Category Archives: Weed issues & solutions

Facilitated natural regeneration in the ‘Middle clearing (Setaria plots)’ of Minyumai Indigenous Protected Area, The Gap NSW

Posted on 3 November 2023 by | Comments Off on Facilitated natural regeneration in the ‘Middle clearing (Setaria plots)’ of Minyumai Indigenous Protected Area, The Gap NSW

Minyumai Rangers

Figure 1. Aerial view of the Setaria-dominated clearing at Minyuma IPA prior to restoration work . The trial area arrowed is the location of the preliminary trial of herbiciding plus fire followed by regular spot spraying of weed regrowth. The project was then expanded to much of clearing to the left of the artificial drain running through the centre of the site (Photo Minyuma IPA)

Introduction. ‘Minyumai’ is an approx. 2000ha property owned by Minyumai Landholding Aboriginal Corporation (MLHAC) and managed by the MLAC board and the Minyumai Rangers. The property is located on the far north coast of NSW, adjacent to Bundjalung National Park and Tabbimoble Nature Reserve and was dedicated as an Indigenous Protected Area (IPA) in 2011. 

The property is largely comprised of native ecosystems, including five Endangered Ecological Communities (EECs), however it has a history of grazing in largely three sizeable clearings.  The largest and most degraded of these clearings (the ‘middle clearing’) (Figs. 1 and 2) became known to the Rangers as the ‘Setaria plots’ as it was almost completely devoid of trees, was dominated by the introduced pasture grass Setaria (Setaria sphacelata) and was subsequently divided into multiple plots for treatment and monitoring.

Figure 2. Closer view of the density and cover of Setaria at the site prior to treatment. (Photo Minyuma IPA)

The purpose of the work in the Setaria plots is to convert the vegetation from weed dominance to dominance by native species of the site’s prior ‘Swamp sclerophyll forest on coastal floodplains’ EEC. The project started in 2014 and is an ongoing part of the Ranger’s regular works program. 

Works undertaken. After a successful trial sponsored by Firesticks in an adjacent area, a facilitated natural regeneration approach was adopted in the Setaria plots, supplemented by some tree planting. While there were little or no above-ground natives evident among the mature Setaria at the start of the project (Fig 2), the Firesticks trial showed that the use of fire followed by precision weed spraying would result in at least some regeneration of native ground covers from the soil seed bank.

Figure 3. Firebreaks were installed at the site prior to spraying and burning and remain maintained to allow for ongoing use of fire during over time should it prove beneficial. (Photo Minyuma IPA)
Figure 4. Minyumai Rangers and visitors from a neighbouring IPA running a burn on the site. (Photo Minyuma IPA)

The plot-by-plot approach subsequently adopted involved creating firebreaks, overspraying the mature setaria with 1% glyphosate and subsequent burning of the dried weed biomass (Figs 3 and 4).  Subsequent follow-up spot-spraying was then systematically and regularly carried out.

Monitoring.  The project offered an opportunity to separate and compare burn and spray treatments with spray-only treatments – i.e.  all plots (except untreated controls) were subjected to systematic weed management but some were additionally burnt.  Species counts and cover was measured at 2 years of age and again at 4 years of age – with the ground stratum monitored using 15 quadrats (7 burn+spray, 6 spray only and 3 controls) and woody cover monitored using 18  (20m) transects (line intercepts).

Figure 5. Photopoint monitoring showing changes at the site over a 3 year period showing treatments and gradual regeneration of natives. (Photos Minyuma IPA)

Results to date.  While the initial follow up treatments revealed extensive weed, this rapidly transitioned to native dominance over time (Fig 5) and with fairly rigorous herbicide treatment of all weed by the Rangers.  The site developed high levels of cover within 18 months. A total of  37 native species were recorded over the four years (including 5 trees, 2 shrubs,  1 vine, 18 forbs, 7 sedges and 4 grasses) .  A total of 26 weed species (1 shrub, 14 forbs, 2 sedges and 9 grasses) occurred and while weed cover reduced over time ) most species of weed remained present in the system.  

The quadrat data showed that the fire plus spot-spraying treatment resulted in improved native cover in the ground stratum (scoring an average of 3.38 on a 5 level cover scale)  compared to spot-spraying alone (scoring an average of 2.17 on the 5-level cover scale) with the controls remaining in the lowest cover level.

Transect monitoring of woody species cover over time showed a significant increase in tree cover after both fire plus spray (n=5)  and spray alone (n=9) treatments compared to the untreated controls (n=4) but there was no significant difference between the burn plus spray and spray only  treatments, which is understandable as none of the tree species form soil seed banks.

Figure 6.  Drone photo of the same quadrats from the air in August 2023, nine years after the work commenced. The dense green tree growth in the middle of the photo is all regrowth on the treated plots. Between this area and the intact Paperbark forest in the further distance there is a band of untreated land still dominated by Setaria and without native colonisation. (Note the Eucalypt circled is the same Eucalypt in the right hand background of the photos in Figure 5.)   (Photo G. Little)

Changes over time. The sedges, which were initially abundant in the understorey,  became less abundant over the two readings. Native grasses were initially far less common but increased over time, and 10 years on are still far less prevalent than sedges, which makes sense considering the wetland nature of the site.

Some  forbs, such as Buttercups (Ranunculus spp.), Gotu Kola (Centella asiatica), Pennyworts (Hydryocotyle spp.), Kidney Weed (Dichondra repens) and Native St Johns Wort (Hypericum perforatum) became frequent or abundant and remained so over the monitoring period. while other forbs such as Grass Lily (Murdannia graminea), Ludwigia (Ludwigia and Native Bluebell (Wahlenbergia sp.) remained uncommon or even rare.

Over the 10 years since the project began, the tree species Swamp Box (Lophosptemon suaveolens), Swamp Oak (Casuarina glauca) and Broad-leaved Paperbark (Melaleuca quinquinervia) have all become markedly more abundant over time through colonisation from the surrounding forest (Fig. 6) – with natural regeneration far outweighing any tree planting efforts made at the start of the project.  Forest Red Gum (Eucalyptus tereticornis) did not however increase from the remnant tree on site nor did planted seedlings of this species survive.   

Lessons learned and future directions.  When comparing the treated areas with untreated areas it is clear that the native tree colonisaton is confined to the treated areas. Although the treated areas developed high native herbaceous cover it is likely that the open niches created by the weed control and fire allowed colonisation by trees, while the dense Setaria cover prevented regrowth. 

A major challenge has been the presence of wild cattle on the property that have proved resistant to capture. This required electric fencing of the site for some years to avoid damage to plantings, although natural regeneration has now overtaken the plantings.

Critical to success was rigorous follow up prior to the weed reseeding.  Complete avoidance of reseeding was not always possible due to funding limitations or personnel changes. This has resulted in some reinvasion of Setaria in some of the plots, although the Rangers continue to manage the site well. 

As the mown firebreaks are still in place, there is potential for cool fire to be reintroduced into the site (followed by further weed control) should this be considered ecologically beneficial.  The site may also benefit from a project (being conducted in collaboration with Nature Glenelg Trust) to fill in the artificial drain visible in Fig 1.

Stakeholders and Funding bodies.  We acknowledge the valuable contributions of all the Minyumai IPA Rangers, particularly the early leadership of Minyumai Rangers, Daniel Gomes, Justin Gomes and Belinda Gomes. The Commonwealth Government’s IPA program funded the delivery of biodiversity management services by MLHAC, and funding and advice for the fire trials was provided by the NSW Nature Conservation Council’s  Firesticks initiative, with advice from Oliver Costello and Richard Brittingham. Tein McDonald advised on techniques and monitoring and Andrew Johnston provided training for the Minyumai Rangers in the first years of the project.

Contact: Mary Wilson, Minyumai Land Holding Aboriginal Corporation. Email: <admin@minyumai.org.au>

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Posted in agricultural lands, Assisted regeneration, Bush regeneration, Fire Ecology & Management, Indigenous land & sea management, New South Wales, Restoration & management theory, Techniques & methodology, Threatened species & communities, Weed issues & solutions, Wetland

Eradicating weeds along the Tasmanian Wilderness World Heritage Area coastline

Posted on 21 October 2023 by | Comments Off on Eradicating weeds along the Tasmanian Wilderness World Heritage Area coastline

Jon Marsden-Smedley

Figure 1. The project supports multiple bird species including the vulnerable (a) Hooded Plover, (b) Australian Pied Oystercatcher, (c) Sooty Oystercatcher and (c) the critically endangered Orange-bellied Parrot. (Photos J. Marsden-Smedley)

Introduction. The Tasmanian Wilderness World Heritage Area (TWWHA) in the southwest of Tasmania is an important area for conservation. The coastline of this region has high natural integrity and is a major stronghold for a number of shore-nesting and feeding birds including the vulnerable Hooded Plover (Thinornis cucullatus), Australian Pied Oystercatcher (Haematopus longirostris), Sooty Oystercatcher (Haematopus fuliginosus) and the critically endangered Orange-bellied Parrot (Neophema chrysogaster) during its migration (Fig. 1). Three ecosystem-transforming weed species: Sea Spurge (Euphorbia paralias), Marram Grass (Ammophila arenaria) and Blackberry (Rubus fruticosus aggregate) have the potential to transform the coastline’s geomorphic structure and have been identified as major threats to environmental and cultural value. It is estimated that about 425 km of the 850 km coastline in the TWWHA is susceptible to Sea Spurge and / or Marram Grass invasion.

The WildCare volunteer group SPRATS (Sea sPurge Remote Area TeamS) has been undertaking annual weed management works along the TWWHA coastline between Cape Sorell (Macquarie Harbour) and Cockle Creek since 2006 (Fig. 1). SPRATS is a self-managing volunteer group working in partnership with the Tasmanian Parks and Wildlife Service (PWS). The primary goal of the program is to initially control and then eradicate Sea Spurge and Marram Grass from the coastline (Figs 2-4). The secondary goal is to eradicate any Blackberry infestations found and monitor for other weeds.

Figure 2. The SPRATS work area.

Logistics. The SPRATS weeding program has divided the coastline into eight sectors. At the start of each weeding season, detailed maps are prepared showing weeding sites, campsites and walking routes. These data are uploaded into GPS units so that all groups can efficiently and easily locate previously recorded weed sites, campsites and walking routes. Teams of SPRATS volunteers walk each section of the coastline of the TWWHA annually. While undertaking weed control and monitoring, volunteers also record information on rare and threatened shorebird species, assist with research into the ecology of the region (e.g., collection of Tasmanian Devil scats for genetic analysis), record the location of Aboriginal cultural sites (e.g., petroglyphs, stone arrangements, middens and hut sites) and the usage of the area by other groups (e.g., quad bike riders).

Works undertaken. In the first three years of the program, weeding efforts were concentrated in the southernmost susceptible areas. Once these Sea Spurge infestations had been given an initial knock-down, efforts moved to very large infestations along 45 km of coast south of Cape Sorell. Work then expanded to include about 160 km of coastline in Macquarie Harbour.

Trials were conducted in 2009-2010 to compare both the kill rates of target species and impacts on non-target species of different herbicide treatments. These trials identified glyphosate mixed with Pulse® as the best herbicide treatment for Sea Spurge.

