow (Salix fragilis), as well as thickets of Purple Ossier (S. purpurea), Small-leaf Privet (Ligustrum spp.), Holly (Ilex aquifolium), Cotoneaster (Cotoneaster spp.) and immature S. fragilis. There was also a ground layer of Montbretia (Crocosmia x crocosmiiflora), Blackberry (Rubus fruticosus agg), English Ivy (Hedera helix), Creeping Buttercup (Ranunculus repens) and Honeysuckle (Lonicera japonica).

This dense and complex infestation of weeds threatened to spread downstream into susceptible remote areas of the GBMWHA, where it would rapidly become extremely difficult to remove and would ultimately threaten the Grose and Hawkesbury-Nepean River systems.

Fig 1. Feb 2005 - the creek bank, dominated by weeds prior to work.

Fig 1. Feb 2005 – the creek bank, dominated by weeds prior to work.

Fig 2. Sept 2014 - same site nearly 10 years later, showing established plantings and some natural regeneration.

Fig 2. Sept 2014 – same site nearly 10 years later, showing established plantings and some natural regeneration.

Works carried out: Phase 1: 2002 – 2008  In 2002, the Pope’s Glen volunteer bushcare group, supported by Blue Mountains City Council and funding from the Urban Run-off Control Program, established trial plantings on four sites (100m2 each) to identify a limited range of local riparian and wetland species and the planting techniques best suited to revegetating and stabilising the silt flat. The species included Red-fruit Saw-sedge (Gahnia sieberiana), three teatree species (Leptospermum lanigerum, L. polygalifolium, and L. juniperinum), Broad-leaved Hakea (Hakea dactyloides), and three ferns (Blechnum nudum, B. watsii and Cyathea australis).

A 3-year grant from the Environmental Trust (2005-2008) then enabled a program of weed removal and replanting, encompassing the upstream half of the silt flat and expanding the list of plant species to about 30.

The weeds were removed progressively in a patchwork to preserve the stability of the silt. The willows were killed by stem injection and felled when dead. Over these 3 years, the volunteer group planted approximately 7000 plants and carried out approximately 1200 hours of site maintenance. This has resulted in a diverse and resilient wetland community, with high levels of plant establishment from both planting and from natural recruitment (Figs 1 and 2).

Phase 2: 2012 – 2018 At the commencement of this phase, stability of the downstream portion of the silt flat and headwall was dependent upon the integrity of the roots of the remaining dense stands of weeds. These could be removed only as part of an integrated program of works to stabilise the silt and the headwall. A second grant from the Environmental Trust (2012-2018) is enabling an integrated, 6-year program of stabilisation, restoration and revegetation to be carried out by a team of experienced contractors, using both “soft” and “hard” engineering strategies.

The volunteer group is responsible for on-going site maintenance, photography, monitoring surface water quality and water table depth and quality, and for surveying vegetation, macro-invertebrates, frogs, birds and stygofauna.

Overall results. The formerly highly degraded silted flat is now a thriving community of wetland and riparian vegetation, home to a rich diversity of small birds, dragonflies and mayflies. Frogs are beginning to populate the site. Water quality has been significantly improved, with up to 85% of faecal coliforms and 75% of nitrate-N removed in the wetland. This improves the water quality in Popes Glen Creek and reduces the pollutant load into the GBMWHA.

Fig 3. Feb 2013 - a portion of the headwall viewed from downstream. (Plunge pool approx.3m below. (Image Damon Baker www.nomadgraphics.com.au).

Fig 3. Feb 2013 – a portion of the headwall viewed from downstream. (Plunge pool approx.3m below. (Image Damon Baker http://www.nomadgraphics.com.au).

Fig 4. Nov 2014 - same site showing heavy retaining wall and spillway now constructed. (Plunge pool has been stabilised with rock armouring.)

