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Case Studies

These case studies are some of the achievements of the Bushcare program and its enthusiastic volunteers...

Where There's Smoke There's Bush...

Oriel Reserve Plaque

Lighting Up

After the Sydney 1994 bushfires, local councils and other land management authorities were put under pressure to create and enact new procedures to protect people and property. The fires burnt out large areas of Willoughby City Councils native vegetation and as a result the council took part in this policy transformation. Vegetation was cleared to create fire breaks, fuel removal took place and a Fire Hazard Reduction Team was formed. The council wisely entrusted Bush Regenerators to manage the activities of the FHR team.

The primary focus of the new council team was to plan, prep and conduct controlled burning in conjunction with the NSW Fire Brigades. Over the years the team’s members, equipment and expertise has increased which has allowed them to perform their smaller burns autonomously. This allowed the bush regenerators, employed by the council, to burn purely for ecological reasons where the fire hazard potential was minimal.

Starting Small

Map of Oriel Reserve's latest action plan. Notice the size of #19 compared to the reserve.

A council employee, working on a Reserve Action Plan for a small reserve, was approached by local Castlecrag residents, with adjacent properties, to start a volunteer group. In June 2004, the new bushcare group, Oriel, was formed. Oriel Reserve, which is less than 1000 sq m, was a Ficus, Pittosporum and Eleocarpus Association with two Angophoras (in poor health), one E. piperita (seemingly healthy) and a Banksia serrata. The native ground cover consisted of ferns and grasses. The major weed problems, apart from the annuals, were spider plant, fishbone fern, wandering jew and Ehrharta erecta.

The bushcare group in consultation with councils Bushland Department suggested two possible courses of action. The first was to allow the Pittosporum dominance to continue and encourage other wet area species to create a mini rainforest. The idea was that it would be in keeping with the natural changes occurring within the reserve and therefore would be easy to maintain. The alternative plan was to try and return the site to its approximate original vegetation. The presence of an older E. piperita and Angophora costata indicated that there could still be some resilience left in the reserve.

The group decided to opt for the second approach, as it was felt that both methods would require the same level of maintenance but the later option had the potential to salvage any of the existing native seed bank. The easiest way to simultaneously cull the Pittosporums and stimulate the germination of native seed left in the soil was to conduct a prescribed burn. The small size of Oriel Reserve dictated that the burn itself would have to be diminutive.

Burning "Weeds"

Though not technically a weed, the Pittosporum undulatum was creating a monoculture within the reserve. The Pittosporums, and to a lesser extant the Blueberry Ash, were chopped down and cut up to allow for the thinner branches to dry more quickly. A platform, using the smaller trunks to create the frame, was constructed and the drying branches, as well as removed fishbone, were piled on top. The elevated vegetation was left for five months to season and then in Jan 2005, it was burned.

Before and after shots of the 2005 burn.

The same corner in 2009, notice the height of the young E. piperita in the centre of the frame and its blackened ancestor to its right.

Crack a Window

Most Castlecrag streets and reserves are named after components of castles as part of Burley Griffin’s vision. The names are not randomly allocated and Oriel Reserve, named for a type of bay window used back in Tudor times, was a nice lookout to Middle Harbor before the area became so densely populated.

The burn occurred just before the window of opportunity closed on the availability of viable canopy seed in the seed bank, as the sick Angophora costata and the seemingly healthy E. piperita died soon after. The short lived seed would have had little hope of being replenished by such unhealthy specimens. The Angophora was unable to leave any offspring but three E. piperitas germinated after the fire.

Some of the regeneration was a result of long lived seed from previous plantings done on the site by locals many years ago. Most of these were endemic Acacia species which helped to transform the site from closed forest to open woodland.

The most exciting species to reappear, besides the piperitas, were Viminaria juncea, Crowea saligna, Platysace linearifolia and Goodenia heterophylla. These specimens were able to flower and seed, ensuring there continuing presence in the reserve.

Examples of natural regeneration at Oriel post fire; Crowea saligna, Viminaria juncea, Acacia terminalis and Platysace linearifolia.

Keep the Flame Lit

Another burn was carried out in 2006 in even less resilient areas and unfortunately but unsurprisingly nothing very interesting germinated naturally. However, the lacklustre result and the ineffective follow up proved to be very educational. During the post fire weeding, the bracken fern was observed shading out the few Acacia seedlings and harbouring weeds.

Oriel’s 2006 burn the day after and two years on. Notice the bracken dominance. Hidden behind the bracken are five Banksia serrata seedlings

Soon after the burn, the sole Banksia serrata on site lost a branch during a storm. The branch luckily was laden with viable cones and the group decided, rather than have them rot where they lay, to spread them on the newly burnt areas. Twelve Banksias initially germinated and of those five are still alive and thriving. Selective culling of the Bracken was necessary to allow the Banksias to get enough light.

The most successful seedling from the Banksia cones

The most successful seedling from the distributed Banksia cones
Close proximity of private property to Reserve

Notice the proximity of the property on the left in the prepped 2009 burn

A burn, to be conducted in 2009 will take these two discoveries from the 2006 burn into account. We have collected the seed of many local species, mostly peas to broadcast after the burn. The group plans to leave no bracken unmolested during post fire weeding until the midstorey is established. This is not to argue with the fact that the bracken is part of the colonizing succession but when working in reserve with limited space, unusual steps need to be taken in order to achieve maximum diversity.

Pass it on

The group’s latest burn will be the third in the five years of the group’s existence. At the very least a burn provides a “clean slate” for any activities deemed appropriate in a particular work area. Given adequate resources and expertise almost any site can benefit from a little fire.

