Category Archives: Restoration & management theory

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

The Role of Swamps in Drought: Popes Glen Creek, Blackheath

Posted on 4 October 2020 by | Comments Off on The Role of Swamps in Drought: Popes Glen Creek, Blackheath

Alan Lane

Introduction

The important role of swamps in water storage and as regulators of stream flow has been well documented (10.1016/j.geomorph.2018.03.004). Previous EMR project summary reports on Popes Glen Creek, Blackheath, have described the establishment of a swamp on the former highly degraded and weed-infested silt plug at the headwaters of the creek.  (See links at end of this summary.)  That 18-year long project has been documented in “The Full Story”, https://dl.bookfunnel.com/ebgais2pxn and an 8-minute summary video can be viewed at https://www.youtube.com/watch?v=610sas330EQ

The recent severe drought in New South Wales provided the opportunity to monitor the water table in this swamp in the absence of rain and compare the impact on the swamp vegetation with that on more elevated and drier slopes nearby.

How we measured the water table. Six piezometers were installed at the start of this rehabilitation project, located about 50 m apart and midway between the edges of the long, rectangular silt plug. These went down to the bedrock, at depths of between 113 and 152 cm and were used to monitor water table depth and also for sampling water quality and stygofauna.

What we found. During periods of normal or above average rainfall (e.g. September 2019), the water table at each of these bore holes was typically at the depth below soil surface shown in Table 1.

Levels fell almost to bedrock during the drought (Oct 2019 – Dec 2019), before recovering after rains in January and February 2020 (Tables 1, 2). 

Table 1. Water table depths during normal and below-average rainfall periods.

Bore hole number
Depth below surface (cm) 1 2 3 4 5 6
Normal rainfall period (Sept 2019) 31 2 7 11 23 9
After drought period (Dec 2019) 103 106 121 103 – 123
After recovering rainfall (Feb 2020) 29 0 12 21 – 13

Table 2.  Rainfall, October 2019 – February 2020.

Month Rainfall (mm)1 5-year average (mm)2 % of average
September 2019 81.4 53.6 151.6
October 2019 23.8 76.7 31.0
November 2019 26.4 82.2 32.1
December 2019 0.4 69.5 0.6
January 2020 99.2 127.9 77.6
February 2020 560.4 183.6 305
  1. From Bureau of Meteorology, Mount Boyce, NSW
  2. From willyweather.com.au, Mount Boyce, NSW

During this period of extreme drought, the vegetation on the slopes above the Popes Glen swamp manifested extreme water stress in a way never before seen (Figs. 1, 2). Many of these extensive expanses of Coral Fern (Glycaenia dicarpa), stands of Fishbone Water Fern (Blechnum nudum) and individual Black Tree Fern (Cyathea australis) plants have not recovered and now appear unlikely to do so.

Figure 1. Expanses of severely water-stressed Glycaenia dicarpa on slopes above the Popes Glen swamp.

Figure 2. Many of the Blechnum nudum and Cyathea australis on slopes above the swamp have failed to recover.

In marked contrast, the vegetation in the swamp area (Fen Sedge (Carex gaudichaudiana), Tassel Sedge (Carex fascicularis), Tall Spikerush (Eleocharis sphacelata) and Juncus sp.) remained lush and vigorous (Fig. 3), suggesting it was sustained by the supply of water retained in the substrate.

This supply was progressively depleted during the drought and the water table had fallen almost to bedrock before the rains in January (Tables 1, 2).

Figure 3. Vegetation in the Popes Glen swamp remained lush throughout the drought.

Implications. It seems inevitable that this water supply would have been completely exhausted had the 2019-2020 drought lasted longer. Temperate Highland Peat Swamps on Sandstone (THPSS), including the Popes Glen swamp, appear threatened by the even more prolonged droughts anticipated as climate disruptions due to global heating become more marked.

Acknowledgements. This work was supported by Blue Mountains City Council and funding from the Environmental Trust of NSW.

Contact. Alan Lane alanlane388@gmail.com

See also EMR Project Summaries:

 

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Posted in Bush regeneration, climate change, Community involvement, New South Wales, Restoration & management theory, Wetland

The rise of invasive ant eradications since the success of the Kakadu project  – UPDATE of EMR feature

Posted on 3 October 2019 by | Comments Off on The rise of invasive ant eradications since the success of the Kakadu project  – UPDATE of EMR feature

Benjamin D Hoffmann

[Update of EMR feature – Hoffmann,  Benjamin D and Simon O’Connor (2004) Eradication of two exotic ants from Kakadu National Park. Ecological Management & Restoration, 5:2, 98-105. https://onlinelibrary.wiley.com/doi/10.1111/j.1442-8903.2004.00182.x]

Key words. pest species management, invasive species, biosecurity

Figure 1. Kakadu staff in 2001 spreading formicide over a super-colony of African Big-headed Ant. This involved a team of people, aligned in a row, walking from one edge of the infested area to the other in parallel paths. (Photo courtesy of Simon O’Connor.)

Introduction. Invasive species management, especially eradications, has been at the forefront of biodiversity conservation gains over the past two decades. For example, over 1,200 invasive vertebrate eradications have been achieved on over 800 islands worldwide and the conservation benefits of such actions have been overwhelmingly positive and often dramatic. Efforts against invasive ants have also been particularly notable over the past two decades, with ants now being the second-most eradicated taxa globally having been eradicated from more than 150 locations, with the largest eradication covering 8300 ha. Two decades ago there were only 12 confirmed ant eradications using modern baits with a combined area totalling a mere 12 ha.

As reported in our original EMR feature, the last treatments against two invasive ants in Kakadu National Park, northern Australia: The African Big-headed Ant (Pheidole megacephala) and the Tropical Fire Ant, (Solenopsis geminata) were conducted in 2003; and the ants were declared eradicated two years later (Hoffmann & O’Connor 2004). At the time this was a globally significant eradication, and the positive outcome was a partial catalyst for the creation of many other relatively small exotic ant eradication attempts around Australia, including against Tropical Fire Ant on Melville island, and African Big-headed Ant on Lord Howe Island. Incidentally, the work coincided with the approximate timeframe of when two other highly invasive ant species were first detected in Australia: Red Imported Fire Ant (RIFA) (Solenopsis invicta), and Electric Ant (Wasmannia auropunctata), prompting the initiation of two massive national cost-shared eradication programs. One of these, the RIFA program, has become Australia’s second-most expensive eradication program at AUD $428 million as of at July 2019. Together, all of these actions put ants high on Australia’s biosecurity and environmental management radars, prompting the development of Australia’s Tramp Ant Threat Abatement Plan and yet even more eradication programs.

Figure 2. Ant bait being dispersed aerially by helicopter using an underslung spreader and side-mounted dispersers. (Photos Ben Hoffmann)

Further advancements in ant eradication programs.  As Australia’s eradication programs became more numerous and larger, it became apparent very quickly that the methodologies and technologies available were insufficient to achieve success in the increasingly challenging conditions being encountered. In response, over the next two decades, there has been an impressive range of advancements that significantly improved our capacity to manage and eradicate invasive ant incursions.