Different strategies have been utilised at different stages of the program. Heli-spraying operations have been used to knock down very large Sea Spurge infestations (i.e., infestations of > 250,000 plants) and the subsequent massive seed germination event. Two rounds of heli-spraying reduced the number of Sea Spurge plants by 90% and enabled subsequent hand weeding. The optimum technique identified for treating Marram Grass was to spot spray with Haloxyfop-R methyl ester and penetrant. This is followed up by hand weeding once weed densities are reduced.

A feature of the SPRATS work program is collection of geo-referenced data on all weeds removed,  along with targeted research into the most effective treatment methods. These data are used to demonstrate work effectiveness, plan annual work programs and report back to the PWS and other funding bodies.

A major development in the past two seasons has been testing and spreading the Sea Spurge biocontrol recently developed by the CSIRO. This biocontrol has the potential to provide a long term solution to the issues associated with Sea Spurge. From 2006 to 2022-23, 8504 work days have been completed, most of which has been volunteer effort.

Figure 3. A SPRATS volunteer standing in a patch of Sea Spurge at the Sassy Creek site in 2007. (Photo J. Marsden-Smedley)

Figure 4. The Sassy Creek site in 2021. (Photo J. Marsden-Smedley)

Results to date. Prior to the start of the program it was estimated that the TWWHA region contained about 11.1 million Sea Spurge plants and about 124 000 Marram Grass clumps located in over 700 sites. By 2022-2023 weeds had been mapped from over 850 sites, made up of about 700 Sea Spurge, 150 Marram Grass, four Blackberry, three Great Mullein and one Slender Thistle. To date the SPRATS program has removed over 14.4 million Sea Spurge plants (about 99.7%). In the 2022-2023 weeding season about 2795 clumps of Marram Grass were sprayed representing a 98% reduction on the pre-SPRATS number of marram grass clumps. The region’s known blackberry infestations have been eradicated.

Challenges. A major challenge is missed Sea Spurge sites. In its second year of growth, Sea Spurge produces a large number of seeds which then germinate or replenish seed banks. Seedlings from these reactivated sites are responsible for between a third and half of Sea Spurge plants treated and the rate at which SPRATS is reducing the number of Sea Spurge is slowing. It appears likely that there are an increasing number of Sea Spurge seeds washing in from very large infestations to the north of the TWWHA and also along the east coast of Tasmania. If the Sea Spurge biocontrol is found to be effective, this issue should be addressed by large scale spreading of the biocontrol agent which should reduce these very large infestations. It may also be necessary to do targeted releases of the biocontrol within the TWWHA.  

In the early years of SPRATS operations, treating Marram Grass was rated as a lower priority than Sea Spurge. Marram Grass identification and weeding is also slower, more laborious and difficult than sea spurge weeding. Marram Grass weeding involves spraying, wiping of individual leaves with herbicide or digging out entire clumps. In recent seasons, improved training in Marram Grass identification and the use of the monocotyledon specific herbicides has resulted in a significant increase in the rate of Marram Grass removal.

Stakeholders and Funding bodies:  The SPRATS program has been supported by theTasmanian Parks and Wildlife Service, WildCare, and in the early part of the project, the Australian  government’s Caring for Country program.

Contact information: Jon Marsden-Smedley, SPRATS (M) 0456 992 201 (E) jon.marsdensmedley@gmail.com  / sprats.tas@gmail.com

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Posted in Assisted regeneration, Coastal & marine, Community involvement, Fauna & habitat, Tasmania, Techniques & methodology, Threatened species & communities, Weed issues & solutions

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Shorebird habitat restoration in the Hunter Wetlands National Park

Posted on 25 August 2023 by | Comments Off on Shorebird habitat restoration in the Hunter Wetlands National Park

By Tom Clarke

Figure 1. Contractors felling mangrove trees to restore migratory shorebird habitat structure at Stockton Sandspit.

Introduction. Thirty-seven species of migratory shorebirds regularly visit Australia, with all but one spending up to 6 months of each year here. Globally, populations of some migratory shorebirds have declined by 80% over the last 30 years largely due to habitat destruction and disturbance along the East Asian-Australasian Flyway. Within Australia, degradation of feeding and roosting habitats and disturbance are the major threats. Shorebirds need access to safe roosting places. Typically, a favoured roost is close to feeding areas, has a wide-open space and a clear view of the water. A clear view is needed for predator avoidance. A major issue for shorebirds in the Hunter Estuary, indeed for the entire flyway, is having access to several roosts so that alternative sites are available when conditions and levels of disturbance become intolerable at the preferred roost.

In the late 1990s it became obvious that vegetation encroachment was degrading major roost sites in the Hunter Estuary. Of particular concern was the viability of Stockton Sandspit, a shorebird roost site of national importance. Mangrove encroachment along the beachfront was creating a wall of vegetation and effectively blocking the view of the water. Woody weeds were also encroaching on the roost area resulting in a large decline in shorebird numbers using the roost site.

Mangrove encroachment has been documented in several estuaries along the east coast of Australia. Halting encroachment is not an option but managing specific areas that are important for shorebirds is achievable. This project involves the removal of mangroves adjacent to favoured roosting sites to maintain low, open spaces with a clear view of the water, with the intent of maintaining the sites  for shorebirds as long as they keep turning up. The potential recovery of coastal saltmarsh in these sites is an added bonus as saltmarsh is an endangered ecological community.

Figure 2.  Main shorebird habitat restoration sites in Hunter Wetlands National Park.

Works undertaken. Mangroves are normally protected vegetation by law. After it was agreed by various stakeholders that mangroves should be cleared from Stockton Sandspit, a permit to remove mangroves was applied for from Department of Primary Industries (Fisheries). The initial permit allowed for the removal of mature mangroves from an area of less than 1 hectare. This primary work was carried out by contractors (Fig. 1). The funding agreement required matching volunteer effort. Initially, volunteer work involved Hunter Bird Observer’s Club (HBOC) monitoring the shorebirds, but this was quickly augmented by on-ground work to remove woody weeds (including Lantana Lantana camara, Bitou Bush Chysanthemoides monilifera ssp. rotundata and Telegraph Weed Heterotheca grandiflora) and reduce the density of native shrubs (including Acacia spp, Banksia spp. and Leptospermum spp.) from the roost area. Weeding also aimed to remove exotic rushes from a small area of saltmarsh. Following initial success, other shorebird roost sites in the Hunter Estuary with similar threats were added to the program (Fig. 2). These additional areas were selected using data from the shorebird monitoring being conducted by HBOC. At each site, an initial primary effort by contractors is followed up by HBOC volunteers and others. The project has been running continuously since 2002 and represents the HBOC commitment to caring for these endangered birds.

Over 10,900 volunteer hours has been accrued to date through the efforts of over 480 persons and the program is ongoing. Today, the project maintains nearly 150 hectares of shorebird habitat in Hunter Wetlands National Park. From March through to July each year, a program of works is scheduled to take advantage of favourable tides to access work areas. These cooler months are better for working in exposed areas and are when the population of migratory shorebirds is at its lowest. Removal of mangrove seedlings takes up most of the ongoing volunteer effort (Figs 3-6). The level of recruitment of mangrove seedlings varies from year to year and site to site. Factors such as tide height, wind direction and flood levels at the time of seed-drop affect the distribution of the seeds. Seed-drop usually occurs from the end of August through to early November with the majority falling through September. However, over the eighteen months of wet weather following the prolonged drought that ended in early 2020, mangrove seeds were washing up every month of the year. This required a massive effort to clear mangrove seedlings from all the sites in 2022. Thankfully the effort required in 2023 was back at a sustainable level.

Figure 3. Intrepid Landcarers cutting mangroves on Smith Island. (Photo T. Clarke)

Figure 4. Volunteers sweeping the marshes at Stockton Sandspit. (Photo T. Clarke)

Results to date. Removal of fringing mangroves and woody weeds from the roost area had an immediate positive effect. Most of the shorebirds quickly re-occupied Stockton Sandspit. This continues to be the case with Stockton Sandspit being one of the main daytime roosts used in the Hunter Estuary. Similar success has occurred at other sites but has not been quite as outstanding. These sites tend to be used by smaller aggregations of birds but are complementary to the Stockton Sandspit as different shorebird species prefer them. Some of the additional sites are frequently used as back-up roost sites when the preferred site is suffering unusually high levels of disturbance, often due to human activity.

Figure 5. Final sweeps over Milham Pond by Hunter Bird Observers Club volunteers in 2022. (Photo T. Clarke)

Figure 6. Mass drop of mangrove seeds happens every year at Stockton Sandspit and other places. Six months later the surviving seedlings are removed by volunteers. (Photo T. Clarke)

Lessons learned and future directions. Working on the inter-tidal areas has required that we develop an understanding of how the estuary system operates. In the early years lots of tide notes were collected for each site as well as shorebird movements. Utilising favourable tides gives better access and improves efficiency. Understanding certain shorebird behaviours also improves our efficiency. Quite often, a couple of forward scouts in the form of godwit or curlew will fly over a roost site on an inspection loop prior to the main rush of the various flocks. This is the signal for workers that it is time to vacate the site.

Many techniques and a variety of hand tools have been trialled with differing levels of success. Hand-pulling the seedlings has proven to be the most efficient. We have found that it is possible to manage the mangroves without the use of chemicals. Cutting stems lower than the next high tide results in the stumps being immersed and the tree dies. This also works for seedlings that are snapped-off. In situations where the substrate is firm enough, seedlings can be snapped off at ground level using a hoe. However, this method doesn’t work in soft mud as the plant bends away rather than breaking. Where seedling recruitment is dense, a battery-powered brush cutter has been utilised. This method was very useful during the year of continuous seeding.

While the initial work was motivated by a sense of obligation to intervene, the ongoing work provides positive feedback that maintains the energy and brings much satisfaction to the carers. This happens on every occasion that we witness the arrival of the shorebirds to the places that are restored each year, a positive joy. Maintenance of the various roost sites has become a wonderful opportunity to introduce people to shorebirds.

Stakeholders and funding bodies. At each stage of the project an initial effort of primary works was carried out by contractors and funded through various Government programs including the Australian Government’s Caring for Our Country, Envirofund and Threatened Species Recovery Fund.   The following have supported the works in some manner over the last twenty years; Twitchathon, Bird Interest Group Network (BIGNet), Birdlife Australia,  Conservation Volunteers Australia, the NSW Departments of Primary Industries and Fisheries, and Planning and Environment (and their predecessors), Hunter Bird Observers Club, Hunter Catchment Management Authority, Hunter Local Land Services, Hunter Regional Landcare Network, Kooragang Wetlands Rehabilitation Project, NSW National Parks & Wildlife Service, Newcastle Kayak Tours, Newcastle City Council, Newcastle Coal Infrastructure Group, NSW Government, Toolijooa, Trees In Newcastle, University of Newcastle.

The volunteer effort has been led by members of HBOC that make up the core team. Additional contributions have been made from other groups from time to time including: Better Earth Teams, Green Army, International Student Volunteers, TAFE students, Koora Gang, Intrepid Landcare, Worimi Green Team, Stockton Scouts, Raymond Terrace Scouts, Al Gazzali and Rigpa Buddists.