Fig 4. Nov 2014 – same site showing heavy retaining wall and spillway now constructed. (Plunge pool has been stabilised with rock armouring.)

Lessons learned and future directions: This is an example of how an apparently overwhelming challenge can be tackled by a dedicated group of volunteers with critical mass, commitment and longevity, provided that the group has support from a body such as a local Council and that it can raise funds to employ skilled assistance as needed. It is anticipated that the ambitious program of rehabilitating the extensive and highly degraded silt flat will be completed within the life of the present grant.

Stakeholders and funding bodies: This work is supported by a grant from the Government of New South Wales through its Environmental Trust and by the Blue Mountains City Council. Unless otherwise stated, photographs have been provided by Alan Lane and Paul Vale.

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

Directly transplanting of native monocots from donor areas to suitable reconstruction sites

By Edgar Freimanis

Key words: urban bushland restoration, site remediation, direct return topsoil, plant salvage, transplanting.

Introduction: As a bush regeneration contractor often working adjacent to development sites in the Sydney Region it occurred to me that plants and topsoil earmarked for destruction at a development site could be salvaged and translocated to improve results in nearby or similar restoration areas. Monocots lend themselves to this process due to their comparatively shallow, fibrous and stoloniferous root systems that have adapted to regrowing after disturbance.

Works undertaken and results. Over the years our bush regeneration contract team has translocated monocots at a range of project sites where natural regeneration potential is very low. Typically this technique accompanies our more conventional planting of nursery grown tree and shrub tubestock in these areas. The soils in these recipient areas are usually similar to those of the donor sites from where they were sourced. If weed management is needed, the recipient sites are typically weeded before transplanting takes place. We use hand tools such as shovels to dig-up variable sized sections of mostly native grasses and some other native monocotyledonous plant sods from areas that have been designated for development and other similar authorised clearing.

The sods are placed into plastic trays, moved and directly transplanted into parts of adjoining bushland conservation areas that have been designated for reconstruction planting. The transplants can be placed within recipient sites at similar densities to grassy ground layer tubestock plantings, (e.g. at densities of between 1-4-plants per m2, or more) or laid out like turf in continuous sections,

Plant establishment aids such as water retention crystals and fertilisers are also applied to each transplant at planting to assist with plant survival and establishment. The transplants are watered-in initially and on subsequent occasions, depending on prevailing soil moisture conditions, project resources and project timing.

Ongoing follow-up bush regeneration weeding is typically undertaken in the recipient sites, as required. (Fig 1). Monitoring has been confined to ‘before and after’ photo documentation, as shown in the following examples.

Figure 1. A sod of the native grass Entolasia stricta being transplanted at 4 plants/m2 into the old driveway at the Tuckwell Road. (Photo: Ecohort)

Figure 1. A sod of the native grass Entolasia stricta being transplanted at 4 plants/m2 into the old driveway at the Tuckwell Road. (Photo: Ecohort)

1. Tuckwell Road, Castle Hill Shale Sandstone Transition Forest and Sydney Turpentine Ironbark Forest Regeneration and Reconstruction of low residence sections. The recipient site was a rehabilitated old bitumen driveway within an estimated 0.40-hecatre bushland conservation and restoration area Native grasses and other monocots were transplanted from a bushland area that was being cleared for associated road widening works at a density of four plants/m2. (Figs 2 and 3).

Figure 2. Tuckwell Road ‘before’ (note: exotic plants already removed). (Photo: Ecohort)

Figure 2. Tuckwell Road ‘before’ (note: exotic plants already removed). (Photo: Ecohort)

Figure 3. Tuckwell road about 2-years later showing transplanted native monocots and planted native shrubs. (Photo: Ecohort)

Figure 3. Tuckwell road about 2-years later showing transplanted native monocots and planted native shrubs. (Photo: Ecohort)