The biggest issue was that work needed to be conducted over such large or inaccessible areas that ground-based work (Fig 1) was not feasible. So, treatments quickly became aerial, using multiple helicopter-based delivery platforms (e.g. underslung buckets and side-mounted hoppers, Fig 2). Even so, there have been locations that are too remote, too small, or too difficult (ie cliffs) to treat using a helicopter. To meet this challenge, in just the last five years treatments have been conducted for the first time using drones, and there is a great focus now to improve the technology so that it becomes more cost effective and more autonomous (Fig 3). This is occurring at such a pace that just a few years ago drones could only operate for a few hours at most on battery power, and only carry a few kilograms. This year we will be using a drone with unlimited flying capacity (petrol driven) that can lift 70 kg per load.

Figure 3. The Fazer with side-mounted bait carriers that can lift up to 40kg of payload. This is soon to be superseded by a drone that can lift a 70k g payload. (Photo Ben Hoffmann)

Assessments for the presence of ants, either before or after treatments, was originally very time consuming, involving teams of people walking ground very slowly and often utilising thousands of attractive lures (Fig 4). At most, only small ant populations (about less than 20 ha) within good working environments (ie open landscapes) could be assessed using teams of people, and it took large amounts of time. It was found very quickly that detector dogs could be trained on the scent of each ant species, and a single dog could cover more than five times the area of a team of people in a single day with greater efficacy (Fig 5). There are now more than 20 detector dogs operating in Australia and New Zealand that have been trained on the scent of four ant species. But even a team of dogs cannot fully cover entire areas at the landscape-scale, such as is the case for the RIFA program, especially in areas with long grass or rugged terrain. One of the saving technologies for the RIFA program has been the development of a multi-spectral sensor and associated algorithms that can identify RIFA nests from imagery captured by remote sensing (Fig 6). This allows program staff to assess just a few identified point locations in a landscape rather than the entirety of landscapes, to determine RIFA presence or absence. The next envisaged step is the development of biosensors that can detect the odours of target ant species, just like detector dogs, and with time these will become small enough to be transported by small drones throughout landscapes to detect ants.

Figure 4. An area covered with hundreds of flags marking spoonfulls of catfood being used as lures to attract African big-headed ant to assess eradication success or failure. (Photo Ben Hoffmann)

Figure 5. An ant detector dog searching for the presence of Red imported fire ant. (Photo courtesy of The State of Queensland (Department of Agriculture and Fisheries 2010–2019))

Australia was caught particularly unprepared two decades ago when the two new exotic ant species were detected for the first time because there were no baits registered for their management in Australia, so legally there were no treatment products that could be used. Even with the implementation of Emergency Use Permits for some unregistered products, as well as the use of the few products that were available for other species, it was often found that individual products could not be used in particular circumstances, especially around water, within crops and on organic farms. Additionally, available baits often did not have high efficacy. With time many baits (comprised of combinations of an attractive food laced with an active constituent) have been formulated and tested providing a greater array of baits that can be used on any new incursion and in numerous settings. The most recent has been the development of hydrogel baits that essentially deliver a liquid product in a solid form.

Figure 6 a and b. Multi-spectral camera flown underneath a helicopter to detect Red imported fire ant nests. (Photos courtesy of The State of Queensland (Department of Agriculture and Fisheries) 2010–2019)

Among the numerous advances described already, possibly the greatest development is on the threshold of becoming a reality, in the form of genomic solutions for individual species. RNA interference, and gene-drive technology are rapidly being developed for a suite of economically important species, and ants are among the taxa that are highest on the priority list as targets for this research. At best, these genomic advances promise to provide species-specific solutions, thereby alleviating the current non-target issues of using toxicants.

Conclusion. Our ability to eradicate ants has improved dramatically over the past two decades, with technologies and methodologies available now that were as yet not thought of back when our work was conducted in Kakadu National Park. New programs are constantly arising, and forging ahead in increasingly challenging situations, and a great deal of effort is placed in information-sharing among programs. Simultaneously there is a sustained focus to improve biosecurity at Australia’s borders, as well as throughout our region to help prevent the need for eradications in the first place.

Contact. Ben Hoffmann, Principal Research Scientist, CSIRO Health & Biosecurity (PMB 44 Winnellie NT 0822 Australia; Tel: +61 8 89448432; Email: Ben.Hoffmann@csiro.au).

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Posted in EMR 20th anniversary updates, Fauna & habitat, Indigenous land & sea management, Monitoring, Northern Territory, Pest animal issues & solutions, Pest species, Restoration & management theory, Techniques & methodology

Butterfly population persists 10 years after emergency habitat restoration and translocation – UPDATE to EMR feature

Posted on 30 September 2019 by | Comments Off on Butterfly population persists 10 years after emergency habitat restoration and translocation – UPDATE to EMR feature

[Update to 2008 EMR feature  –  Raymond Mjadwesch and Simon Nally (2008) Emergency relocation of a Purple Copper Butterfly colony during roadworks: Successes and lessons learned. Ecological Management & Restoration,  9:2, 100-109.   https://doi.org/10.1111/j.1442-8903.2008.00400.x]

By Simon Nally and Raymond Mjadwesch

Fig 1.  The endangered Purple Copper Butterfly (Paralucia spinifera) (Photo Raymond Mjadwesch)

Key words:  Paralucia spinifera, Purple Copper Butterfly, reintroduction, invertebrate, threatened species.

Introduction: As reported in the original EMR feature, the unintended destruction of the habitat of a population of the endangered Purple Copper Butterfly (Paralucia spinifera, Fig 1) north of Lithgow, Australia in 2004, precipitated a bold, innovative, and rapid emergency program of habitat restoration and butterfly larvae translocation.

A stand of the butterfly’s larval host plants, Blackthorn (Bursaria spinosa subsp. lasiophylla), had been largely destroyed to enable road construction (Fig 2a). The butterflies had commenced emerging from their nearly nine-month-long pupation in the attendant ant’s (Anonychomyrma itinerans) underground nests to find an absence of host plants.

Construction work ceased immediately, and supplementary Blackthorn plants were planted throughout the area of predicted butterfly emergence. The Blackthorn were planted in their pots, to allow for later removal and replanting in the area where the habitat was being restored.  The Blackthorn were sugar-baited to attract the attendant ant as the ant was assumed to affect the male butterfly’s selection of home ranges, and ultimately, egg-laying on these larval host plants. Concurrently with the provision of Blackthorn for egg-laying, an adjoining degraded area of potential habitat was treated for infestations of woody weeds and growth of emergent Eucalyptus trees that excluded Blackthorn or blocked sunlight, precluding its suitability for occupation by the species.  Once weeds were controlled, Blackthorn was established in this area using tube-stock planting.