Contact information. For more information contact Tom Clarke thomas.clarke7@bigpond.com and project reports can be viewed on the HBOC website Rehabilitation Projects – Hunter Bird Observers Club (hboc.org.au).

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Posted in Assisted regeneration, Coastal & marine, Community involvement, Fauna & habitat, Integrating ecosystems & industries, Landscape pattern & design, Mangroves, Migratory shorebirds, Mudflats, New South Wales, Restoration & management theory, Saltmarsh, Techniques & methodology, Threatened species & communities, Urban ecosystems, Weed issues & solutions, Wetland

Rewilding lake edges at Sherwood Arboretum, Queensland

Posted on 8 July 2023 by | Comments Off on Rewilding lake edges at Sherwood Arboretum, Queensland

Carole Bristow

Figure 1. The site in 2014, 5 years prior to works, showing the lack of wetland fringing vegetation due to it being regularly brushcut. (Photo Friends of Sherwood Arboretum)

Sherwood Arboretum, 15 hectares in size, contains a collection of planted (specimen) Queensland native trees under the supervision of Brisbane Botanic Gardens. Located in the suburb of Sherwood in Brisbane, the Arboretum has the Brisbane River as its western boundary and there are three small watercourses running both into and out of two lakes, providing habitat for wildlife. Before the development of the Arboretum in 1925, the lakes were a single paperbark swamp with small patches of open water. An early city water main ran across the swamp roughly dividing it in two. In 1975 the water main was covered by rocks and soil to form a causeway/walking path, and the swamp was reshaped to form two open lakes containing three islands. Many species of birds use the lakes, the watercourses, and the Arboretum as a whole, gathering and dispersing according to season or changes in management.

Prior to the commencement of regeneration treatments the edges of the lake were relatively barren (Fig 1), kept in this condition by regular mowing and brushcutting which led to occasional collapses of the edges into the lake.  Close inspection found around 14 natives among the weeds being mowed and brushcut; so the idea came that perhaps the natives could be allowed to grow and protect the edge.  This would also form a natural plant community and potential faunal habitat. Twenty weed species were observed, including Signal Grass (Brachiaria decumbens), Green Panic (Megathyrsus maximus var. pubiglumis), Bahia Grass (Paspalum notatum), Slender Pigeon Grass (Setaria parviflora), Blue Couch (Digitaria didactyla), Blue Billy Goat Weed (Ageratum houstonianium), Creeping Indigo (Indigofera spicata).

Works undertaken. In 2019, agreement was reached to discontinue mowing to the edge and brushcutting, and to trial bush regeneration-style weed management along a manageable portion of the lake edge; that is, both sides of the causeway.  The work was carried out by two members of the Friends of Sherwood Arboretum bushcare group, a Habitat Brisbane bushcare group which is supported by Brisbane City Council.   The two volunteers worked on a weekly basis over 4 years, gradually removing weeds to release native plants.  The technique involved weed removal prior to weed seed shed while allowing natives to seed.  The objective was to reduce weed soil seed banks and recharge native soil seed banks over time.

Figure 2. The north-west corner of the causeway in 2021 showing high density natives, particularly Willow Primrose. (Photo Gordon King)

Results to date. As weed cover declined markedly, natives increasingly reappeared, dominating the site within two years.  At the peak of the site’s recovery, 34 native wetland herbaceous species had returned – many of these in high abundance in particular locations Figs 2-7).  These particularly included Tassle Sedge (Carex facsicularis), Emu Foot (Cullen tenax), Narrrow-leaved Indigo (Indigofera linifolia), Common Rush (Juncus usitatus), Willow Primrose (Ludwigia octovalvis), Slender Knotweed (Persicaria decipiens), Spotted Knotweed (Persicaria strigosa) and Poison Pratia (Lobelia concolor).

Water birds that also graze on land have been observed by the regeneration team to be increasingly using the lake edges – including Purple Swamphen (Porphyrio melanotus), Wood Duck (Chenonetta jubata) (Fig 6), Dusky Moorhen (Gallinula tenebrosa) and Intermediate Egret (Ardea intermedia).  The wetland plant insect life has also increased in the recovered areas.  As a result, the Chequered Swallowtail Butterfly (Papilio demoleus) (Fig. 7) is now seen among the Emu Foot, one of its host plants.

Figure 3. General view with White Eclipta (Eclipta prostrata), Slender Knotweed, Willow Primrose, Commelina (Commelina sp.) and Azolla (Azolla sp.) (Photo Gordon King)

Figure 4. Emu Foot. One of the natives tenaciously surviving even when there was a heavy weed presence. (Insets are of the characteristic five leaflets and the inflorescence.) (Photos Gordon King.)

Figure 5. Diversity of native species is high in some places – such as pictured here where Willow Primrose, Common Reed, White Eclipta, Binung (Christella dentata), Sprawling Bluebell (Wahlenbergia gracilis) and Emu Foot occur in close proximity. The waterlily is the introduced Mexican Waterlily (Nymphaea mexicana) and is controlled from time to time. (Photo Gordon King)

Figure 6. Wood Ducks foraging along the regenerating lake edges. (Photo Gordon King)

Figure 7. Insect life has increased including the Chequered Swallowtail butterfly for which Emu Foot is a host plant. (Photo Gordon King)

Changes over time. Composition has proven to be seasonally variable. At one point when the water had reduced to a very low level in the lake, muddy edges appeared, and Bacopa (Bacopa monniera.) emerged and flowered. A few days later there was rain and the water rose and covered the flowering plants – which are unlikely to return until muddy edges reappear. More recently, with heavy rains in February 2022, floodwaters covered all the banks to a depth of over 1m for several days.  Many species were severely affected, particularly Willow Primrose.  However a good recovery of all species is occurring.

A notable result of the work has been that the lake edges are no longer eroding and it is clear that valuable new habitat has been created.  These results provide more positive options for future management of the more extended lake edge should habitat restoration be undertaken in the future. It is an inspiring project to be involved in.

Acknowledgements: Brisbane Botanic Gardens and Brisbane City Council Habitat Brisbane program for agreeing to try this process. The Habitat Brisbane program also helped with occasional contractor support. Also thanks are extended to Gordon King, for his unflagging effort as fellow worker and for the use of his photographs.

Contact: Carole Bristow, bushcare leader, Friends of Sherwood Arboretum bristowc@bigpond.net.au

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Posted in Assisted regeneration, Bush regeneration, Community involvement, Ecosystem services, Erosion issues & solutions, Fauna & habitat, Freshwater aquatic, Queensland, Reserve management, Riparian & stream ecology, Techniques & methodology, Urban ecosystems, Weed issues & solutions, Wetland

Holistic regenerative management on a grazing farm, Allendale, Boorowa is leading to more complex native pastures and increased biodiversity

Posted on 29 April 2023 by | Comments Off on Holistic regenerative management on a grazing farm, Allendale, Boorowa is leading to more complex native pastures and increased biodiversity

David Marsh

Figure 1. David Marsh among native grasses that naturally regenerated at Allendale (Photo T. McDonald).

Introduction:  When we purchased the 814 ha ‘Allendale” property in the wheat-sheep belt of the Southwest Slopes of NSW in 1966, almost all of the plants that had evolved here over millennia had disappeared although Europeans had only been here for 142 years. All that remained of the woody components were some scattered Yellow Box (Eucalyptus melliodora), Blakeley’s Red Gum (E. blakelyi) , a few White Box (E. albens), a few Apple Box (E. bridgesiana), and very few Hickory Wattle (Acacia implexa). The ground layer, which normally includes most of the biodiversity in grassy woodlands had almost completely disappeared.

During first 18 years (of the 52 years) managing our farm we took a conventional approach to farming, having a largely economic relationship with the land and applying all the latest agronomy to lift yields. In 1989 we began a shift towards a process of ‘recovery grazing’ using Alan Savory’s  Holistic Resource Management approach. This was motivated not only by our values of wanting to leave the local landscape in healthy condition but also by the fact that the conventional mixed farming model was driving our farm  into incrementally increasing debt. We realized that we were attempting to run a fixed enterprises in a variable climate of recurring drought and that wasn’t working.  Training in holistic management with a certified educator in 1999 gave me the confidence to take the process more seriously, as did my enrollment in a Grad Dip. of Sustainable Agriculture followed by a Masters degree in Sustainable Agriculture.

The basis of recovery grazing is to avoid preferential and repeated overgrazing of desirable perennials by using rotational grazing in many small paddocks (to avoid repeatedly grazing recovering plants) rather than set grazing in a few paddocks. This allows longer recovery times for the desirable native perennial grasses and avoids creating conditions best suited to annuals of less value to livestock.  The ecological and economic results of our efforts have been outstandingly positive.

Works undertaken: Our first objective was to get costs under control. Surprisingly, for us this meant discontinuing cropping. Despite intermittent large profits from cropping our analysis showed that it was not profitable overall due to the number of dry years, wet harvests and frosts. We also started managing livestock differently. We created more land divisions using conventional or electrical fencing and, in our case, piping water to each paddock rather than radiating paddocks around the dams. (A trial of the latter showed it would cause too much erosion over time.) The troughs, energiser and solar panels are moved with the cattle, each move taking less than an hour.  Fencing and water cost us $85/ha at the time and was completed in 5 years, which compared favourably to spending $70K a year on fertilisers and pesticides during our cropping phase.  Instead of 12 mobs of cattle and 26 paddocks we now have 104 paddocks (and usually one mob of cattle), running them on an agistment basis that happens to suit us. Each paddock is only grazed for a total of about 10 days per year which gives time for not only existing pasture species to recover but for new species to recruit.

Most of our vegetation restoration approach relies on natural regeneration including both groundcovers and trees.  But we have planted quite a few scattered trees and have also sown some native grass seed – either hand broadcasting after collecting it from roadsides (or where it has recovered on the property) or after mechanized seeding of purchased batches from other farmers interested in the same process.  Cattle are also agents in seed dispersal as they spread it when grazing plants with ripe seed. A technique that we have used occasionally is to intentionally move the mob from a paddock with ripe seed (after they have had a big feed)  to a paddock that doesn’t have much of the species we wish to encourage. Effectively the cattle are harvesting and sowing the seed for us at no cost.

Figure 2. Increase in native grass presence at Allendale over time. (1999 -2020)

Results to date:

Woody vegetation. Tree cover on Allendale has increased from 3% cover in 1966, to over 20% in 2022 (through both tree planting and natural recruitment). Since 2010 – when it rained after a nine-year dry spell – the big remnant trees began to reproduce. The long recoveries from grazing allowed around 800 saplings (with temporary electric tape to protect them from being grazed for a few years), to survive and become trees. This is the first time any native trees have germinated and survived on Allendale in over 100 years.  Wattles (Acacia spp.) were originally direct seeded and are now recruiting.  This increase in woody vegetation and cycling provides the basis for a far more complex ecosystem on Allendale (with more insects, small reptiles, birds and a range of mammals) compared to recent previous decades.

