Taroona Foreshore Rehabilitation Site Action Plans 2008-2012
PREPARED FOR TAROONA ENVIRONMENT NETWORK
BY north barker ecosystem services
4. Action Plans
The plans list necessary actions, proposed management, priority, and expected outcomes.
The area has been divided into eight zones:
Zone 1: Illawong Reserve
Zone 2: Ralphs Gully
Zone 3: Hinsby Beach
Zone 4: Passionfruit Gully
Zone 5: Niree Parade Foreshore
Zone 6: Taroona Park
Zone 7: Crayfish Point
Zone 8: Nubeena Crescent to Melinga Place Foreshore
4.1. Priority ratings
The actions have been rated in accordance with priority. It is noted that the priorities and programming may be altered as special circumstances arise. For example, this may be due to the lack of certainty with climate, the number of volunteers or the availability of resources.
IA Immediate Action Action to be completed as soon as is practicable
ST Short term Action to be completed within 2 years
MT Medium term Action to be completed within 2-4 years
LT Long term Action to commence after 4 years
The following plans are based on the assumption that there is an average of 10 monthly working bees attended by 8-12 members of TEN.
Other manpower resources include Kingborough Council personnel and periodic use of contractors most notably for using herbicidal spray and machinery. The tasks outlined provide opportunity for Council to allocate resources for this work and to seek funding opportunities
4.2 General recommendations
4.2.1 Photo points
It is recommended that the Taroona Environment Network set up Permanent Photo Points (PPP) at key management sites. These photo points should be photographed annually and the photos stored in a database for future reference. The following sequence is recommended for successful establishment of photo points:
Identify representative sites for photo points.
Identify the PPP site using a marker peg. The pegs make good points from which to photographically document progress of work and regeneration of the site over time.
Record the AMG co-ordinates of the PPP (if possible using a GPS).
Record the direction that the photo should be shot towards from the PPP on the site map (record in degrees using a compass)
Store photos on a database (electronic and/or paper).
Repeat photos to be taken at agreed intervals (eg annually). When framing the photo have previous images at hand to review.
In many instances the use of herbicide has been recommended. The method of application is suggested where appropriate. The type of herbicide should be determined by the target species and the location of infestation. The preferred herbicide is one containing glyphosate that includes a surfactant which has been approved for use near waterways eg Round-up Biactive ®. On occasion other specific herbicides may be required to target particular species. It is recommended that TEN seek advice from a certified weed officer. Herbicide use should be in accordance with Weed Service Sheets (DPIW).
4.3.1 Zone 1 – Illawong Reserve
Zone 1 is Council owned land.
Illawong Reserve is the most significant bushland within the study area, as the area supports moderately healthy native vegetation which connects with a larger bushland system extending south along the Alum Cliffs. The area is in relatively good condition and should respond well to bush regeneration works in the future. The area is bounded by Hinsby Beach (Zone 3) to the east, bushland areas to the south which extend through to Kingston, and residential properties to the west.
The geology is predominantly Qa with Ts at lower levels. Some Jurassic dolerite in steep upper reaches of reserve, near property boundaries.
The bushland is dominated by blue gum Eucalyptus globulus and also contains black gum Eucalyptus ovata and white gum Eucalyptus viminalis. Other prominent native shrubs include prickly box Bursaria spinosa, drooping sheoak Allocasuarina verticillata, blackwood Acacia melanoxylon, native olive Notelaea ligustrina and native cherry Exocarpos cupressiformis.
A major management issue within this zone comes from the large weed plumes which exist below the residential properties along the western boundary of the reserve. This area is very steep and contains dense weed infestations including blackberry, boneseed, cotoneaster, sweet pittosporum and radiata pine. This weed plume extends along the steep slope into the drainage line to the south, where canary broom becomes a major problem. This drainage line, which forms the southern boundary of the zone, flows from within residential areas and is fairly eroded. However there is still some existing remnant vegetation. This includes common dogwood Pomaderris apetala, tasmanian currajong Asterotrichion discolor, blanket leaf Bedfordia salicina, blackwood Acacia melanoxylon and longleaf tall sedge Carex appressa.