Attendant ants were enticed to all the Blackthorn introduced to the site, male butterflies established territories and were successful at attracting females with whom to mate, and these females laid eggs on the Blackthorn. The project partners were relieved at these initial results! However, as much of the site was to be permanently destroyed due to road construction, this temporarily reprieved population had to be translocated.

Over 12 nights, 1,260 of the facultatively nocturnal larvae were collected (along with any associated attendant ants) as they emerged to feed on Blackthorn leaves and translocated to the newly created habitat established on an adjacent restoration area (Fig 2b). Each translocated larva was monitored until it was attended by ants (again attracted to the recipient habitat using a sugar bait). Further monitoring continued to confirm continued growth of larvae until pupation was assumed to occur.

The duration of the emergency habitat restoration and translocation activities from first discovery of the habitat destruction to the assumed pupation of the translocated larvae in the newly established habitat (Fig 3) was less than five months.

After the autumn and winter pupation period, the project partners were delighted to find butterflies emerging, mating, and laying eggs on the remaining restored habitat, one year after the initial habitat destruction was first detected. Monitoring of larval numbers during 2005-2008, which involved systematic nocturnal inspection of all Blackthorn plants at the site, indicated that the population was secure and had grown after an initial reduction in calculated numbers in the first year after translocation.

Figure 2a. 2004 – The site as found showing the extent of habitat destruction (when the butterfly and habitat loss was initially detected). (Photo Raymond Mjadwesch)

Figure 2b. 2005 – Larvae from yellow-delineated area were translocated (after temporary introduction) into the blue-delineated area and bushland further right. (Photo Raymond Mjadwesch)

Monitoring update: In 2013 and 2015 monitoring reverted to an area search method, counting flying butterflies – a technique routinely used to indicate butterfly distribution / areas of activity at each of the other known populations. In 2015, ten years after the emergency translocation and habitat restoration, 48 butterflies were observed in the restored habitat, the second highest number recorded for this site.

Note that the results of monitoring counts can vary with date of survey relative to the flying period, time of day, and weather conditions on the day, and represent an indicator of presence and activity rather than a measure of absolute abundance. During some years multiple monitoring events occurred; in 2013 and 2015 there was only a single monitoring count.

There have been no further nocturnal larvae counts since the culmination of the project.

A 2019 site assessment identified the need for further woody weed maintenance works (which has been ongoing in the interim, funded by the LLS) to avoid potential degradation of the habitat quality due to competition with and shading of the host plant, Blackthorn.  Longer term maintenance of this site may require active management to ensure persistence of Blackthorn either through burning or mechanical damage to Blackthorn to promote re-sprouting from the rootstock and juvenile leaf production. Juvenile leaves lack the hairy indumentum present on the lower surfaces of intermediate and adult Blackthorn leaves, and have been observed to be preferentially skeletonized by early-instar larvae.

The 2019 site inspection also revealed that powerline easement works had resulted in weedicide spraying of eucalypt (Eucalyptus ssp.) saplings throughout the restored habitat, with Blackthorn plants and other native plant species affected.

Figure 3a – the site in 2005, after restoration works were complete, showing the initial flush of pioneer species after soil disturbance and restoration. (Photo Raymond Mjadwesch)

Figure 3b – the site in 2019 showing the final shrubby understory of sedges and shrubs (including scattered Blackthorn) typical of the locally native open forest community. (Photo Raymond Mjadwesch)

Lessons learned and future directions: Several factors contributed to the success of the habitat restoration and translocation program, some of which were of notable serendipity. It was extremely fortunate that the species was detected within the affected area (after the initial survey of the site had failed to detect habitat for the species); that Blackthorn tube-stock (upon which the restoration relied) was available; that an area considered likely to support Purple Copper Butterfly suitable for rehabilitation lay adjacent to the affected area; and that the timing of the damage in the annual lifecycle of the species allowed the partners to work with the opportunity to establish larval food plants  when it was required.

However, we believe that it was human factors that fundamentally combined to create the environment for success:

  • the commitment of the NSW Roads and Maritime Services (then the RTA) to immediately and fully support restoration works to ameliorate the damage and maximize the chances of the population surviving in the long term, including changing the design of the works to reduce the extent of permanent damage, and the funding of the restoration, translocation, and monitoring activities.
  • the project partners, including the authors, the RTA, NSW National Parks and Wildlife Service, Australian Trust for Conservation Volunteers, and Lithgow LandCare unified in collaboration, ceasing other activities to direct all necessary effort to maximize chances of success.
  • the quick, resourceful and bold action to trial and implement innovative techniques that were risky and speculative, such as luring attendant ants to planted Blackthorn using sugar, trial translocating attendant ants, and translocating larvae.
  • that there had been sufficient field observations to  predict the likely behavior of butterflies and larvae and to predict the likely response of the species’ habitat to management intervention.

We encourage restoration practitioners to immerse themselves in the environments they intend to manipulate, and ponder on the behavior, function, and interactions between each element of the ecosystem before them. When choosing to act – to intervene – to manipulate, do so sensitively to what you both know and feel that you have learned in the field, and act decisively, quickly, and boldly. Most importantly, corral a team of partners who believe in the endeavor and who fully commit their support to each other for a common restoration objective.

Endnote: In September 2019, an unplanned fire burnt much of the site. Given the monitoring data available for this site, further monitoring to study the effect of fire on the species and its habitat is being considered.

 Stakeholders and Funding bodies:   NSW Roads and Traffic Authority (now NSW Roads and Maritime), NSW National Parks and Wildlife Service (now NSW Office of Environment and Heritage), Australian Trust for Conservation Volunteers, Lithgow LandCare, Australian Government Department of Environment and Energy

Contact information: Simon Nally, 8 Gurney Place PAGE ACT, Australia, Tel: +61 407870234, Email: suseandsimon@bigpond.com. Ray Mjadwesch, Mjadwesch Environmental Service and Support, 26 Keppel Street, Bathurst, NSW 2795 Australia, Tel: +61 423949789, Email:  ray@mjadweschenvironmental.com.au

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Posted in Assisted regeneration, EMR 20th anniversary updates, Fauna & habitat, faunal reintroduction, Integrating ecosystems & industries, New South Wales, Restoration & management theory, Sclerophyll communities, Techniques & methodology, Threatened species & communities

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

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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

Is revegetation in the Sheep Pen Creek area, Victoria, improving Grey-crowned Babbler habitat? – UPDATE of EMR feature

Posted on 24 September 2019 by | Comments Off on Is revegetation in the Sheep Pen Creek area, Victoria, improving Grey-crowned Babbler habitat? – UPDATE of EMR feature

Doug Robinson

[Update of EMR feature  – Robinson, Doug (2006) Is revegetation in the Sheep Pen Creek area, Victoria, improving Grey‐crowned Babbler habitat?  Ecological Management & Restoration, 7:2, 93-104.  https://doi.org/10.1111/j.1442-8903.2006.00263.x]

Key words: (<5 words): Monitoring, restoration, population ecology, woodland conservation