Bird life. With these changes, a whole lot of other ecological shifts are also occurring at no cost. These days there are many thousands of quail (Coturnix sp.), finches (Neochmia spp.) and wrens (Malurus spp.) are present in increasing numbers. Dusky Wood Swallow (Artamus cyanopterus cyanopterus) and White-browed Wood Swallow (Artamus superciliosus ) come nearly every year and breed here; the Rufous Songlark (Cincloramphus mathewsi ), a ground nesting bird that we seldom saw previously, is now frequently observed. Various raptors are constantly here; the Black Shouldered Kite (Elanus axillaris), Nankeen Kestrel (Falco cenchroides), Wedge-tailed Eagle (Aquila audax), Brown Falcon (Falco berigora), Swamp Harrier (Circus approximans), Spotted Harrier (Circus assimilis) and Peregrine Falcon (Falco peregrinus) are frequent visitors. To date there have been 128 species of birds identified on the property, and we have observed informally that many of these species (and their abundance) have increased in recent years.

Grasses. Cibolabs analyses have shown that our ground cover levels have been at 100% for many years now and there have been particular increases in native grasses (Fig. 1).  We mapped the native grasses on the property in 1999 and found them present in only 1 ha out of 814 ha and confined to rocky outcrops that could not be ploughed and in a few fence corners. Repeat mapping in 2004/5 showed native grasses covered a larger area (~86ha) – with further increases mapped in 2010 (189ha) and 2020 (440ha) (Figs 2-5).  Indeed, representatives of the warm season perennials that evolved here can now be found in most if not all our paddocks even though too scattered to map.

The grass species include wallaby grasses (Rytidosperma spp.), Common Wheat Grass (Elymus scaber), spear and corkscrew grasses (Austrostipa spp.), Umbrella Grass (Chloris truncata), Kangaroo Grass, (Themeda triandra), Weeping Grass (Microlaena stipoides), Box Grass (Paspalidium distans), Arm Grass (Brachiaria milliformis), Queensland Blue Grass, (Dicanthium sericeum), Red Grass, (Bothriocloa macra), Cotton Panic (Digitaria brownii) and Wild Sorghum (Sorghum leiocladum). All these species have increased markedly in recent years, with the big stand-outs being Arm Grass, Box Grass, the wallaby grasses and Umbrella Grass (See Appendix 1).

While we believe the grasses would have gradually increased over time without sowing, we have accelerated the process by sowing some species in small quantities using a disc seeder in some sites, but mainly broadcasting seed by hand from a quad bike (Figs. 3 and 4 0a.nd Appendix 1).  Seeds were also dispersed by the cattle.

Figure 3. Locations of seed sowing treatments over time at Allendale.

Figure 4 Locations of seed sowing treatments over time at Allendale.

Figure 5. Native grass presence in all Allendale paddocks (with and without sowing) by 2020

Non-natives.  Achieving change has been more difficult in the paddocks where we had previously introduced exotic seed mixes including Cocksfoot (Dactylis glomerata) and Phalaris (Phalaris aquatica). These two perennial exotic grasses are highly dominant and can temporarily competitively exclude native grasses (even if the latter may still be present) –  particularly in wet seasons.  Experience suggests that this may  explain why native grass sowings in recent high rainfall years have not yet shown results (Figs 4-5).  These species are still valuable for grazing, however, as is Paspalum (Paspalum dilatatum) – which has increased – and Plantain/Ribwort (Plantago lanceolata) which is considered beneficial to the quality of the pasture.

In general, however, managing ground cover to reduce bare ground has helped managed disturbance-adapted invasive weeds such as Illyrian Thistle (Onopordum illyricum), Patterson’s Curse (Echium plantagineum), Capeweed (Arctotheca calendula) and Amsinckia (Amsinckia spp.); all of which now occur only occasionally. Importantly, we previously had an annual spraying program for some of the problematic annuals but we have not done that for 22 years;  managing ground cover to reduce bare ground goes a very long way to manage the populations of disturbance-adapted species. Any small patches of high-risk weeds (e.g. Rubus sp. and Rosa sp.) have proven manageable by mattocking out.

Lessons learned: Our goal is to live in a landscape increasing in biodiversity and to meet our economic goals. Over 30 years we were expending large amounts of money on contractors while rolling the dice against the weather, with little time for holidays.  We have found that we now usually have perennial native grasses dominating in summer and that this avoids the previous boom and bust cycle. The recovery grazing management (probably combined with reduced nutrient loads) has now resulted in more diverse native perennial pastures and avoids the cost of resowing. This allows time for habitat to develop to increase native fauna and allows us to produce time for recreation.

The benefits we have seen however, required a changed mindset.  It is quite hard for farmers to avoid intervening.  We had lots of weeds for many years because our previous management had pushed succession all over the farm back to an early state due to the creation of bare ground, even though we had sown perennials. A more mature succession took 3-5 years after ceasing sowing, weed control and overgrazing, so it did not occur overnight.  Importantly, all this required quite a philosophic conversion. Quite a lot of the farmers going down this track show a shift in attitude, characterized by patience and a greater willingness to take responsibility for land outcomes.  Such a changed mindset is not yet being entertained by the number of farmers needed to stop the slow but inexorable decline of biodiversity on farmland.   Yet more farmers are thinking about it now compared to in the last 20 years, which is an encouraging sign.

Acknowledgements: Thanks goes to my family (Mary Marsh, Skye Rush, Hugh Marsh and Alice Needham) and to my farming colleagues that have also been going on this journey (Charles Massy, Colin Seis, Martin Royds and Scott Hickman) .

Contact: David Marsh, Allendale, Boorowa NSW, Australia. Email: marsh.allendale1@gmail.com

Appendix 1. The main grass species, treatments and results at Allendale over approximately two decades.

Species Intervention Results
Wallaby grasses (Rytidosperma spp.) Very little seed has been scattered of one variety only Six varieties are now present and appeared within 3-5 years. All are spreading.
Box grass

(Paspalidum distans )

 Included in the total of  ~8×40 kg bags of seed purchased from another farmer, Colin Seis, over the years) and hand dribbled in rows about 20m apart from the quad bike.  Also included in the ‘Seis mix’ disc-seeded into paddocks totalling 150ha. In 1999 only found in one or two small patches but now it is every across the property
Umbrella Grass

(Chloris truncata)

 Included in the above-described ‘Seis mix’ hand dribbled and disc-seeded Was present in 1999 but now it is widespread as the seed heads are like umbrellas and tumble
Arm Grass  – Brachiaria milliformis Included in the above-described ‘Seis mix’ hand dribbled and disc-seeded Was absent when first came here.  Now it is widespread and increasing all the time.

 
Kangaroo grass – (Themeda   triandra) A total of half a wool pack from nearby roadside has been dispersed by hand from a quad bike over the ~15 years (split over ~four occasions). Was absent when first came here but was present on the roadside. It is not spreading rapidly but is starting to come back.

 
Corkscrew and tall Stipa

(Austrostipa spp.)

 

 Pre-existed and not collected. Some was present in uncropped areas. As a pioneer it can now be seasonally abundant.
Red grass (Bothriochloa macra) A little pre-existed was original present  but some is in the ‘Seis mix’ hand dribbled and disc-seeded Some was present in uncropped areas. It is now increasing although quite slowly.
Weeping grass (Microlaena stipoides) Some seed was included in grass culms harvested from a nearby property and ‘blown’ out onto some Allendale paddocks by Owen Whittaker. Some was present in uncropped areas.  It is gradually increasing.
Common Wheat Grass (Elymus scaber)

 

 No seed was sown but have collected from Allendale paddocks and distributed by hand a from quad bike. Some was present in 1999 but it is now spreading extensively. The species is relatively insignificant but has a place in a pasture.

 

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Posted in agricultural lands, Assisted regeneration, Cultural & socio-economic issues & solutions, Ecosystem services, Fauna & habitat, Grassland/grassy understorey, Integrating ecosystems & industries, New South Wales, Reintroduction, Restoration & management theory, Techniques & methodology, Weed issues & solutions

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Highly resilient response at a Cooma restoration site points to native plant adaptation to drought and short growing seasons

Posted on 6 October 2022 by | Comments Off on Highly resilient response at a Cooma restoration site points to native plant adaptation to drought and short growing seasons

Tein McDonald

Figure 1. One of the many ‘before and after’ photo pairs showing how, (a) at the start of the project in 2019, a near-monoculture of African Love Grass was persisting even during the drought – but (b) native regeneration boomed after two seasons of good rain and regular spot-spraying of the prolific and diverse weed that regenerated along with the natives.

Introduction. Assisted regeneration works have been undertaken over three seasons at a small (4ha) but uncleared privately owned bush block on the urban boundary of Cooma in the southern tablelands of NSW. Degradation at the start of the project in 2019 reflected past land uses. Flatter areas disturbed by historic light sheep grazing and vehicular tracks appeared in poor condition, with infestations of serious weed, particularly bird spread shrubs and pasture weeds. Drought-induced dieback occurred across the site, along with evidence of overgrazing by macropods and rabbits. Most of the site’s extensive (lichen and moss-covered) granite rocky knolls, however, remained undisturbed and in good condition.

Results of the works were expected to be gradual, given that the area’s annual average rainfall was around 538 mm and growing seasons short due to the southern tablelands’ relatively cold climate. While these lower expectations were reasonable, they did not factor in the above average rainfall of the 2021-21 season and, particularly, the very high and evenly distributed rainfall of the 2021-22 growing season.

Vegetation community. The main vegetation association on the site (and the Reserve) is Ribbon Gum (Eucalyptus viminalis)-E Black Cypress Pine (Callitris endlicheri) grassy woodland, with co-dominant trees including Candlebark (E. rubida), Apple Box (E. bridgesiana), Broad-leaved Peppermint (E. dives) and Mountain Gum (E. dalympleana). Sweet Bursaria (Bursaria spinosa), Red-stemmed Wattle (Acacia rubida) and Woolly Grevillea (Grevillea lanigera) are common in the mid-storey, along with six Fabaceae shrubs. Out of the 88 native vascular plant species, 63 are herbaceous (15 grass species and 48 forb species including 13 Asteraceae) species.

Weeds. At least 40 weed species occur on site, falling into two groupings – shrubs and groundcovers. The most prevalent shrubs were Orange Firethorn (Pyrocantha spp.) and Cotoneaster (Cotoneaster spp.) The most prevalent groundcovers were African Love Grass (Eragrostis curvula), Yellow Catsear (Hypochaeris radicata), Smooth Catsear (Hypochaeris glabra), St Johns Wort (Hypericum perforatum), Hare’s Foot Clover (Trifolium arvense), Proliferous pink (Petrorhagia nanteuilii) and Fleabane (Conyza sp.).

Works undertaken. Works have focused on the systematic and careful spot-spraying of individual weeds, rigorously following up to avoid the weed recharging soil seed banks. Cut brush was also laid down in a brickwork pattern along the contours to retain waterflow (where erosion was an issue) or deter macropods (where overgrazing was an issue, see https://youtu.be/4hmLFSL_kHQ ).

At the commencement of the works, ‘before’ photos were taken from eight pegged photopoints and at least 10 other informal ‘before’ shots across a wider range of subsites. Condition class mapping was undertaken using a 5-scale system adapted from the system used by the NSW National Trust since the 1980s.

Figure 3. (a) Before and (b) after treatment at the ‘Rabbit flat’ subsite. This area was highly drought affected and overgrazed by kangaroos and rabbits in 2019. Weed trimmings were laid on the site to reduce sheet erosion and grazing. Weeds were regularly controlled, particularly African Love Grass and Hare’s Foot Clover. Drought breaking rains triggered germination of mainly Golden Everlasting (Chrysocephalum apiculatum), New Holland Daisy (Vittadinea cuneata) and range of other natives. Very little African Love Grass and other weeds now persist at this site.