2. Kellyville (Cumberland Plain Woodland site). The recipient site consisted of an edge of a bushland conservation area, that was subject to earthworks associated with a retirement village development. The recipient site’s soils were ripped to alleviate compaction and topsoiled with local clay-based topsoil. Native grass sods were transplanted from donor areas that were located within the approved development footprint area adjoining the bushland conservation area. The sods were cut into 200-300mm sections and placed in close proximity to on-another, not too dissimilar to a jig-saw puzzle or hand cut turf, to make a continuous grassy layer, with minimal gaps between transplanted sods. The transplanted sods were lightly filled and top-dressed with local topsoil to fill and level out any gaps between the sods, and then trimmed to surrounding ground levels and watered-in well. (Figs 4 and 5)

Figure 4. Native grasses being transplanted, very close together like turf sods at Kellyville. (Photo: Ecohort)

Figure 4. Native grasses being transplanted, very close together like turf sods at Kellyville. (Photo: Ecohort)

Figure 5. Same Kellyvillle site about a year later. (Photo: Ecohort)

Figure 5. Same Kellyvillle site about a year later. (Photo: Ecohort)

3.Spinifex transplanting on coastal sand dunes. In this project the rhizomous native grass sprinfex was transplanted into dunes from nearby areas at Corrimal Beach in the Wollongong local government area, as a part of works associated with Council’s 2013 Dune Management Implementation Plan. The spinifex transplanting works were undertaken in conjunction with weed control and tubestock reconstruction planting works.(Figs 6 and 7)

Figure 6. Spinifex being transplanted into a section of dune at 2-4-plants per m2. (Photo: Ecohort)

Figure 6. Spinifex being transplanted into a section of dune at 2-4-plants per m2. (Photo: Ecohort)

Figure 7. Section of spinifex that has established from previous transplanting. (Photo: Ecohort)

Figure 7. Section of spinifex that has established from previous transplanting. (Photo: Ecohort)

Benefits and characteristics of direct transplanting include:

  • Reduction of lengthy plant propagation and seed collection phases;
  • Avoidance of seed maturity restrictions and clashes with project construction phases;
  • Guaranteed achievement of local provenance material;
  • Ability to obtain species that are difficult to propagate or collect seed from;
  • Potential inclusion of other plant species from donor to recipient sites (translocated as seed in the soil of transplanted sods);
  • Achievement of similar densities to tubestock planting or turf-laying;
  • Ease of implementation (transplanting monocots is a technique that has been long-practiced by bush regenerators, gardeners and horticulturists);
  • Ability to conduct the treatments on a small scale using hand tools, or large scale using heavy machinery.

Barriers and challenges to direct transplanting include:

  • Timing/gaining consent difficulties relating to compatibility of works between donor and recipient sites;
  • Convincing consent authorities of the efficacy of this method;
  • Technical issues: proximity of donor and recipient sites;
  • Cost, (including maintenance and watering) which can be higher than other methods;
  • Difficulty in transplanting some monocots;
  • Potential for soil pathogen spread.

Acknowledgements:  This summary was originally presented to the November 2014 Symposium ‘Rebuilding Ecosystems’ held at the Teachers’ Federation Conference Centre, Sydney by the Australian Association of Bush Regenerators (AABR)

Contact: Edgar Freimanis, Ecohort, ( PO Box 6540 Rouse Hill NSW Australia 2156 Tel: +61 418 162-970 Email: ed @ecohort.com)

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).

Plant communities of seasonal clay-based wetlands of south-west Australia: weeds, fire and regeneration

Kate Brown and Grazyna Paczkowska

Key words: regeneration, fire, seasonal wetlands

 While the majority of seasonal wetlands in south-west Australia are connected to regional ground water, some found on clay substrates rely solely on rainwater to fill. These seasonal clay-based wetlands fill with winter rains and are characterised by temporally overlapping suites of annual and perennial herbs that flower and set seed as the wetlands dry through spring. Over summer the clay substrates dry to impervious pans. The seasonal clay-based wetlands of south-west Australia comprise a flora of over 600 species, of which at least 50% are annual or perennial herbs, 16 occur only on the clay-pans and many are rare or restricted.