Figure 1. Location of babbler project works and other landcare works implemented since 1996 in the Sheep Pen Creek Land Management Group area and the two sub-districts used for the babbler study. (Source TFNVic)

Introduction: The Grey-crowned Babbler (Pomatostomus temporalis) (babbler) is a threatened woodland bird (classified as Endangered in the state of Victoria) that has declined substantially in overall distribution and abundance across much of its former range in southeastern Australia since European settlement.  Sheep Pen Creek Land Management Group area, in northern Victoria (Fig 1), was fortuitously the location of the largest known remaining babbler population in Victoria in the early 1990s (when this project began); and the focus of extensive land restoration programs from the 1980s onwards to help mitigate the impacts of erosion and dryland salinity, as well as biodiversity decline.  The original study, published in 2006, investigated the overall changes in tree cover across the district between 1971 and 1996 as a result of different land-management actions and responses of local babbler populations to those habitat changes.  The key finding was that in the Koonda sub-district which had a 5% overall increase in tree cover to 14% from 1971 to 2001, showed an increase in babbler numbers by about 30% (Table 1).   In the Tamleugh sub-district, tree cover increased by 1.3% to a total of 9%, with no change in babbler numbers.  The findings also showed that new babbler groups were preferentially colonizing new patches of vegetation established that suited their habitat needs.  Building on this research, the study concluded that future conservation programs needed to scale-up the extent of habitat restoration, target areas which were suitable for babbler colonization, and tailor incentive programs to assist with conservation of particular species.

Table 1. Changes in Grey-crowned Babbler numbers over time

Year Koonda Tamleugh
number of groups number of birds number of groups number of birds
1992 20 78 11 39
1993 20 89 10 34
1996 24 96 9 35
1997 24 102 8 30
1998 25 99 10 40
2000 26 97 10 43
2005 23 99 8 34

Further revegetation works undertaken. Since the initial study’s assessment of vegetation changes between 1971 and 1996, an additional 133 ha of vegetation has been restored or established as babbler habitat in Koonda district and 37 ha in the Tamleugh district (Figs 2 and 3, Table 2).  Extensive natural regeneration, supplemented by broadscale revegetation, has also occurred over more than 350 ha on five private conservation properties in the Koonda district,, contributing to substantial landscape change.  The wider landscape has also been identified as a statewide priority for nature conservation on private land, leading to increased conservation investment in permanent protection there by Victoria’s lead covenanting body – Trust for Nature.

Monitoring of outcomes: The monitoring that was carried out prior to the 2006 publication has not continued, leaving a knowledge gap as to how the population has fared in the context of the Millenium Drought and ongoing climate-change impacts. However, based on the original research’s initial findings, we conducted an experimental study with University of Melbourne to evaluate the effectiveness of habitat restoration in maintaining babbler survival. The study, published by Vesk and colleagues in 2015, compared the persistence and group size of babbler groups present in 1995 and subsequently in 2008 at a randomly selected set of stratified sites which had either had habitat works or none.  This study was conducted across a larger landscape of about 200,000 hectares which included Sheep Pen Creek Land Management Group area.  The study found that babbler group size decreased by about 15% over the 13 years at sites without restoration works.   At sites with restoration, average group size increased by about 22%, thereby effectively compensating for the overall reduction in numbers reported over that time.This increase also influenced subsequent demographic performance, with groups at restoration sites having higher breeding success and more fledglings than groups at control sites.

Another useful finding from this experimental study was the confirmation of the importance of particular habitat and landscape variables on babbler persistence.  In particular, abundance of large trees was a positive predictor of occupancy over time; and distance from the next nearest group was a negative predictor.

Figure 2. Changes in tree cover in the Koonda sub-district between 1971 (top),  and 2018 (bottom). (Source TFNVic).. (Source TFNVic)

Figure 3. Changes in tree cover in the Tamleugh sub-district between 1971 (top) and 2018 (bottom). (Source TFNVic)

Table 2.  Summary of additional habitat established or restored as part of the Sheep Pen Creek Grey-crowned Babbler project from 1996-2018, following the initial study period from 1971-1996.

District Number of sites Area (ha)
Koonda 62 133
Tamleugh 28   37
Other parts of landcare group and local babbler population area 29 103
Totals 119 273

Expansion of lessons to other districts: Building on the fundamental research conducted in Sheep Pen Creek Land Management Group area, similar habitat, landscape and babbler population assessments were subsequently undertaken in northwest Victoria near Kerang for the babbler populations found there.  Key results from these studies relevant to the initial Sheep Pen study were that the number of babbler groups in each sampled district was positively related to the proportion of woodland cover, especially the proportion of Black Box (Eucalyptus largiflorens) woodland habitat – the babblers’ preferred habitat in this region.  Conversely, the number of babbler groups was negatively associated with the proportion of land under intensive agriculture.  At the site scale, key positive predictors of babbler presence in Black Box habitat again included the abundance of large trees (> 60 cm dbh)

Lessons learned and future directions: The most valuable lesson learned since the initial paper was published was the power of the structured research project described above to evaluate the effectiveness of the babbler conservation program and inform future design and planning. The study further demonstrated the importance of taking a demographic approach to the species’ conservation needs, understanding what is happening across the whole population over time  and how habitat interventions can assist.  These lessons have since been applied usefully to other babbler projects  and more broadly to conservation of woodland birds.

The initial paper noted the importance of achieving landscape-scale change in vegetation extent, particularly in more fertile habitats. This has occurred to some extent within the Koonda district through a range of incentive programs, tender programs, covenanting programs and land purchase, but continues to achieve most gains on more infertile land. On fertile land, by contrast, there has been rapid land-use change to cropping over the past fifteen years, leading to reduced likelihood of those properties providing suitable habitat for babblers, as found in the study conducted in northwest Victoria.

The initial paper also suggested the benefit of developing tailored incentive programs for babblers and other threatened species with particular requirements to maximize potential conservation gains  and we suggest, based on Australian and overseas experiences,  that more specific incentive programs or more detailed criteria could assist.

Another important lesson learned was the difficulty in maintaining community-driven citizen-science monitoring, even with the best will in the world, without some over-arching organizational support and oversight.  We know that community monitoring for biodiversity conservation needs scientific input at the design and analysis stages; hence additional resources may also be required in terms of equipment or guidelines to help groups monitor effectively.  Modest government investments to conservation organisations with established biodiversity monitoring programs could usefully help address this issue.

Finally, the learnings from the Sheep Pen Creek Land Management babbler conservation project over nearly thirty years are that the landscape changes and that these changes are not always positive.  Land-use change is placing more pressure on  potential babbler habitat; and the eucalypt regrowth which was established and provided new nesting resources for a few years is now too tall to provide nesting habitat, but too dense and immature to provide suitable foraging habitat for another one hundred years.  Climate change is rapidly imposing constraints on the availability of food resources and breeding opportunities, exacerbated by increased competition for the same limited resources by exotic and native species.  For the Grey-crowned Babbler, the solution to all of these factors depends on ongoing commitment to the establishment or maintenance of their essential habitat needs and life-history requirements so that their life-cycle is provisioned for from generation to generation.