Weed treatments (totalling approx. 250 hours) were carried out over three growing seasons (Spring- Autumn) starting in December 2019 and extending till May 2022 (Table 1). By far the most hours (237) were directed to precision knapsack spot-spraying of groundcover weeds, with relatively few hours treating shrub weeds. The highest input was required in the third season, due to its exceptionally favourable rainfall (Fig. 2) when we needed to increase our inputs to treat all herbaceous weed across the whole site prior to their setting seed and recharging seed banks.

Table 1.  Hours involved in spot-spraying of groundcover weed for each of the three seasons.

Season 1  (2019-20) Season 2(2020-21) Season 3(2019-20)
77 56

Figure 2. Rainfall records at the site over three growing seasons from December 2019 to May 2022 (Blue bars is rainfall recorded at East St, Cooma; the red line the mean rainfall recorded at the Cooma Visitor’s Centre).

Results to date. While the site is far from fully recovered and works will be ongoing, results to date are encouraging. Figures 1 and 3 are three of many before and after photo pairs that compare the condition of all subsites prior to work with native plant recovery by January 2022 –24 months after the first drought-breaking rains. (Also see multiple photos at https://youtu.be/wjNviPl-MqY .) The condition classifications prior to works and at 3 seasons after works are shown in Figure 4.

In general most sites appear to have moved up in condition by at least one class; there is now substantially more area of medium to high condition after treatment compared to prior to treatment. However this result is still somewhat uncertain as the degree to which some of the Hare’s-foot Clover may have matured prior to spraying is unclear. The test of condition will be in Spring during the next above-average rainfall year.

Figure 4. Condition mapping (a) before and (b) after 3 seasons using a five-level condition classification system. The two maps show an increase in area of the green end of the spectrum (higher condition) and a reduction in area at the red end of the spectrum (lower condition). [The colour-coding and criteria are based on a four-level system used traditionally in the bush regeneration industry developed by the National Trust in the 1970s then modified during the 1990s by T. McDonald and subsequently resequenced to align with the 1-5 sequencing used in the 5-star system of the National Restoration Standards.]

Lessons learned and future directions.  The resilience level of this cold-climate, drought-affected plant community proved to be surprisingly high and growth relatively rapid after highly favourable rainfall. This may indeed be due to the species’ adaptation to periodic drought and short growing seasons.  Importantly (as elsewhere) such resilience also lends a capacity for natives to recover after periods of weed domination if that weed is removed.

It is logical to view the pattern of drought followed by highly favourable rainfall as somewhat similar to wildfire followed by highly favourable rainfall.  In such circumstances there is benefit in systematically treating as large an area as possible to (i) take advantage of the opportunities for rapid recovery of natives and (ii)  avoid massive and unusual recharge of weed seedbanks that could set a site’s condition back by many decades. While the landholders in this case did the work themselves and could increase or decrease work as required per season, cases relying on public funding would benefit from contingency funding being set aside for supporting additional restoration inputs in high rainfall seasons post-fire or post-drought.

Stakeholders.  The works were carried out by the block’s landholders Tein McDonald and Graeme Little.   Friends of Grassland helped with plant identification and encouragement and provided a small grant  to offset the costs of herbicide and equipment.

Contact:  Tein McDonald teinm@ozemail.com.au

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Posted in Assisted regeneration, Bush regeneration, Grassland/grassy understorey, New South Wales, semi-arid, Techniques & methodology, Weed issues & solutions

Post-fire assisted regeneration at Rutidosis Ridge, Scottsdale Reserve, Bredbo NSW

Posted on 2 May 2021 by | Comments Off on Post-fire assisted regeneration at Rutidosis Ridge, Scottsdale Reserve, Bredbo NSW

 

Figure 1. Undamaged grassy woodland reference site occurring at high elevation at Scottsdale (Photo: Brett Howland)

Introduction. Scottsdale Reserve is a 1,328-hectare private conservation reserve, near Bredbo NSW, owned and managed by Bush Heritage Australia. For over 100 years prior to purchase in 2006 the property was utilised for grazing and cropping. While most of the higher elevation areas of the property remained intact and offered the basis for improving landscape connectivity for wildlife, the agricultural land use had resulted in conversion of the flats and lower slopes of the property to largely exotic pasture species and accompanying weed.

This case study focuses on one approx 10 ha Apple Box (Eucalyptus bridgesiana) / Snow Gum, (Eucalyptus pauciflora) grassy woodland ridge within the property – named ‘Rutidosis Ridge’ because it is the location of a small population of the Endangered plant species Button Wrinklewort (Rutidosis leptorhynchoides). Set-grazing by sheep as well as some cropping had left the site nearly wholly dominated by the landscape-transforming exotic pasture grasses African Love Grass (Eragrostis curvula) and Serrated Tussock (Nasella tricotoma). Some scattered copses of eucalypts and some herbaceous natives remained, however, suggesting that the site might have some native regeneration potential, but the number and abundance of natives on the site appeared very low and the site was very dissimilar to a nearby healthy reference site (Fig. 1).

Works undertaken. Around a decade after land purchase and the discontinuation of grazing and cropping, Rutidosis Ridge was aerially sprayed during winter with flupropinate herbicide at a low dilution (1L / ha) known to be effective on some strains of African Love Grass and Serrated Tussock without killing native grasses and forbs. While the African Love Grass and Serrated Tussock had died by the following spring as a result of this soil-active herbicide, no substantial native regeneration was observed due to the persistence of the thick thatch of dead African Love Grass (Fig 2).

  • Figure 2.  Typical site showing sprayed African Love Grass thatch even many years after aerial spraying. (Photo T. McDonald )
  • Figure 3.  Intense wildfire that passed through Bredbo, NSW in early February. (Photo” New York Times)

An intense wildfire passed through the property on 2nd February 2020 (Fig. 3). This largely consumed the thatch, exposing stony topsoils and providing opportunities for regeneration of both natives and weeds that were stored in the soil seed bank.  Anticipating the need for post-fire spot-spray follow-up after the fire to avoid any native regeneration being overwhelmed by weed, Bush Heritage Australia (BHA) collaborated on a program of regular selective treatment of weed with the restoration organisation the Australian Association of Bush Regenerators (AABR). Personnel involved both contractors and volunteers skilled in recognising natives and weeds at seedling stage capable of spot-spraying with negligible off-target damage (Fig 4).  

Because the fire had removed African Love Grass thatch and cued germination of natives and weeds, the aim was to treat all weed prior to its seeding.  This allowed the managers to (a) take advantage of the fire’s flushing out the weed soil seed bank and avoid its further recharge and (b) retain maximum open spaces for further natives to emerge and colonise. 

During the year after the fire (March 2020-April 2021), the ~10ha site had been subjected to approx. 600 person hours of spot spraying, mainly undertaken by experienced bush regenerators. This commenced in March 2000 and continued at least fortnightly during the growing season.

Figure 4. Location of comprehensively spot-sprayed areas and target-weeded areas at Rutidosis Ridge. An opportunity exists to compare differences in richness and cover of natives and weed between the two treatments, ensuring comparisons are confined to within-comparable condition classes.

What we found by 1 year of treatments.  Post-fire observations in  March 2020 revealed Snow Gum resprouting from lignotubers and roots and Apple Box and Candlebark (Eucalyptus rubida) resprouting epicormically.  A wide suite of native grasses and forbs were starting to resprout or germinate alongside diverse herbaceous weeds. Within the first 12 months of regular spot-spraying, the cover and seed production of approx. 30 weed species was very substantially reduced.  Combined with fairly evenly distributed rainfall in the follow 12 months this reduction in weed allowed ongoing increases in native species cover and diversity per unit area, with seed production likely by most native species.  There was negligible off-target damage from the spray treatments. In December 2020 over 50 native herbaceous and sub-shrub species (including at least 11 Asteraceae, 9 Poaceae, 4 Fabaceae and 2 Liliaceae) were recorded within the work zones, with cover of natives very high in the higher condition zones, but plentiful bare ground remaining in the lower condition zones (Fig. 5).  

Figure 5.  Top:  Directly after wildfire showing black stubs of African Love Grass; Middle: Volunteers spot-spraying during the growing season, and Bottom: same site after 12 months but when native grasses were curing off after seeding. (Photos T. McDonald)

Predominant weed species included recovery African Love Grass, Viper’s Bugloss (Echium vulgare), St John’s Wort (Hypericum perforatum), Yellow Catsear (Hypochoeris radicata), Common Plantain (Plantago major), a range of thistles and around 20 other weed species.

Predominant natives included speargrasses (Austrostipa spp.), Redleg Grass (Bothriochloa macrantha), Kangaroo Grass (Themeda triandra), Native Panic (Panicum effusum), Common Raspwort (Gonocarpus teucrioides), Bindweed (Convolvulus erubescens), bluebells (Wahlenbergia spp.), Common Everlasting (Chrysocephalum apiculatum), fuzzweeds (Vitadennia spp.), Bear’s Ear (Cymbonotus lawsonianus), Creamy Candles (Stackhousia monogyna), Yellow Pimelea (Pimelea curviflora subsp. fusiformis) and Native St John’s Wort (Hypericum gramineum).  Species of higher conservation interest that regenerated included Blue Devil (Eryngium ovinum) and Threatened species that regenerated included Silky Swainson’s Pea (Swainsona sericea) and Button Wrinklewort. (Some of these species are pictured in Fig. 6).

Figure 6. Some of the forbs that flowered on Rutidosis Ridge during the growing season – including the Endangered Button Wrinklework (centre) and Vulnerable Silky Swainson’s Pea.(bottom left). (Photos various.)

Gradient of condition improving over time. As expected, the sites showed a gradient of condition (Fig. 7), with highest natural regeneration capacity retained in the tree clusters and stony crest, perhaps due to these less likely to be less favoured by sheep. (The tree clusters appear not to have been used as sheep camps). By March 2020, 1 year after work commenced, all sites were on a trajectory to move to the next higher condition class, assuming successful Winter 2021 aerial spray re-treatment of African Love Grass.  (Note that, while the pre-fire flupropinate treatment would normally have a residual effect for a few years and thus preventing germnation of this species, massive germination did occur of African Love Grass in many areas, which we speculate was either due to suitable post-fire germination conditions being delayed by the presence of dead grass thatch or to a possible denaturing of the chemical by the fire.)  

Figure 7. Condition classes in the Rutidosis Zones A-E revealed during the first few months of treatment. By the end of the growing season and after regular follow up spot-spraying it was clear that all zones comprehensively treated were improving in their native: weed cover ratio except for an increasing cover of African Love Grass, the treatment of which was deferred until a second aerial spray scheduled for winter 2021. (Map: T. McDonald)

Acknowledgements: This project would not have been possible without the help of BHA and AABR volunteers.