These ecological communities are amongst the most threatened in Western Australia and have recently been listed under the Commonwealth Environmental Protection and Biodiversity Conservation Act as critically endangered. Over 90% have been cleared for agriculture and urban development and weed invasion is a major threat to those that remain. South African geophytes are serious weeds within these communities and Watsonia (Watsonia meriana var. bulbillifera) in particular can form dense monocultures and displace the herbaceous understorey.

Watsonia invading  a seasonal clay-based wetland

Watsonia invading a seasonal clay-based wetland

Regeneration following weed control and fire.  We investigated the capacity of the plant community of such a wetland to regenerate following removal of Watsonia, and the role of fire in the restoration process.

 Our study site, Meelon Nature Reserve, is a remnant clay-based wetland on the eastern side of the Swan Coastal Plain 200 km south of Perth. A series of transects were established in August 2005 and regeneration of plant community following Watsonia control and then unplanned fire was monitored until September 2011 (Table 1).

 Table 1: Six years of monitoring regeneration of a seasonal wetland at Meelon Nature Reserve

August 2005 Thirty 1m x 1m  quadrats established along five 30m transects in the wetlands where Watsonia was estimated to average greater that 75% cover.
September 2005 Cover ( modified Braun Blaquet) recorded for all native and introduced taxa and then Watsonia treated with the herbicide 2-2DPA (10g/L) + the penentrant Pulse® (2.5 mL/L).
September 2006 Cover recorded for all native and introduced taxa and then Watsonia treatment reapplied.
February 2007 Unplanned wild fire burnt across the study site.
September 2007  each year until September 2011 Cover recorded for all native and introduced taxa and then any Watsonia treated.

Analysis of similarity (ANOSIM) was undertaken to determine if there was significant change in species cover and composition from before Watsonia control to six years following the initial treatment. A  SIMPER analysis was used to ascertain the contribution of each species to any changes between monitoring years (Clarke & Gorley 2006).

Results. In the first year of the control program, a 97% reduction in the cover of Watsonia was recorded, but was associated with no significant change in the diversity or abundance of native flora. In February 2007, 18 months after the initial control program, an unplanned summer wildfire burnt through the reserve. In September 2007 monitoring revealed a significant increase in cover and diversity of native species in the treatment areas. Some species such as the Dichopogon preissii had not been recorded before the fire, others, such as the native sedges, Cyathochaeta avenacea and Chorizandra enodis increased greatly in cover following the fire. At the same time there was no resprouting of Watsonia or recruitment from cormels or seed.

Six years after the initial treatment the native sedges and rushes continue to increase in cover, the dominant native shrub Viminaria juncea is increasing, Eucalyptus wandoo seedlings are recruiting into the site and native grasses and geophytes are increasing in cover. The indications are that plant communities of the seasonal clay-based wetlands of south-west Australia have the capacity to recover following major weed invasion and that fire can play a role in the restoration process.

Table 2. Species that contributed to 90% of the significant change in cover and composition of species between 2005 and 2011.

 

2005

2011

Species

Average abundance (% cover)

Average abundance (% cover)

Cyathochaeta avenacea

10.0

23.5

Chorizandra enodis

2.3

15.7

Viminaria juncea

2.1

15.4

Caesia micrantha

2.6

2.7

Briza sp. Meelon

3.1

2.0

Eucalyptus wandoo

0.0

3.0

Austrodanthonia acerosa

0.4

1.8

Hypoxis occidentalis

0.0

1.9

Lepidosperma sp. WT2Q5 Meelon

0.1

1.3

Meeboldina sp. MU3 Meelon 2011

0.2

1.4

Dichopogon preissii

0.0

1.3

Drosera rosulata

1.5

0.2

Contact: Kate Brown, Ecologist, Swan Region. Department of Environment and Conservation, PO Box, 1167 Bentley Delivery Centre, WA, 6983. Email: kate.brown@dec.wa.gov.au

Chorizandra enodis

Chorizandra enodis

Dichopogon preissii

Dichopogon preissii

Hypoxis occidentalis

Hypoxis occidentalis

Macquarie University – Turpentine/Ironbark forest Regeneration

John Macris 

Key words: Bush Regeneration, Privets, Pittosporum, in-situ conservation.