Stakeholders and Funding bodies:   Most of the targeted habitat works achieved for babblers in this landscape has occurred through funding support from the Australian government through its Natural Heritage Trust and Caring for our Country programs.  Broader habitat protection and restoration has occurred primarily with funding support to landholders from the Goulburn Broken Catchment Management Authority (GBCMA).  The Norman Wettenhall Foundation, along with GBCMA, was instrumental in enabling the research by University of Melbourne, which was also aided by the extensive voluntary support of Friends of the Grey-crowned Babbler.  Not least, local landholders continued to support the project and continue to protect or restore parts of their properties to assist with babbler conservation.

Contact information: [Doug Robinson, Trust for Nature, 5/379 Collins Street Melbourne, Victoria 3000, Australia.  dougr@tfn.org.au, (03) 86315800 or 0408512441; and  School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.

 

 

 

 

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Posted in agricultural lands, Community involvement, Cultural & socio-economic issues & solutions, Ecosystem services, EMR 20th anniversary updates, Erosion issues & solutions, Fauna & habitat, Integrating ecosystems & industries, Landscape pattern & design, reconstruction, Restoration & management theory, Sclerophyll communities, Victoria

Monitoring the Wunambal Gaambera Healthy Country Plan, Kimberley, Western Australia – UPDATE of EMR feature

Posted on 14 September 2019 by | Comments Off on Monitoring the Wunambal Gaambera Healthy Country Plan, Kimberley, Western Australia – UPDATE of EMR feature

[Update to EMR feature: Moorcroft, Heather, Emma Ignjic, Stuart Cowell, John Goonack, Sylvester Mangolomara, Janet Oobagooma, Regina Karadada, Dianna Williams and Neil Waina (2012) Conservation planning in a cross‐cultural context: the Wunambal Gaambera Healthy Country Project in the Kimberley, Western Australia,  Ecological Management & Restoration, 13:1, 16-25. See https://doi.org/10.1111/j.1442-8903.2011.00629.xk]

Key words: conservation planning, participatory conservation, Indigenous people, Kimberley

Figure 1. Location map of Wunambal Gaambera land and sea country. (Source: WGAC)

Introduction. The development of the Wunambal Gaambera Healthy Country Plan (HCP) was a key enabler for Wunambal Gaambera people to look after country (Fig 1) and occurred at an important time when native title rights to country were being secured. The plan came about through a partnership between Wunambal Gaambera Aboriginal Corporation (WGAC) and Bush Heritage Australia (BHA), who brought the planning approach and supported WGAC to develop a plan that met the needs of Traditional Owners. This plan then became the basis of a long term partnership between the two organisations to support implementation.

Healthy Country Planning, a term coined by this project, adapted the Open Standards for the Practice of Conservation (http://cmp-openstandards.org/ ) to an Indigenous native title community context. The approach has subsequently flourished in Australia, adopted by a further 30 indigenous groups ( see doi: 10.1111/emr.12267).

The unique partnership model established between BHA and WGAC, underpinned by Healthy Country Planning, has also expanded (https://www.bushheritage.org.au/what-we-do/aboriginal-partnerships). The program supports indigenous partners to achieve their community and conservation aspirations articulated through Healthy Country Planning.

Figure 2. Terrick Bin Sali handling a northern quoll (Dasyurus hallucatus). (Photo WGAC)

Conservation planning with a difference. Our experience has been that the Open Standards can be successfully applied to an Indigenous context but some important adaptation is required. For example:

  1. People, culture and country are inseparable in Australian indigenous worldviews. As such, Healthy Country Planning is much wider in scope than mainstream conservation or natural resource management planning. The vision in the HCP typically sets long-term goals that include aspirations for looking after country and achieving health conditions for landscapes, seascapes, plants and animals, as well as for people and culture (Figs 2-4). These outcomes are collectively referred to as “Healthy Country”. An indigenous plan will always recognize and value people in the landscape rather than as separate. Traditional Owners, and/or their culture, become a conservation target alongside species and habitats with ‘key cultural attributes’ established alongside ‘key ecological attributes’. HCPs also have a greater degree of management strategies that relate to people and culture than would be found in mainstream management plans, and culture and Indigenous Knowledge is incorporated into land management activities that could be considered mainstream, such as the inclusion of cultural rules within visitor management.
  2. The Open Standards include approaches and tools for stakeholder participation that lend themselves well to Indigenous peoples, however given that Indigenous lands are communally-owned and governed by unique law and culture systems, participation requirements are higher and more complex. Traditional systems of governance are often recognized under State and Federal Law (such as the Native Title Act) requiring additional process steps. In developing the HCP, WGAC undertook a process of involving all Traditional Owner families in various stages of planning and the plan was authorized at a Traditional Owner meeting.
  3. A Healthy Country Plan typically applies to the whole traditional estate of a Traditional Owner group regardless of tenure, consistent with the concept of “Country-based Planning”. WGAC initially dedicated stage I of the Uunguu Indigenous Protected Area over several aboriginal reserves in 2010, and later added exclusive possession lands following native title determination. The marine environment will also be added to the IPA once agreement is reached with State and Commonwealth Governments, as articulated in the Uunguu Wundaagu Plan.

Figure 3. Traditional Owners undertaking a ‘junba’ traditional dance workshop. (Photo: WGAC)

Monitoring & evaluation since 2012. Aspects of the monitoring and evaluation framework established by WGAC include the establishment of the Uunguu Monitoring & Evaluation Committee (UMEC) and the completion of mid-term evaluation of the HCP (see 2017 review doi:10.1111/emr.12257). The UMEC is composed of Traditional Owners and external experts who undertake key Healthy Country Planning steps and functions. A significant investment of time and money was required to support annual or biennial meetings “on country” (ie. on Wunambal Gaambera lands), however the review showed that the investment has proven worthwhile because WGAC has been able to implement the plan to a high degree.

In 2015 a major mid-term evaluation was undertaken to assess the progress of the HCP. It utilized some standard evaluation tools examining Open Standards process. It also incorporated some new approaches to include the views of the wider Traditional Owner community in the evaluation of the plan to ensure the plan was meeting their needs and following effective process with regard to governance and participation. The review made a number of observations as follows.