Contact: Tein McDonald and Phil Palmer, Scottsdale Tel: +61 (0) 447 860 613; Email: <teinm@ozemail.com.au and phil.palmer@bushheritage.org.au

 

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Posted in Assisted regeneration, Bush regeneration, Community involvement, Fire Ecology & Management, Grassland/grassy understorey, New South Wales, Restoration & management theory, Sclerophyll communities, Techniques & methodology, Threatened species & communities, Uncategorized, Weed issues & solutions

Crowdy Bay National Park, NSW – Assisted regeneration of a littoral rainforest patch post 2019-20 summer wildfire

Posted on 5 April 2021 by | Comments Off on Crowdy Bay National Park, NSW – Assisted regeneration of a littoral rainforest patch post 2019-20 summer wildfire

Figure 1. Volunteers at the initial working bee in the burnt littoral rainforest.

Introduction. Crowdy Bay National Park is located on the NSW Mid-north coast and comprises coastal landscapes, some of which have were sand mined prior to the area’s acquisition for conservation in the 1970s. Littoral rainforest remnant and regrowth patches occur within the Park and are listed at State level and as Endangered Ecological Community and at national level as a Threatened Ecological Community. The rainforest community type forms in the dune swales, protected by Coast Banksia (Banksia integrifolia) and is dominated over time by Tuckeroo ( Cupaniopsis anacardioides) and Beach Alectryon (Alectryon coriaceus), with other rainforest co-dominants and associated shrubs, vines and groundcovers.

For over four decades,  a regeneration program has been carried out in the park by volunteers working through the National Parks Association (NPA), Mid North Coast Branch. This short summary refers to the condition of one floristically diverse littoral rainforest patch at Kylie’s Beach, half of which was burnt in a spot-wildfire in late 2019 and in which weed managment works commenced 2 years prior to the wildfire due to pre-existing weed issues (Fig 1).

The wildfire and early recovery. The wildfire burnt all the banksias on the foredune crest that were providing wind protection for the littoral rainforest, as well as 1ha of the littoral rainforest. It left the ground layer beneath both areas largely bare. In the areas burnt, all trees appeared dead. With rainfall occurring soon after the fire, post-fire coppicing of rainforest trees and Banksia commenced; with germination of native seedlings occurring with the arrival of heavy rains in December 2020 -January 2021. By mid-autumn 2020 the northern foredune section was thickly covered with colonising Blady Grass (Imperata cylindrica) that provided cover for other successional natives (Fig 2) .

Weed recovery, however, was very rapid. As early as May 2020, the site was a sea of annuals, with abundant Lantana (Lantana camara), Coastal Morning Glory (Ipomoea cairica), Cape Gooseberry (Physalis peruviana), Crofton Weed (Ageratina adenophora) and scatterings of Cape Ivy (Senecio mikanioides) and Tobacco Bush (Solanum mauritianum). Volunteers were at a loss to see how the site could be helped to regenerate. Not having previously worked in a burnt rainforest, the first though was to take out all the weeds. Under the guidance of retired regenerator Tom Clarke from the Australian Association of Bush Regenerators (AABR) however, a different approach was taken.

Figure 2. Blady Grass has covered much of the floor.

Works undertaken. Commencing in May 2020 Sue Baker from NPA and Tom Clarke from AABR conducted monthly working bees to strategically remove weeds. The approach was to  regard the weeds as the new canopy cover and primary colonisers, providing invaluable shade and moisture retention for the regenerating rainforest species. It was agreed that the main initial objective was to see the re-establishment of a canopy, however low, to protect the ground moisture levels and any recovering herb layer. At this point any woody weeds were considered allies in that they were resprouting along with many native pioneer species. Treatment of woody weeds was selective and dependent upon direct competition with native plants. Instead, treatment of weed vines and creepers was targeted, with removal of Morning Glory and Cape Ivy a priority, at least to the edge of the burnt zone.

Subsequently, apart from preventing the spread of Cape Ivy and removing dense infestations of fruiting Cape Gooseberry, the method was to remove weeds only where they were competing with native seedlings with as much removal of their fruits and seeds as possible, followed by thinning out later where helpful. By January 2021, native ground cover had recovered sufficiently to remove the annuals, some of which were 2m high. Over time, the selective treatment of woody weeds has continued as more and more native regen appeared. By taking this approach we have left nature largely to do its own thing with minimal detrimental impact from weeding.

In addition, we have taken the view that the wildfire was not soley a negative; it has also provided an opportunity to address some of the long-standing weed issues in the broader area of Kylie’s Beach including that of Glory Lily (Gloriosa superba) and Golden Wreath Wattle (Acacia saligna) which the fire stimulated to germinate from the soil seed bank in their thousands.

As well as the weed management work, over a kilogram of native seed was broadcast in mid-summer 2020 in the hope it might improve recovery of the ecosystem.

Volunteer visits. After a site inspection tour on 14th May 2020 there have been at least 17 visits to Crowdy Bay National Park where regeneration works has been carried out, not only in the littoral rainforest, but also in the broader Kylie’s beach area. These occurred in May (1 visit), July (3 visits), August (4 visits involving 12 volunteers), September (2 visits), October (4 visits), November (1 visit) and lately in January 2021 (2 visits).

Figure 3. Tuckeroo coppicing from the burnt stump.

Figure 4. Lillypilly coppicing.

Results to date.  The site has demonstrated itself to have high levels of native resilience, having been in relatively healthy condition apart from per-existing weed infestations. High levels of rain in the 2020-21 summer has promoted extensive and vigorous growth. At February 2021, the forest floor was a carpet of native vegetation and some areas knee-high in dense native grasses. Less care in selecting woody weeds for treatment is now required.

Much of the regeneration is from germinating seeds but some has been from re-sprouting rootstocks, resprouting stems or coppicing from the bases of trees, including rainforest trees (Figs 3 and 4) although some large trees are dead  (See Table 1). With the assisted regeneration work (i.e. strategic weed removal post-fire) the site is quickly shifting from a predominantly weed-dominated post-fire succession to one dominated by native plants.

There is no evidence that the sown seed has yet contributed to the regeneration at this stage.  Native regeneration was occurring across the area prior to the date when germination of sown seed would be expected and it is now clear that additional seed was not required.

Plans for ongoing management.  The continued wet and humid conditions in summer 2021 have provided highly favorable conditions for regeneration. During 2021 the volunteers will try to keep up with the work at Kylie’s Beach through regular bush regeneration camp outs (as organised for many years, except 2020 which was cancelled due to COVID-19 restrictions). Work plans for the next camp-out have been scheduled to include the Kylie’s Beach littoral rainforest site and will include follow-up treatment of vines and Crofton Weed. Full recovery is likely to take years as the recovery process moves at its own pace.

Two major issues remain – dense ground and canopy cover of coastal morning glory in the area will need meticulous treatment. Also an entire drainage line on the steep, rocky cliff face behind the dune is densely infested with Crofton Weed that must be left in place to stabilize the slope until sufficient native cover takes hold. Volunteers were able to remove flowers from the Crofton Weed for a certain distance up the slope. Contractors will be needed in 2021 to deal with the upper slope.

Acknowledgements: We thank the organisation and leadership of NPA group.  The fact that this was already in place prior to the fire, was a key to the success of the work to date. This group has an outstanding history and connection with many sites in the Park over many years. The linking of AABR to the project provided additional support in project design and facilitating additional volunteer from the ABBR network for the post-fire restoration side of the program.

Contacts:  Tom Clarke AABR 0418411785 and Sue Baker (NPA MNC branch)

Table 1. Kylie’s Beach Littoral Rainforest Post Fire Restoration  – responses of native and exotic species (Exotics marked with an asterisk)

Scientific name Common name Response of the species at this site Notes
Grasses
Imperata cylindrica Blady Grass Resprouted Dominating burnt floor devoid of canopy
Oplismenus aemulus Basket Grass Resprouted and germinated Near edge of existing canopy
Ehrharta erecta* Panic Veldtgrass Germinated Hillside on open ground near crofton weed
Eriochloa procera Spring Grass Germinated Near edge of existing canopy
Scramblers and Climbers
Marsdenia flavescens Hairy Milk Vine Resprouted and germinated At edge of existing canopy
Senecio mikanioides* Cape Ivy Resprouted Remnants creeping through grasses, has been heavily targeted.
Ipomoea cairica* Mile-a-minute Resprouted and germinated Existing condition taking advantage, targeted for weeding
Desmodium sp. (varians?) Desmodium Germinated Carpeting over slope to dune swale
Glycine sp. (tabacina?) Love Creeper Germinated Carpeting over slope to dune swale
Sarcopetalum harveyanum Pearl Vine Resprouted and germinated Near edge of existing canopy.
Stephania japonica Snake Vine Resprouted and germinated Near edge of existing canopy or large remnant structures
Dioscorea transversa Native Yam Resprouted Near edge of existing canopy or large remnant structures
Passiflora edulis* Blue Passion Flower Resprouted and germinated Single isolated plant. Previously overlooked?
Rubus parvifolius Native Raspberry Resprouted and germinated Creeping through rank grasses
Cayratia clematidea Slender Grape Resprouted and germinated Creeping through rank grasses
Cissus antarctica Kangaroo Grape Resprouted Mostly at edge of existing canopy.
Tetrastigma nitens Three-leaved Water Vine Resprouted Near edge of existing canopy
Flagellaria indica Whip Vine Resprouted Isolated individuals searching for structure
Geitonoplesium cymosum Scrambling Lily Resprouted Creeping through rank grasses
Smilax australis Austral Sarspariila Resprouted Moving into grass floor plus climbing burnt structures.
Ground Covers and Herbs
Hydrocotle bonariensis* Pennywort Resprouted Associated with commelina in low swale
Commelina cyanea Scurvy Weed Resprouted Feature of low swale within open floor area; also underneath grasses.
Melanthera biflora Melanthera Resprouted Carpeting top of rise from dune swale
Tufted Plants
Crinum pedunculatum Swamp Lily Resprouted Seaward edge to dune swale
Dianella congesta Coastal Flax Lily
Lomandra longifolia Mat Rush Resprouted and germinated Isolated individuals, seedlings and survivors
Ficinia nodosa Knobby Club-sedge Resprouted Seaward side pushing up from dune swale below
Cyperus sp. (sanguinolentus?) Sedge Resprouted Associated with commelina etc in swale near False Bracken
Alocasia brisbanensis Cunjevoi Resprouted Scattered near edge of existing canopy or structures.
Ferns
Doodia aspera Rasp Fern Resprouted Mostly near edges of existing canopy
Pellaea falcata Sickle Fern Resprouted Mostly with grass at edge of existing canopy
Calochlaena dubia False Bracken Fern Resprouted Dense patches on floor adjacent to Blady Grass
Dicksonia antarctica Treefern Resprouted Unaffected individuals near edges
Shrubs
Acacia longifolia (var. sophorae?) Golden Wattle Germinated Seedling growth mostly seaward edge of floor.
Breynia oblongifolia Coffee Bush Germinated Isolated individuals from seedlings
Banksia integrifolia Coastal Banksia Resprouted and germinated Coppicing from burnt stumps plus seedlings
Physalis peruviana* Cape Gooseberry Rampant pioneer exotic targeted for weeding
Solanum nigrum* Blackberry Nightshade Germinated Rampant pioneer exotic targeted for weeding
Lantana camara* Lantana Resprouted Rampant pioneer exotic targeted for weeding
Poyscias elegans Celerywood Germinated Scattered seedlings
Trema tomentosa var. viridis Native Peach Germinated Pioneer from seedlings; competing well
Conyza sumatrensis* Tall Fleabane Germinated Rampant pioneer exotic targeted for weeding
Notelea venosa? Mock Olive Resprouted Coppicing from burnt stump.
Bidens Pilosa* Cobbler’s Pegs Germinated Rampant pioneer exotic targeted for weeding
Phytolacca octandra* Inkweed Germinated Isolated patches
Ageratina Adenophora* Crofton Weed Resprouted and germinated?? Isolated patches on floor plus large, dense infestation covering hillside soak
Chrysanthemoides monilifera* Bitou Bush Resprouted and germinated Isolated individual plants
Trees
Cupaniopsis anacardioides Tuckeroo Resprouted and germinated Coppicing from burnt stumps plus seedlings
Wilkiea huegeliana Wilkiea Resprouted Coppicing from burnt stumps
Homalanthus populifolius Bleeding Heart Germinated Pioneer from seedlings; competing well
Alectryon coriaceus Beach Tamarind Resprouted Coppicing from burnt stumps.
Solanum mauritianum* Tree Tobacco Germinated Pioneer exotic targeted for weeding
Ficus rubiginosa Port Jackson Fig Resprouted Coppicing from burnt stumps
Laurel type Coppicing from burnt stumps
Synoum glandulosum Scentless Rosewood Resprouted Coppicing from burnt stumps

