Margaret Reidy(10 Godfrey Road, Artarmon, NSW 2064, Australia. Email: firstname.lastname@example.org) has been a volunteer in the Park since 1992 when the Bushcare program was launched in 1994. She is an inaugural member of the Friends of Lane Cove National Park (http://users.bigpond.net.au/folcnp/) and has been its President since 1995.Winkie Chevalier(243 Miller St, North Sydney, NSW 2060, Australia.) is also an inaugural member of the Friends group and has been a volunteer with the Bushcare program since 1993.Tein McDonald(P.O. Box 42, Woodburn, NSW 2472, Australia. Email: email@example.com) assisted with initial assessment of post-fire regeneration and prioritization of work sites in 1994.
Lane Cove National Park Bushcare volunteers: Taking stock, 10 years on
Version of Record online: 30 JUN 2005
Ecological Management & Restoration
Volume 6, Issue 2, pages 94–104, August 2005
How to Cite
Reidy, M., Chevalier, W. and McDonald, T. (2005), Lane Cove National Park Bushcare volunteers: Taking stock, 10 years on. Ecological Management & Restoration, 6: 94–104. doi: 10.1111/j.1442-8903.2005.00225.x
Box 1. Why was a concerted effort made after the fire?
Tipping the balance towards native resilience rather than weed resilience.
The rationale behind the call for community support for on-ground works was the observation that the bushfire had carried out ‘primary treatment’ across a very large area (see Box 2 for definition of terms). This primary treatment extended to moist gullies and highly fertile weed-dominated urban edges, many of which were unlikely to have been subjected to intense fire since the first period of urban construction that led to the development of weeds in these areas.
This fire was thought to have killed a proportion of the weeds in these areas while triggering much of the remaining rootstocks and weed seed banks to regenerate; ‘flushing out’ weed to a high degree. However, the wildfire also triggered massive germination from long-buried seedbanks of fire-adapted native species (see Box 3).
The regeneration project was instigated for the following reasons. It was considered by regenerators that if the opportunity was not taken up to control weeds at this point, they would proliferate and smother natives before the natives could recharge their own seedbanks; potentially causing the sites to regress to even more degraded states than prior to the burn. In contrast, if weeds were controlled during the period required for the natives to dominate the sites, complete their life cycles, and reproduce; the sites could develop a native resilience higher than prior to the burn.
Box 2. What are ‘primary’ and ‘secondary’ treatments?
In bush regeneration terms, ‘primary treatment’ is the first weeding treatment at a site – the one that removes the ‘parent’ generation of weed. As it creates new gaps for emergence of weed stored as seed in the soil, multiple ‘secondary treatments’ may be required to deplete weed sufficiently to allow the pre-existing native vegetation to fill the gaps (Buchanan 1990).
Limited resources for the work dictates that the area subjected to primary treatment by a regeneration team needs to be carefully limited to that area which the team can reliably re-treat multiple times (; Buchanan 1990). This is because regenerators have found that taking on too large an area can lead to inability to follow up, which in turn can lead to much higher densities of weed and a more highly charged weed seedbank than prior to the primary treatment.
Box 3. Natives and weeds emerging within the Lane Cove catchment after the fire
The germination response of native species to fire was assessed at 16 degraded sites and four adjacent burnt but otherwise healthy reference sites 6 months after the wildfire ()**. The degraded sites were selected by bush regenerators as their ‘best’ examples of recovery on those sites which, prior to the fire, could be classed as having medium to very high weed domination. Data collected from 40 random (25 m2) quadrats in in these sites (eight per condition class) showed that the degraded sites typically contain resprouting privets (Ligustrum lucidum and L. sinense), and a dense suite of germinating annuals including Fleabane (Conyza spp.), Paddy's Lucerne (Sida rhombifolia), Ink Weed (Phytolacca octandra), Black Nightshade (Solanum nigrum), and exotic grasses. These species are typical of weed associations in higher fertility sites within the Sydney area (Adamson & Buchanan 1974; Adamson & Fox 1982; Buchanan 1990). Other sites contained Lantana (Lantana camara), while on floodplains, weed vines such as Balloon Vine (Cardiospermum sp.) and Turkey Rhubarb (Acetosa sagittata) occurred.