  1. Considerable progress had been made in the implementation of fire management strategies in the HCP to the point that the health condition of the “Right Way Fire” target was changed from ‘fair’ to ‘good’. Unmanaged wildfires have significantly reduced in size as a result of increased capabilities of the Uunguu Rangers to undertake burning. At the same time “right way” cultural principles have been incorporated into operations to ensure that Traditional Owner families are making decisions about burning and undertaking fire operations on their family areas.
  2. Significant progress has been made against a visitor management strategy. One of the key concerns of elders when developing the plan was unregulated visitation to important cultural sites by the expedition cruise industry and independent travelers. The Uunguu Visitor Pass, launched in 2017, requires visitors to obtain a permit to access authorized visitor locations as well as generating funds for looking after country. Over 90% of commercial tour operators have now registered for the UVP, with a similar independent traveler compliance, generating funds to support Traditional Owner participation in visitor management and delivering tour products.
  3. Progress was not made, however, in the health of cultural targets in the plan. As a result, the 2015 review recommended further investment and effort in culture strategies. Two important books have been completed to document elders’ knowledge of biodiversity and cultural places. There has been an increase in cultural activities including language and corroboree dance workshops and annual culture camps for school children. Law and culture dictates that visitors to country (indigenous or non-indigenous) need to be accompanied by the right local Traditional Owners when undertaking activities on country. In this way Healthy Country work supports large numbers of Traditional Owners to visit country and guide participation in the implementation of the plan. A number of actions have been undertaken to support Traditional Owners to live on country and remote ranger infrastructure has been developed.

Figure 4. Uunguu Rangers during a cultural fire walk. (Photo WGAC)

Future Directions. The first 8 years of the HCP implementation has focused on building WGAC’s land and sea management capacity and resources, with funding from WGAC,  the Australian Governments Indigenous Protected Area and Indigenous Ranger Programs and from Bush Heritage Australia. Traditional Owners currently hold certificate level roles of rangers, tourism workers and construction workers but further work is now needed to support Traditional Owners to take on roles that require higher levels of training. There is also a need to support the development of a wider range of livelihoods to support Traditional Owners to live and/or work on country.

Contact information. Wunambal Gaambera Aboriginal Corporation, PMB 16 Kalumburu via Wyndham WA 6740, Australia.

Email: info@wunambalgaambera.org.au

Web: www.wunambalgaambera.org.au

Facebook: https://www.facebook.com/uunguulife/

 

 

 

 

 

 

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Posted in arid, Coastal & marine, Community involvement, Cultural & socio-economic issues & solutions, Fauna & habitat, Fire Ecology & Management, Indigenous Knowledge, Indigenous land & sea management, Integrating ecosystems & industries, Monitoring, Planning, monitoring & assessment, Reserve management, Restoration & management theory, Threatened species & communities, Western Australia

Developments in Big Scrub Rainforest Restoration: UPDATE of EMR feature

Posted on 14 September 2019 by | Comments Off on Developments in Big Scrub Rainforest Restoration: UPDATE of EMR feature

Tony Parkes, Mark Dunphy, Georgina Jones and Shannon Greenfields

[Update of EMR feature article: Parkes, Tony, Mike Delaney, Mark Dunphy, Ralph Woodford, Hank Bower, Sue Bower, Darren Bailey, Rosemary Joseph, John Nagle, Tim Roberts, Stephanie Lymburner, Jen Ford and Tein McDonald (2012) Big Scrub: A cleared landscape in transition back to forest? Ecological Management & Restoration 12:3, 212-223. https://doi.org/10.1111/emr.12008]

Key words: Lowland Subtropical Rainforest, ecological restoration, seed production, landholder action, corridors

Figure 1a. Rainforest regenerators undertake camphor injection, leaving bare trees standing creating light and an opportunity for seed in the soil to naturally regenerate. (Photo © Envite Environment)

Figure 1b Aerial photo showing camphor conversion by injection
(Photo © Big Scrub Regeneration Pty. Ltd.)

Introduction. The Big Scrub, on the NSW north coast, was once the largest tract of Lowland Subtropical Rainforest (LSR) in Australia. It was reduced to less than 1% of its original extent by he end of hte 19th century after clearing for agriculture. Big Scrub Landcare (BSL) is a non-profit organisation dedicated to improving the long-term ecological functionality of what remains of this critically endangered ecosystem –  lowland subtropical rainforest.  Our 2012 EMR feature reported on remnant restoration and revegetation works overseen by BSL to 2012. At that time, 68 remnants were identified as significantly affected from the impacts of environmental degradation including weed invasion and cattle access. These remnants had been undergoing treatments, with 20 substantially recovered and on a ‘maintenance’ regime.  Approximately 900,000 trees had been planted to establish 250 ha of young diverse well-structured rainforest.  A comparatively small area of forest dominated by the highly invasive exotic, Camphor Laurel (Cinnamomum camphora) (Camphor), which  has colonised much of the Big Scrub landscape had been converted to early phase LSR by skilled removal of a range of weeds and facilitating natural regeneration. 

Progress since 2012. Substantial progress in restoring critically endangered lowland subtropical rainforest in the Big Scrub has been achieved over the past seven years in the following areas.

  • Assisted regeneration of remnants has continued and become more focused
  • Re-establishment of LSR through plantings has expanded
  • Camphor conversion has developed in scale and techniques
  • Greater security of funding has been achieved
  • Community engagement has greatly improved and expanded
  • Genome science is being applied to produce seed with optimal genetic diversity for rainforest restoration.

Assisted regeneration of remnants. This work continues to be the major focus of on-ground restoration work. About 2000 regenerator days (9 years Full Time Equivalent) of work has been undertaken in 45 remnants. BSL’s remnant restoration program has become more strategic, with more focus on Very High Conservation Value (VHCV) remnants, particularly those in the NSW National Parks Estate, including the VHCV sites in Nightcap National Park (NP) including Big Scrub Flora Reserve, Minyon Falls and Boomerang Falls; Andrew Johnston’s Scrub NR; Snow’s Gully Nature Reserve (NR); Boatharbour NR; Victoria Park NR and Davis Scrub NR, plus the Booyong Flora Reserve. Rehabilitation work at these sites is prioritised in the major new four-year Conservation Co-funding project funded jointly by BSL and the NSW government’s Saving our Species program. Big Scrub Foundation (BSF) funding has enabled BSL to continue maintenance work in remnants that have reached or are approaching the maintenance stage.

Monitoring outcomes has become more rigorous and has demonstrated ongoing improvements in vegetation structure, with decreasing levels of weed invasion and improvements in native species cover.

BSL’s partner Envite Environment, with some assistance from BSL, is creating an important linkage between Nightcap NP and Goonengerry NP by the restoration of rainforest through the progressive removal of weeds that had dominated the 80 ha Wompoo/Wanganui corridor between these two NPs.

 Re-establishment of rainforest by planting. The area of LSR is being re-established by planting on cleared land has also continued to expand.   In the last 7 years  more than 0.5 million rainforest trees have been planted in the Big Scrub region, contributing to the restoration of another 175 ha of LSR, expanding total area of re-established rainforest by another 13%. While landscape-scale landholder driven work is inevitably opportunistic rather than strategic, the establishment of new patches of LSR enhance valuable stepping-stone corridors across the Big Scrub. Since 2012 the number of regenerators working fulltime in the Big Scrub region has increased by approximately 50%.  Another trend that has strengthened in the last 7 years is that larger plantings are now being carried out by well-resourced landowners. This is accounting for about 40% of the annual plantings. Offsets for residential development account for another 40% of trees planted. The remaining 20% is made up by small landowners, cabinet timber plantations, large-scale landscaping, and other planting of Big Scrub species. This is a significant change from the more dominant grant-based small landowner/Landcare group plantings prior to 2012.