Less than 5% of the original extent of Turpentine/Ironbark forest of the Sydney Basin Bioregion remains and so this forest type is listed is listed as critically endangered under the Commonwealth EPBC Act. Weed management and rehabilitation of remnants are priority conservation actions under the Act.

A 3.5 ha remnant of Turpentine/Ironbark forest located on the Macquarie University Campus has been the focus of a bush regeneration program that commenced in 2010.  Prior to the works, the site was variable in condition, with a core area near a watercourse having relatively high species diversity including Blackthorn (Bursaria spinosa) and the rare shrub Epacris purpurascens, while edges of this area contained a diversity of weed species.  An upslope area was more highly disturbed as it had been used as a breeding enclosure for research into rare rock wallabies until around 2005.

Works to date. Commencing in Autumn 2010, contract bush regeneration works included culling of the over-represented native Sweet Pittosporum (Pittosporum undulatum) in the core area, and removal of invasive weeds, principally a dense mid-story of the woody weeds Large-leaved Privet (Ligustrum lucidum) and Small-leaved Privet (L. sinense) throughout the treatment area.  Any large Privet logs were retained as habitat. Pampas Grass was removed from around the perimeter and, in a few places, Lantana  (Lantana camara) was also removed, although some has been retained as an interim small bird habitat in a few locations. Follow up work has mainly focused on a range of herbaceous weeds including Ehrhardta (Ehrhardta erecta), and gradual exhaustion from the seed bank of the problem woody weed species.

Results Prior to works, we estimated that about 10% of remnant was in relatively good condition.  About 2.5 years on, we now estimate that about 15% – 20% of the area is now in a resilient condition. Native species regenerating include a range of native grasses and forbs including Blady Grass (Imperata cylindrica), Basket Grass (Oplismenus aemulus), Weeping Grass (Microlaena stipoides), Tufted Hedgehog Grass (Echinopogon caespitosus),Blue Flax Lily (Dianella caerulea), Plume Grass (Dichelachne sp.), Finger Grass (Digitaria parviflora) Bordered Panic Grass (Entolasia marginata), Pastel Flower (Pseuderanthemum variabile) and Kidney Weed (Dichondra repens). Tree saplings including Turpentine (Syncarpia glomulifera) and Smooth-barked Apple (Angophora costata) have been uncovered and are developing in height. The colonizing shrub Kangaroo Apple Solanum aviculare has rapidly developed a rudimentary native mid story in the areas cleared of dense Privet.

Woody weed domination of the understorey before the works commenced

Same view 2years later (2012) showing ground stratum regeneration

Lessons learned. To create a robust weed buffer to the regeneration area, we decided it was important to start work in upslope areas, even though they were disturbed by the previous animal research enclosure (e.g. artificial soil profiles).  Due to same competing uses, such areas have been challenging stablise against weed resurgence, but a management edge is being established gradually.

Acknowledgements.  Sixty per cent of the first 15 months funding for the project was provided by Sydney Metropolitan CMA through their Saving Sydney’s Biodiversity Program with the rest covered by the University.  Subsequent work has been funded under Macquarie University’s Biodiversity restoration programs. Warren Jack from the contractor Sydney Bush Regeneration Company contributed much of the above species list of ground layer regeneration.

Contact: John Macris, Macquarie University. john.macris@mq.edu.au Tel: +61 (0)2 9850 4103