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Posted in Assisted regeneration, Bush regeneration, Coastal & marine, Community involvement, Fire Ecology & Management, New South Wales, Rainforest, Restoration & management theory, Techniques & methodology, Weed issues & solutions

More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves – UPDATE of EMR feature

Posted on 30 September 2019 by | Comments Off on More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves – UPDATE of EMR feature

Ian Davidson

[Update of EMR feature – Davidson, Ian and Peter O’Shannassy (2017) More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves. Ecological Management & Restoration, 18:1, 4-14.  https://onlinelibrary.wiley.com/doi/10.1111/emr.12247]

Roger Harris with direct seeded shrubs –  Rand TSR. (Photo Ian Davidson)

Introduction.  As described in our 2017 EMR feature, the Enriching biodiversity in the NSW Riverina project was a five-year project funded by the Federal Government’s Carbon Farming initiative and managed by Murray Local Land Services (LLS). The project aimed to maintain the condition of the highest quality TSRs and improve the condition of 10% of all other TSRs, some of which had been receiving degrees of grazing management for many decades to optimize resilient native pastures (Refer to our earlier 2005, EMR feature). Given the NSW Riverina TSR network contains over 600 reserves, a sample was first selected for inspection to identify reserves with the potential for further active management. This led to the implementation of recommended land management and works on 109 reserves covering 13,558 ha and the subsequent monitoring of those reserves. Results indicated that, of these reserves, 70 had improved in vegetation condition by 2017. This project proved that large scale protection and improvement of TSR condition was possible using existing staff and provided valuable lessons that could be applied elsewhere across the state.

Table 1 Summary of key lessons learnt from the project and recommendations for effective TSR management

Human resources ·       Use existing knowledge where available

·       Maintain continuity of leadership
Assessment and

monitoring

 ·       Establish broadly applicable and consistent assessment and monitoring criteria

·       Use methods which are easily understood

·       Consider seasonal effects on the timing of surveys

·       Recommended actions should be appropriate for the site condition
Project Scale ·       Larger project areas and longer project timelines increase the rate of success

·       Regular monitoring avoids major problems
Revegetation ·       Seed banks are vital to achieving large scale revegetation

·       Multiple species should be used in direct seeding

·       Exotic grasses should be controlled prior to direct seeding

·       Native species can assist in spreading shrubs over time
Land Management ·       Controlling herbivores is critical during early growth stages

·       Grazing indicators/surrogates are useful

·       Stock type impacts grazing style

·       Cattle can graze areas with shrub seedling germination under certain conditions

·       Fencing and water points offer flexibility in managing stock for regeneration

·       Noisy Miners reduce small woodland bird numbers and they are difficult to control
Unplanned Impacts ·       Human intervention in unpredictable Natural events can lead to major changes in land management focus

Stuart Watson monitoring vegetation at Narrow Plains TSR. (Photo Ian Davidson)

Subsequent developments. Since the publication of our 2017 feature ‘More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves’ the following five key developments regarding nature conservation on TSRs in NSW have occurred.

  1. Developing and applying a simple field based consistent method for assessing and monitoring vegetation condition across the TSR network – A new rapid assessment and monitoring method was developed and trialed in this project for use by land managers with limited botanical and scientific skills and limited time. This field-based method known as Rapid Conservation Assessment Method (RAM) proved useful and has the potential for broader adoption across NSW. For detailed information refer to https://www.lls.nsw.gov.au/livestock/stock-routes/conservation-of-tsrs
  2. Categorizing the conservation status using an agreed method of TSRs across NSW – Using the RAM to complete assessments and collating all previously assessed TSR reports, LLS developed a consistent statewide map of the conservation status for the 534,000ha under their control (refer to https://www.lls.nsw.gov.au/livestock/stock-routes/conservation-of-tsr). This enabled LLS, the statewide land manager, to better understand the overall vegetation condition, extent and distribution of their TSR assets from a nature conservation perspective.
  3. Developing a Best environmental management practice (BeMP) Toolkit for TSRs to ensure good long-term conservation objectives – Key knowledge learnt from the Riverina project, LLS ranger’s knowledge and experience and existing literature influenced the development of the NSW Travelling Stock Reserves State Planning Framework 2016–21 (the Framework), which provides the framework for managing TSRs for conservation. A Best Environmental Management Practice (BeMP) toolkit was also prepared from this collation of knowledge to assist LLS deliver land management outcomes (including grazing, apiary, native seed collection, emergency response/refuge for livestock, threatened ecological communities and species, revegetation on TSRs, weed control, pest animal control, soil disturbance and drainage changes) consistent with the Framework. The BeMP is currently in draft form.
  4. Developing a statewide plan of management (PoM) for TSRs to ensure consistency across administrative boundaries – The NSW government is finalizing the details of a PoM which provides LLS staff, TSR stakeholders, investors, partners and customers with our shared vision and common mission. It sets out agreed strategies, approaches, principles and quality system to better manage the reserves. This PoM aims to improve social, economic, environmental and cultural outcomes while maintaining grazing as an important economic use and conservation tool. Importantly this plan establishes the need for shared responsibility and collaborative funding. For more information refer to https://www.lls.nsw.gov.au/__data/assets/pdf_file/0005/839930/NOV-TSR-PoM-MOedits-1.pdf
  5. Attracting significant investment to assist with protection and maintenance of TSR environmental values – LLS the managers of NSW TSRs receive no recurrent funding from government for the environmental management of the TSR estate and therefore have been dependent upon the proceeds from permits and leases e.g. grazing and annual grants e.g. weed and pest animal control to maintain the condition of TSRs. Now however, based on the PoM and guided by environmental management and works consistent with best environmental management practice, the LLS is negotiating with a government investor to fund agreed long term maintenance and enhancement of selected high and moderate conservation value TSRs.

Peter O’Shannassy with direct seeded shrubs on Snake Island TSR. (Photo Ian Davidson)

Lessons learned. Together, the five developments above show how the large-scale restoration project reported in 2017 has been further developed as a model for TSR protection and restoration across NSW, enabling buy-in by LLS to better manage these invaluable natural resource assets across NSW.

Acknowledgements. LLS staff Peter O’Shannassy steered most aspects of the project from its inception, whilst Stuart Watson and Roger Harris managed most of the on-ground management and works and lately Gary Rodda the Murray General Manager who has overseen the statewide development of the PoM. Lastly, I dedicate my TSR work to my great mate Rick Webster who was lost to us recently and with whom I shared a deep, long standing curiosity and love of these special areas.

Contact.  Ian Davidson (for technical matters) ian@regenerationsolutions.com.au  or  Peter O’Shannassy  (for land management and operational matters) peter.o’shannassy@lls.nsw.gov.au

 

 

 

 

 

 

Comments Off on More than just a Long Paddock: Fostering native vegetation recovery in Riverina Travelling Stock Routes and Reserves – UPDATE of EMR feature

Posted in agricultural lands, Assisted regeneration, Cultural & socio-economic issues & solutions, EMR 20th anniversary updates, Fauna & habitat, Grassland/grassy understorey, Integrating ecosystems & industries, New South Wales, Pest animal issues & solutions, Reserve management, Sclerophyll communities, Techniques & methodology, Weed issues & solutions

Ku-ring-gai Flying-fox Reserve Habitat Restoration Project at Gordon, 2000 – 2019 UPDATE of EMR feature

Posted on 26 September 2019 by | Comments Off on Ku-ring-gai Flying-fox Reserve Habitat Restoration Project at Gordon, 2000 – 2019 UPDATE of EMR feature

Nancy Pallin

[Update to EMR feature –  Pallin, Nancy (2001) Ku-ring-gai Flying-fox Reserve Habitat restoration project, 15 years on.  Ecological Management & Restoration 1:1, 10-20. https://onlinelibrary.wiley.com/doi/10.1046/j.1442-8903.2000.00003.x]

Key words:         bush regeneration, community engagement, wallaby browsing, heat events, climate change

Figure 1. Habitat restoration areas at Ku-ring-gai Flying-fox Reserve within the urban area of Gordon, showing areas treated during the various phases of the project. Post-2000 works included follow up in all zones, the new acquisition area, the pile burn site, the ecological hot burn site and sites where vines have been targeted. (Map provided by Ku-ring-gai Council.)

Introduction. The aim of this habitat restoration project remains to provide self-perpetuating indigenous roosting habitat for Grey-headed Flying-fox (Pteropus poliocephalus) located at Ku-ring-gai Flying-fox Reserve in Gordon, NSW Australia (Fig 1).  The secondary aim was to retain the diversity of fauna and flora within the Flying-fox Reserve managed by Ku-ring-gai Council. Prior to works, weed vines and the activity of flying-foxes in the trees had damaged the canopy trees while dense weed beneath prevented germination and growth of replacement trees.  Without intervention the forest was unable to recover.  Natural regeneration was assisted by works carried out by Bushcare volunteers and Council’s contract bush regeneration team.  The work involved weed removal, pile burns and planting of additional canopy trees including Sydney Bluegum (Eucalyptus saligna), which was expected to cope better with the increased nutrients brought in by flying-foxes.

Figure 2. The changing extent of the Grey-headed Flying-fox camp from the start of the project, including updates since 2000. (Data provided by KBCS and Ku-ring-gai Council)

Significant changes have occurred for flying-foxes and in the Reserve in the last 20 years.

In 2001 Grey-headed Flying-fox was added to the threatened species lists, of both NSW and Commonwealth legislation, in the Vulnerable category.  Monthly monitoring of the number of flying-foxes occupying the Reserve  has continued monthly since 1994 and, along with mapping of the extent of the camp, is recorded on Ku-ring-gai Council’s Geographical Information System. Quarterly population estimates contribute to the National Monitoring Program to estimate the population of Grey-headed Flying-fox.  In terms of results of the monitoring, the trend in the fly-out counts at Gordon shows a slight decline.  Since the extreme weather event in 2010, more camps have formed in the Sydney basin in response to declining food resources.