 Camphor conversion. Larger areas of Camphor forest are being converted to rainforest, with project areas increasing substantially from less than a hectare to ten and twenty hectares. BSL estimates that more than 150 ha of Camphor forest are currently under conversion. Some landowners underake camphor injection which leaves bare trees standing, creating light and an opportunity for existing native seedlings and seed in the soil (or seed dropped by perching birds) to naturally regenerate (Fig 1). Others are choosing the more expensive option of physically removing the Camphor trees and carefully leaving the rainforest regrowth (Fig 2).  Improved techniques and landholder capacity building continue to progress and camphor conversion is now a significant component of rainforest restoration.

BSL alone is facilitating the conversion of almost 40 ha of Camphor forest to LSR funded by two 3-year grants from the NSW Environmental Trust, together with contributions from the 19 landholders involved in these projects. The ecological outcomes being achieved are significant and less costly than revegetation via plantings.

Figure 2a. Camphor forest under conversion using heavy machinery leaving rainforest regrowth intact (Photo © Big Scrub Landcare)

Figure 2b. Aerial photo showing camphor conversion by removal
(Photo © Big Scrub Landcare)

Greater security of funding. Australian Government funding for biodiversity conservation is at a very low level. Competition for existing NSW state government funding is increasing. BSL therefore has continued to  develop new strategies for fund raising to ensure continuity of its long-term program for the ecological restoration of critically endangered LSR in the Big Scrub and elsewhere. Ongoing funding of at least $150,000 annually is needed to ensure the great progress made  over the past 20 years in rehabilitating remnants is  maintained and expanded to new areas of large remnants. These funds finance weed control and monitoring; weeds will always be a part of the landscape and an ongoing threat to our rainforest remnants.

Establishment of the Big Scrub Foundation in 2016 was a major development in BSL’s fund raising strategy. The Foundation received a donation of AUD $1M to establish a permanent endowment fund that is professionally invested to generate annual income that helps finance BSL’s remnant care program and its other activities. Generous donors are also enabling the Foundation to help finance the Science Saving Rainforest Program.

Figure 3a. Australian gardening celebrity Costa Gregoriou at a Big Scrub community tree planting (part of the 17th annual Big Scrub Rainforest Day) in 2015 (Photo © Big Scrub Landcare)

Figure 3b. Founder of the Australian Greens political party Bob Brown and Dr. Tony Parkes at the 18th annual Big Scrub Rainforest Day in 2016. (Photo © Big Scrub Landcare)

Community engagement. The  Big Scrub Rainforest Day continues to be BSL’s  major annual community engagement event, with the total number of attendees estimated to have exceeded 12,000 over the past 7 years; the 2016 day alone attracted more than 4000 people (Fig 3). Every second year the event is held at Rocky Creek Dam.  A new multi-event format involving many other organisations has been introduced on alternate years.

BSL’s Rainforest Restoration Manual has been updated in the recently published third edition and continues to inform and educate landowners, planners and practitioners.

BSL in partnership with Rous County Council produced a highly-commended book on the social and ecological values of the Big Scrub that has sold over 1000 copies. BSL’s website has had a major upgrade: its Facebook page is updated weekly; its e-newsletter is published every two months. BSL’s greatly improved use of social media is helping to raise its profile and contribute to generating donations from the community, local businesses and philanthropic organisations to fund its growing community education and engagement work and other activities.

Science saving rainforests program. BSL, the Royal Botanic Gardens Sydney, the BSF and their partners have commenced an internationally innovative program to apply the latest DNA sequencing and genome science to establish plantations to produce seed of key species with optimal genetic diversity for the ecological restoration of critically endangered lowland subtropical rainforest. This program will for the first time address the threat posed by fragmentation and isolation resulting from the extreme clearing of Australia’s LSR, which is estimated to have resulted in the destruction of 94% of this richly biodiverse Gondwana-descended rainforest.

Many  key  LSR species are trapped in small populations in  isolated remnants  that  lack the genetic diversity needed to adapt and survive in the long term, particularly faced with climate change Necessary  genetic diversity is also lacking in many key species in the 500 ha of planted and regrowth rainforest. The first stage of the program, already underway, involves collecting leaf samples from approximately 200 individual old growth trees in 35 remnant populations across the ranges of 19 key structural species of the ‘original’ forest. DNA will be extracted from the leaf samples of each species and sequenced. The  latest genome science will be applied to select the 20 individual trees of each species that will be cloned to provide planting stock with optimal genetic diversity for the establishment of a living seed bank in the form of a plantation that will produce seed  for use in restoration plantings. As the individual trees in the restoration plantings reproduce, seed with appropriate genetic diversity and fitness will be distributed across the landscape. The project focuses on key structural species and thus helping the survival of Australia’s critically endangered Lowland Subtropical Rainforest in the long term.

Lessons learned and current and future directions. A key lesson learned some five years ago was that BSL had grown to the point where volunteers could no longer manage the organisation effectively. BSL took a major step forward in 2015 by engaging a part-time Manager, contributing to BSL’s continuing success by expanding the scope, scale and effectiveness of its community engagement activities and improving its day to day management.

The principal lesson learned from BSL’s on-ground restoration program is to focus on rehabilitation of remnants and not to take on large planting projects, but rather support numerous partnered community tree planting events. Large grant-funded multi-site tree planting projects are too difficult to manage and to ensure landholders carry out the necessary maintenance in the medium to long term.

Acknowledgements.  BSL acknowledges our institutional Partners and receipt of funding from the NSW government’s Saving our Species program, NSW Environmental Trust and Big Scrub Foundation.

Contact:  Shannon Greenfields, Manager, Big Scrub Landcare (PO Box 106,  Bangalow NSW 2479 Australia; . Tel: +61 422 204 294; Email: info@bigscrubrainforest.org.au Web: www.bigscrubrainforest.org.au)

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Posted in agricultural lands, Assisted regeneration, Bush regeneration, Community involvement, Cultural & socio-economic issues & solutions, Education & communication, EMR 20th anniversary updates, Fauna & habitat, Genetic issues, Landscape pattern & design, New South Wales, Rainforest, reconstruction, Restoration & management theory, Techniques & methodology, Weed issues & solutions

Seagrass restoration off the Adelaide coast using seeds and seedlings – UPDATE of EMR feature

Posted on 25 August 2019 by | Comments Off on Seagrass restoration off the Adelaide coast using seeds and seedlings – UPDATE of EMR feature

Jason Tanner

[Update of EMR feature article :  Tanner JE, Andrew D. Irving, Milena Fernandes, Doug Fotheringham, Alicia McArdle and  Sue Murray-Jones (2014) Seagrass rehabilitation off metropolitan Adelaide: a case study of loss, action, failure and success.Ecological Restoration & Management 15: 3, 168-179.  https://onlinelibrary.wiley.com/doi/10.1111/emr.12133]

Key words:  Amphibolis, Posidonia, Recruitment facilitation, Seagrass loss

Figure 1: Bag layout for small-scale experiments on Amphibolis recruitment facilitation (top left), Amphibolis seedlings (top right), close-up of basal ‘grappling hook’ that allows seedlings to attach (bottom left), and examples of older style double-layered bags with and without seedlings attached (bottom right).