[ Relationship between frequency of occurrence and mean stem density for native sclerophyll species regenerating 6 months after the 1994 wildfire in degraded subsites in Lane Cove National Park, Sydney, Australia. Plants surveyed in eight (25 m2) quadrats (from four subsites) in each of five condition classes (total of 40 quadrats). Data from McDonald (1996). Open symbols, obligate seeding species; closed symbols, resprouters. ]
Natives regenerating. Abundant regeneration of natives were found within the quadrats at all sites in all classes of degradation. The vast majority of these were obligate seeding shrub species, particularly those from the Fabaceae family (Table 1). However, some obligate seeding species from the Epacridaceae and Proteaceae families that were represented on the healthy burnt sites were not found on degraded burnt sites. Obligate seeding species were presumably triggered to germinate from long-buried seed banks. Resprouting sclerophyll shrubs were largely absent from the degraded sites, although six resprouting shrub species were found on healthy burnt sites (including Lambertia formosa and Persoonia levis (represented as resprouts only) and Micrantheum ericoides, Hakea laevipes subsp. laevipes, Lomatia silaifolia and Banksia spinulosa (represented both as resprouts and as seedlings)).
Box 4. From the Ridge to the River: Restoring Riparian Habitat in Lane Cove River Catchment
The‘Ridge to the River’ project is a Natural Heritage Trust project within the overall Lane Cove National Park Bushcare program. Its aim is to deal with weed sources in the urban fringes and upper reaches of two small creek catchments (Fern Valley Creek, Carters Creek, and a hanging swamp between them) whose lower reaches were already subject to volunteer Bushcare and some contract bush regeneration work.
While funding was also used for community education and the construction of a sediment basin/wetland at the top of Carters Creek, the main focus was to employ contract bush regenerators. Contractors commenced primary work in Fern Valley in May 2000 by targeting an extensive area of Large-leaved Privet, Small-leaved Privet and Winter Senna (Senna×pendula). Medium specimens were cut and the stems painted with herbicide while mature trees were injected with herbicide and left standing to maintain habitat and creekline stability. Other weeds removed included Montpellier Broom (Genista monspessulana) and Blackberry (Rubus sp.) – with Mistflower (Ageratina riparia), Monbretia (Crocosmia×Crocosmiiflora), and Gladiolus (Gladiolus sp.) removed along the creek lines. In the hanging swamp, privets, Genista, Crofton Weed (Ageratina adenophora), Blue Paspalum (Paspalum quadrifarium), and Cyperus eragrostis were removed carefully and thoroughly, allowing the native Black Bog Rush (Schoenus melanostachus) to consolidate and dominate the habitat.
Follow up and maintenance of the sites is being undertaken by the volunteer groups, who are firmly dedicated to the task. The efficiency of the work is enhanced by the fact that the contract and volunteer teams are supervised by the same person, Lyn Hume, who also ensures (through the volunteer group or her own effort) that funding gaps do not result in lapses in essential follow-up work. TAFE students were involved in some monitoring and are continuing on-ground work targetting exotic species and undertaking secondary work in the area below the caravan park.
Lyn Hulme, summarizes the benefits of this collaborative approach:
The combination of contractors and volunteers is one of the reasons the sites have recovered so quickly – and is particularly important during the January and February period when annuals and species like Mistflower are developing and also there can be a funding gap between projects.
As a result, extensive areas on the two creeks and hanging swamp have now recovered to native vegetation, providing desired habitat for wildlife. Fern Valley creek and its waterfall have now been freed of Privet, Senna, Lantana, Mistflower and Blue and Giant Paspalum. The combined effort of both teams has now secured all the boundaries and escarpment above Carters Creek. No weeds are coming into the valley now from the edges except via urban run-off from the adjacent cemetery. We have further funding to work in a dense privet infestation remaining along the creek line at the top of the valley; and expect this will regenerate well over time as we have found that the sites are highly resilient. With regular checking and thorough follow up, most areas stabilize to a dense native cover within 3 years of the initial weed removal.
Broader community involvement has been sought through information posters in the Park's Display Centre and the mobile educational trailer to promote the project and seek Bushcare volunteers. A successful community Planting Day was held beside the hanging swamp to inform residents of the habitat issues and establish new habitat for the Swamp Marsh Frog known to occur in the site.
Box 5. Community education
One of the aims of the Friends is to disseminate information to the public on conservation issues. This is undertaken in a variety of ways.
• The Friends website – designed and maintained by one of the committee volunteers, the site attracts enquiries about Bushcare, conservation and volunteering from local and overseas searchers (http://users.bigpond.net.au/folcnp/)
• Regular newsletter called Regenavitis combining input from the Park and Friends
• Mobile Education Trailer including displays of weeds and educational material on establishing bush-friendly gardens
• Interpretive display in the Park's Display Centre
• Brochures, posters, signage on habitat for wildlife, water quality and Bushcare
• Friends attending workshops and special events (e.g. Weedbusters Week, Biodiversity month)
• Community work days (e.g. Planet Ark tree planting day)
• Media releases on special issues in local newspapers
- Issue online: 30 JUN 2005
- Version of Record online: 30 JUN 2005
Lane Cove Valley's wildfires of 1994 triggered not only massive regeneration of natives and weeds but also a massive response from bush regeneration volunteers. Is the momentum still positive and what lessons can be learned?