In 2007, prompted by Ku-ring-gai Bat Conservation Society (KBCS), the size of the Reserve was increased by 4.3 ha by NSW Government acquisition and transfer to Council of privately owned bushland. The Voluntary Conservation Agreement that had previously established over the whole reserve in 1998 was then extended to cover the new area.   These conservation measures have avoided new development projecting into the valley.

From 2009 Grey-headed Flying-fox again shifted their camp northwards into a narrow gully between houses (Fig 2).  This led to human-wildlife conflict over noise and smell especially during the mating season. Council responded by updating the Reserve Management Plan to increase focus on the needs of adjoining residents.  Council removed and trimmed some trees which were very close to houses. In 2018 the NSW Government, through Local Governments, provided grants for home retrofitting such as double glazing, to help residents live more comfortably near flying-fox camps.

Heat stress has caused flying-fox deaths in the Reserve on five days since 2002. Deaths (358) recorded in 2013, almost all were juveniles of that year.  KBCS installed a weather station (Davis Instruments Vantage Pro Plus, connected through a Davis Vantage Connect 3G system) and data loggers to provide continuous recording of temperature and humidity within the camp and along Stoney Creek.  The station updates every 15 minutes and gives accurate information on conditions actually being experienced in the camp by the flying-foxes. The data is publicly available http://sydneybats.org.au/ku-ring-gai-flying-fox-reserve/weather-in-the-reserve/Following advice on the location and area of flying-fox roosting habitat and refuge areas on days of extremely high temperatures (Fig 3.) by specialist biologist Dr Peggy Eby, Council adopted the Ku-ring-gai Flying-fox Reserve 10 Year Management and Roosting Habitat Plan in 2018.  Restoration efforts are now focused on improving habitat along the lower valley slopes to encourage flying-foxes to move away from residential property and to increase their resilience to heat events which are predicted to increase with climate change.

Figure 3. Map showing the general distribution of flying-foxes during heat events, as well as the location of exclosures. (Map provided by Ku-ring-gai Council)

Further works undertaken.  By 2000 native ground covers and shrubs were replacing the weeds that had been removed by the regeneration teams and Bushcare volunteers.  However, from 2004, browsing by the Swamp Wallaby (Wallabia bicolor) was preventing growth of young trees and shrubs.  Bushcare volunteers, supported by KBCS and Council responded by building tree cages made from plastic-mesh and wooden stakes. Reinforcing-steel rods replaced wooden stakes in 2008.   From 2011, the Bushcare volunteers experimented with building wallaby exclosures, to allow patches of shrubs and groundcovers to recover between trees (Figs 3 and 4).  Nineteen wallaby exclosures have been built. These range in size from 7m2 to 225m2 with a total area of 846m2.   Wire fencing panels (Mallee Mesh Sapling Guard 1200 x 1500mm) replaced plastic mesh in 2018.  Silt fence is used on the lower 0.5m to prevent reptiles being trapped and horizontally to deter Brush Turkey (‎Alectura lathami) from digging under the fence.

The wallaby exclosures have also provided an opportunity to improve moisture retention at ground level to help protect the Grey-headed Flying-fox during heat events.  While weed is controlled in the exclosures south of Stoney Creek, those north of the creek retain Trad and privets, consistent with the 10 Year Management and Roosting Habitat Plan.

Madeira Vine (Anredera cordifolia) remained a threat to canopy trees along Stoney Creek for some years after 2000, despite early treatments.  The contract bush regen team employed sInce 2010 targeted 21 Madiera Vine incursions.

A very hot ecological burn was undertaken in 2017 by Council in order to stimulate germination of soil stored seed and regenerate the Plant Community Type (PCT) – Smooth-barked Apple-Turpentine-Blackbutt tall open forest on enriched sandstone slopes and gullies of the Sydney region (PCT 1841).  This area was subsequently fenced. The contract bush regeneration team was also employed for this work to maintain and monitor the regeneration in the eco-burn area (720 hours per year for both the fire and Madiera Vine combined).

Figure 4. Exclusion fence construction method. Pictured are Bushcare volunteers, Jill Green and Pierre Vignal. (Photo N Pallin).

Figure 5. Natural regeneration in 2018 in (unburnt) exclosure S-6 (including germination of Turpentines). (Photo N. Pallin)

Further results to date. The original canopy trees in Phase 1 and Phase 2 (1987 -1997) areas have recovered and canopy gaps are now mostly closed. Circumference at breast height measurements were taken for seven planted Sydney Blue gum trees.  These ranged from 710 to 1410mm with estimated canopy spread from 2 to 6m.  While original Turpentine (Syncarpia glomulifera) had circumferences from 1070 and 2350mm with canopy spread estimated between 5and 8m, those planted or naturally germinated now have circumference measurements between 420 and 980mm with canopy spread estimated from 1.5 to 3m.  A Red Ash (Alphitonia excelsa) which naturally germinated after initial clearing of weeds now has a circumference of 1250mm with a canopy spread of 5m.  Also three Pigeonberry Ash (Elaeocarpus kirtonii) have circumference from 265 to 405mm with small canopies of 1 to 2m as they are under the canopies of large, old Turpentines.  As predicted by Robin Buchanan in 1985 few Blackbutt (Eucalyptus pilularis) juveniles survived while the original large old trees have recovered and the Sydney Bluegum trees have thrived.

In the Phase 3 (1998 – 2000) area south of Stoney Creek the planted Sydney Blue Gum now have circumferences measuring between 368 and 743 (n7) with canopy spread between 2 and 6 m.  in this area the original large trees have girths between 1125 and 1770mm (n7) whereas trees which either germinated naturally or were planted now range from 130 to 678mm (n12).  These measurement samples show that it takes many decades for trees to reach their full size and be able to support a flying-fox camp.

Wallaby exclosures constructed since 2013 south of Stoney Creek contain both planted and regenerated species.  Eight tree species, 11 midstorey species, 27 understorey species and eight vines have naturally regenerated.  Turpentines grew slowly, reaching 1.5m in 4 years.  Blackbutts thrived initially but have since died. In exclosures north of the creek,  weeds including Large-leaved Privet,  Ligustrum lucidum,  Small-leaved privet,  L. sinense,  Lantana, Lantana camara,  and Trad, Tradescantia fluminensis) have been allow to persist and develop to maximise ground moisture levels for flying-foxes during heat events. Outside the exclosures, as wallabies have grazed and browsed natives, the forest has gradually lost its lower structural layers, a difference very evident in Fig 6.

Figure 6. Visible difference in density and height of ground cover north and south of Stoney creek. (Photo P. Vignal)

Coachwood (Ceratopetalum apetalum) were densely planted in a 3 x 15m exclosure under the canopies of mature Coachwood next to Stoney Creek in 2015. In 4 years they have reached 1.5m.  In this moist site native groundcovers are developing a dense, moist ground cover.

Madiera Vine, the highest-threat weed, is now largely confined to degraded edges of the reserve, where strategic consolidation is being implemented with a view to total eradication.

In the hot burn area, which was both fenced and weeded, recruitment has been outstanding. One 20 x 20m quadrat recorded 58 native species regenerating where previously 16 main weed species and only 6 native species were present above ground. A total of 20 saplings and 43 seedlings of canopy species including Eucalyptus spp., Turpentine and Coachwood were recorded in this quadrat where the treatment involved weed removal, burning and fencing  (S. Brown, Ku-ring-gai Council, July 2019, unpublished data).  Unfortunately, however, the timing and location of the burn did not take into account its impact on the flying-fox camp and there was some damage to existing canopy trees. It will be many years before the canopy trees, which are regenerating, will be strong enough to support flying-foxes.

Monitoring from the weather station and data loggers has shown that close to Stoney Creek on a hot day it is typically 2-3° C cooler, and 5-10% higher in humidity, than in the current camp area (pers. comm. Tim Pearson). During heat events the flying-foxes move to this cooler and moister zone, increasing their chances of survival.

Fauna observed other than flying-foxes includes a pair of Wedge-tail Eagle ( Aquila audax plus their juvenile, a nesting Grey Goshawk (Accipiter novaehollandiae) and a Pacific Baza (Aviceda subcristata).  Powerful Owl (Ninox strenua) individuals continue to use the valley. The presence of raptors and owls indicate that the ecosystem processes appear to be functional. Despite the decline of the shrub layer outside fenced areas, the same range of small bird species (as seen prior to 2000) are still seen including migrants such as Rufous Fantail ( Rhipidura rufifrons) which prefers dense, shady vegetation. The first sighting of a Noisy Pitta (Pitta versicolor) was in 2014.  Long-nosed Bandicoot (Perameles nasuta) individuals appear and disappear, while Swamp Wallaby remains plentiful.

Lessons learned and future directions. Climate change is an increasing threat to Pteropus species. On the advice of Dr Eby, Flying-fox Consultant, Council, KBCS and Bushcare Volunteers agreed to retain all vegetation including weeds such as Large-leaved Privet and Small-leaved Privet, patches of the shrub Ochna (Ochna serrulata) and Trad as a moist ground cover in the camp area and areas used by the flying-foxes during heat events.

Building cheap, lightweight fencing can be effective against wallaby impacts, provided it is regularly inspected and repaired after damage caused by falling branches. This style of fencing has the additional advantage of being removable and reusable.  It has been proposed that, to provide understory vegetation to fuel future burns in parts of the reserve away from the flying-fox camp, further such temporary fencing could be installed.

Ku-ring-gai Council has commenced a  program to install permanent monitoring points to annually record changes in the vegetation, consistent with the state-based  Biodiversity Assessment Method.

Stakeholders and Funding bodies. Members of KBCS make donations, volunteer for monthly flyout counts, Bushcare and present educational events with live flying-foxes. KBCS hosts the website www.sydneybats.org.au. Ku-ring-gai Council which is responsible for the Reserve has been active in improving management to benefit both residents and flying-foxes.  Ku-ring-gai Environmental Levy Grants to KBCS have contributed substantially to purchase of fencing materials and the weather station. http://www.kmc.nsw.gov.au/About_Ku-ring-gai/Land_and_surrounds/Local_wildlife/Native_species_profiles/Grey-headed_flying-fox

Thank you to Jacob Sife and Chelsea Hankin at Ku-ring-gai Council for preparing the maps and to volunteer Pierre Vignal for assistance with tree measurements, downloading data loggers and a photo.  Researcher,  Tim Pearson installed the weather station.

Contact information. Nancy Pallin, Management Committee member, Ku-ring-gai Bat Conservation Society Inc.  PO Box 607, Gordon 2072  Tel 61 418748109. Email:  pallinnancy@gmail.com

Comments Off on Ku-ring-gai Flying-fox Reserve Habitat Restoration Project at Gordon, 2000 – 2019 UPDATE of EMR feature

Posted in Assisted regeneration, Bush regeneration, climate change, Community involvement, Cultural & socio-economic issues & solutions, Ecosystem services, EMR 20th anniversary updates, Fauna & habitat, Fire Ecology & Management, History, Monitoring, New South Wales, Planning, monitoring & assessment, Reserve management, Restoration & management theory, Sclerophyll communities, Techniques & methodology, Threatened species & communities, Urban ecosystems, Weed issues & solutions