Introduction: Over the last half century or so, over 6,000 hectares of seagrass has been lost off the Adelaide coast due to anthropogenic nutrient and sediment inputs.  This loss has led to coastal erosion, decreased habitat, loss of carbon storage, and decreased fish abundance.  Recent improvements to wastewater treatment and stormwater runoff have led to some natural recovery, but changes in sand movement resulting from the loss now prevent recolonization of many areas.  Our September 2014 feature article in EMR described how SARDI have been working with other state government agencies and universities to develop a cost-effective technique to restore these areas.  Typical seagrass restoration costs on the order of AUD$1 million per hectare, but by facilitating natural recruitment of Amphibolis, yet over the last 17 years we have developed a technique that only costs a few tens of thousands of dollars.  As described in the feature, this technique uses hessian sand bags (Fig. 1) to provide a stable recruitment substrate while seedlings become established, and has resulted in the re-establishment of small trial patches of seagrass restoration (10-100 m2) which are now over 10 years old (Fig. 2) Importantly, these sites have been colonized by Posidonia and Zostera seagrasses, and provide habitat for faunal assemblages that are similar to those of nearby natural meadows, suggesting potential for small plots to act as ‘starters’ for ecosystem recovery.

Figure 2: Examples of Amphibolis restoration showing progression of establishment from 12 months (top left), 41 months (top right), 58 months (bottom left) and 8 years (bottom right).

Further work undertaken: Since our original article in EMR, we have continued monitoring the 1 hectare trial patches and expanded our focus to include additional species in the restoration, especially Posidonia.  We have also started assessing how bags degrade over time under different storage conditions, as operationalizing this technique will require bags to be stored potentially for a month or more between filling and deployment.  Importantly, the SA Government has now allocated funds for a proof of application, which will involve the deployment of hessian bags over approx. 10 hectares in late autumn 2020.

Further results to date: Two 1 hectare trials were deployed in June 2014, with 1,000 bags in each (Fig. 3).  After 9 months, these bags had an average 6.2 Amphibolis seedlings each, which was typical for bags deployed outside the winter recruitment season in previous years.  After a further 12 months, this increased to 9.2 seedlings per bag, within the range of densities previously seen for small-scale winter deployments (7-23 seedlings per bag).  A further 12 months later, densities had decreased to 3.1 seedlings per bag.  In 2017, a third 1 hectare trial was established with 2,500 bags, although these bags only had 1.2 seedlings each after 9 months. Unfortunately loss of nearly all marker stakes on all three plots due to suspected disturbance by fishing gear meant that further monitoring was not possible.  It should be noted that for the successful small-scale deployments, stem densities between 2 and 5 years were very low, and it was only after 5-7 years that success was evident.

Planting Posidonia seedlings into the bags showed good success over the first 3-4 years, with seedlings becoming established and developing into what appeared to be adult plants with multiple shoots, which did not allow individual seedlings to be identified (Fig. 4).  However, leaf densities declined substantially in the 12 months following the February 2016 survey, and recovery has been slow in the 2 years since.  Trials with different fill types (different sand/clay mixes, different amounts of organic matter added) indicated that this did not influence establishment success or growth, and neither did planting density.  Small and large seeds, however, tended to fare poorly compared to those of intermediate size (10-13 mm).  These results have been supported by short-term tank experiments, which also showed that there is only a short window for collecting fruits (those collected on 28 Dec formed an average 3.3 120 mm long leaves each after 2 ½ months, while those collected 6 days earlier or 3 days later formed < 2 leaves which were no more than 80 mm long).  After collection, fruits that did not release their seedling within 2-3 days performed poorly, and seedlings were best planted within 10 days of release. Whilst earlier Posidonia field experiments were undertaken by divers planting seedlings, which is time consuming and expensive, in 2017 seedlings were planted either onshore or on the boat, and then glued into the bags prior deployment.  This was as successful as planting underwater after 1 and 2 years, with an average 20% seedling survival, and leaf lengths of 20-25 cm, across all treatments.

Bags filled with moist sand rapidly dried out in storage, and did not deteriorate any quicker than those filled with dry sand, although it should be noted that in this experiment all bags had good air circulation around them, which would not be the case if they were stored in bulk.  Bags left outdoors exposed to the elements deteriorated quicker than those stored indoors, and pallet wrapping led to them rapidly becoming mouldy.

Figure 3: Pallets of sand bags ready for deployment (top left), and typical images of deployment

Lessons learned and future directions:  While the hessian bag method has resulted in the successful establishment of small patches of seagrasses that have persisted for around a decade, and which are now functioning like natural patches due to colonization by other marine plants and animals, the development of the technique has not been straightforward.  Refining the technique has required the development of a good understanding of the timing of recruitment, and the willingness to put conventional wisdom to the test.  This work has also required funders to take a long-term view, and to be willing to accept the fact that success cannot be established within a conventional 3-year funding cycle.  In this case, it was only 5-7 years and 2 funding cycles after deployment that we saw our small-scale trials being successful.  Now that we have established the technique at a small-scale, we are experiencing a new set of challenges with scaling up.  The 1 hectare plots have not been as successful as we had hoped.  In part, this may be due to low bag density – our small-scale plots were equivalent of approx. 10,000 bags per hectare, not the 1,000-2,500 that we have used.  Consequently, our next trial with involve a range of bag densities, from 1,000 to 10,000 bags per hectare.  In our previous article, we had indicated that we were looking at developing novel coatings to improve the life of the hessian bags, however, this proved cost prohibitive and reduced the ability of seedlings to attach to the bags.  Instead, we have now commenced a new collaboration with textile scientists to look at alternative natural fibres that might last longer than hessian but still be cheap, effective and biodegradable.

Stakeholders and Funding bodies:   SA Department for Environment & Water, SA Water, Adelaide & Mount Lofty Ranges Natural Resource Management Board, Australian Research Council, South Australian Research & Development Institute, Flinders University

Contact information: A/Prof Jason Tanner, Principal Scientist – Environmental Assessment & Rehabilitation, SARDI Aquatic Sciences, PO Box 120, Henley Beach, SA. 5022. Tel: +61 8 8429 0119. Email: jason.tanner@sa.gov.au

Figure 4: Example of Posidonia rehabilitation at time of planting (left – January 2012), after 2 years (middle – February 2014) and 4 years (right – February 2016).

 

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Posted in Assisted regeneration, Coastal & marine, EMR 20th anniversary updates, marine, reconstruction, Research summary, Restoration & management theory, South Australia, Techniques & methodology