The 2005 burn was by far the most successful, which is not surprising as it was done in the most resilient area in the reserve. The group has learned to work with what is available and adjust to conditions that are not present in larger more resilient areas.

A very short walk around Oriel today shows that fire, if possible, can be a great start when reforming and reshaping even the most insignificant and unlikely of locations.

"The Drive" Bushcare Site

Area prior to revegetation - March 1998

Mulching completed in preparation for planting - May 1999

Extension to revegetation site - May 2002

Planting day on new extension area - July 2002

Revegetated area in 2005

The site and its conditions

“The Drive” Bushcare site stretches for approximately 200 metres along the northern edge of Flat Rock Gully Reserve, Northbridge. Its vegetation is classified as ‘Coastal Sandstone Heath’ (Open Shrubland) in which Tick Bush (Kunzea ambigua) is the dominant species.

One particular section of “The Drive” Bushcare site is focused on in the description below. It is an area behind a dozen or so houses on Sailors Bay Rd, Northbridge, leading downhill into a bush gully. In the early twentieth century it was a sandstone quarry. One of the local residents, who first came to the area in the late 1940s, said that the area was already a “privet forest” in those days.

When our group started working in this section-about 1994-there was a large strip of annual weeds immediately behind the houses, occasionally mowed. Below that came the Large-leaved Privets (Ligustrum lucidum) and Small-leafed Privets (L. sinese), Lantana (Lantana camara), Honeysuckle (Lonicera japonica), Morning Glory (Ipomoea indica), Mickey Mouse Plant (Ochna serrulata), Camphor Laurel (Cinnamonum camphora) etc. with the odd Cheese Tree (Glochidion ferdinandi), Pittosporum (Pittosporum undulatum) and Lomandra (L .longifolia). As there has never been a fire in this part of the gully the vegetation was virtually impenetrable.

The work we undertook

We started work by trying to remove some of the smaller Privets, vines and Asparagus Fern (Protasparagus aethiopicus) plants, only to find the area was being re-invaded by the aggressive weedy grasses and herbs already flourishing on the border above. We were fighting a losing battle so we changed our tactics. We cleared a strip between the woody weeds and the annual weeds. The area was sprayed with Glyphosate, weed matting was laid and the site was planted out with local species including Peppermint Gum (Eucalyptus piperita) and Sydney Red Gum (Angophora costata) and a range of Acacias. Banksias grown from locally collected seed, were also planted, and then the whole area finally mulched.

When the vegetated strip was established (it took approximately 4 years) we commenced gradually removing Privets. We finally poisoned the larger trees that were previously left to provide shade for regenerating seedlings. All the dead Privets were stacked in piles and allowed to rot on site, providing habitat for the wildlife we hoped to attract. Also, as the wood decayed, it would improve conditions for beneficial micro-organisms in the soil, thereby increasing the site’s biodiversity.

We resisted the temptation to plant into the area, as, on the side of the site, there was a small section of native flora-luckily undisturbed by the quarry workers.

Regeneration results

Initially a small patch of Weeping Grass (Microlena stipoides) spread very quickly into cleared sections followed by other grasses –Basket Grass (Oplismenus imbecilis) and Entolasia Grass- and herbs. We are only a small group but, because we meet three times a month, we were able to give the site some intensive follow-up which has really paid off. Persistent attention to weed grasses in particular has paid off (in spite of discouragement from very persistent, aggressive jumping ants.)

While it is still a ‘work in progress’ 90% of the site has a grass and forb cover. And we are now seeing some small plants appearing such as Acacias, Kunzea, Blueberry Ash (Eleaocarpus reticulatus), Bleeding Hearts (Omalanthus populifolius), Leucopogon sp., Dianellas, Elderberry Panax (Polyscias sambucifolia) and Cheese Trees. Native Sarsparilla (Smilax glyciphylla), Clematis sp., and Hardenbergia (Hardenbergia violacea). The regeneration without the use of fire has been remarkable.

A new area started

In an adjoining area, below yet another new development, we are following the same procedure, but the results are not so far advanced at this stage. This is due to not being able to spend the same amount of time on the project. After removing another mass of Privets and Ochna, with occasional Blackberry (Rubus ulmifolius) and Pampas Grass (Cortaderia jubata), we revealed a large Elkhorn other native ferns, herbs, sedges and other spreading grasses from the edges of the ‘good bush.’ There are emerging signs of good regeneration here too.

Changes to the native fauna

With the change in the vegetation we are aware of a corresponding change in the resident wildlife. In the early days, and at various times, we had a resident domestic rabbit, a few feral cats and their kittens. We had the occasional visit by a fox, and many Indian Mynas invading the bush. Now we feel the native animals are reclaiming their territory. Local birds are constantly entertaining us, including returning Brush Turkeys, Yellow-tailed Black Cockatoos (who feed on the 2 or 3 different types of Hakeas), Superb Fairy Wrens, Red-browed Finches, Golden Whistlers, Eastern Spinebills, King Parrots, Black Faced Cuckoo Shrikes, White-faced Herons, Grey Butcherbird, Wattlebirds, Lorikeets and Sulphur Crested Cockatoos. Snakes (Brown, Red bellied Blacks and Golden Crown Snakes) and Blue Tongue Lizards are plentiful and we have even had an odd sighting of an Echidna. We have unfortunately not seen the return of the Ring tailed Possums which used to inhabit the original “Privet forest.” We are hoping that as the vegetation thickens up they too, will return. (However, it may be that they have just retreated to the thicker, older native vegetation below the site.) Powerful Owls do patrol the area, perhaps they too will roost here one day?

By Joan Viner, convenor of ‘The Drive’ Bushcare group, who has been a member of the group since 1994 with contributions from Shelagh Kemm, long term member of group and Don Swonnell, Council trainer.