Locally natural regeneration is suppressed by the secondary layer of sheoak Allocasuarina verticillata and the associated dense needle litter. This is a natural phenomenon which creates other habitat characteristics which are likely to be favourable to some biota including some invertebrates and other micro organisms. At the landscape scale, tree fall, wildfire and other disturbances contribute to the creation of a multi-aged forest structure. Where vegetation is managed at the small property scale, such as at Illawong Reserve, there is often a desire to replicate the range of habitat attributes more typically distributed over the wider landscape within the confined area of management. At Illawong Reserve the use of fire is undesirable for reasons of safety, aesthetics and impacts to existing and future replanting. Native understorey can be artificially encouraged through direct planting where there is large scale absence of this occurring naturally.
- To control all declared and environmental weeds to stop them from spreading into the adjacent bushland areas.
- To promote habitat for numerous bird and mammal species, as this area is the last area of dense vegetation before the cleared areas in Zone 7.
Summary of Actions
The core areas of the reserve are in relatively good condition with the major problem being woody weeds, primarily boneseed. Cotoneaster, blackberry, polygala and sweet briar are also prominent. There are infestations of annual and herbaceous weeds in the understorey, which if left untreated, tend to take over and become a major management issue. The woody weeds will be relatively easy to treat and should be tackled before the boneseed is allowed to flower and set more seed. It is recommended that a team pass though the entire core area and hand pull or cut and paint all woody weeds as soon as possible. Treating the annual and herbaceous weeds is much more time consuming and will involve the use of a handheld sprayer. The recommended approach is to spend time hand weeding around the edges of native ground covers and graminoids creating an edge of native and weeds. The aim is to keep pushing the native edge out towards the weeds, encouraging it to take over. In areas totally dominated by weeds careful handheld spraying is useful. There are some obvious edges within the reserve, for example there are some clear edges of panic veldtgrass Ehrharta erecta which would be worth weeding to encourage the spread of the native iceplant Tetragonia implexicoma into areas dominated by the weeds.
There are numerous planting areas within the reserve which will require regular maintenance. It is recommended that the planting areas be contained to areas along the boundary and along the track as natural regeneration within the core areas is occurring. Where local regeneration is obviously inhibited, under planting may be appropriate although dense canopy will inhibit its effectiveness. The planting areas are currently inundated with weeds spreading from the adjacent residential properties. Panic veldt grass, mirror bush, blackberry, valerian, cotoneaster, banana passionfruit, boneseed and sweet pittosporum are all growing within the planting areas. There is a large planting area along the track from Illawong Crescent down to the reserve which has been inadequately maintained. It would be ideal to encourage the residents in the adjacent properties to spend some time maintaining the weeds within this area so that TEN can spend time within the core areas of the reserve.
The planting areas have been fairly successful and it would be worth reviewing these to determine most successful species to continue rehabilitation.
4.3.2 Zone 2 – Ralphs Gully
Zone 2 is Council owned land.
Ralphs Gully extends from Hinsby Road to Hinsby Beach (Zone 3).
Ralph Chapman was the inaugural convenor of TEN. He initiated the work of TEN along the Taroona foreshore. Upon his death, TEN undertook a memorial planting in this unnamed gully linking into Hinsby Beach where Ralph used to walk regularly.
The geology is Ts on the creek bed, with the creek sides likely to be Qa overlain in many places by fill and sand sheet.
The gully is dominated by blue gums and also contains a large black gum Eucalyptus ovata on the upper section. The area is extremely disturbed and contains minimal native understorey. The southern bank has been largely rehabilitated. Weedy groundcovers have been removed and natives planted, however the northern bank remains dominated by weedy groundcovers (mostly garden escapees).
Weeds within the area include banana passionfruit, periwinkle, mirror bush, trailing daisy, panic veldtgrass, blackberry and canary broom.
- To promote blue gum habitat for the endangered swift parrot
- To reduce declared and environmental weeds to stop them from spreading into more significant areas.
Summary of Actions
This area remains relatively disturbed and due its close proximity to residential properties the chance of it returning to its natural state is relatively low.
The best approach to such an area is to undertake staged replacement of the garden escapees, removing the large mirror bush plants. Replacement plants should mainly include broad-leafed shrubs as the area is relatively closed and receives little sunlight. This should be followed by some understorey planting of grasses and other graminoids such as forest flaxlily Dianella tasmanica. Within the lower areas towards Hinsby Beach native ground covers have been planted. These areas should be encouraged through regular hand weeding, with the aim of spreading the groundcovers into adjacent areas.
4.3.3 Zone 3 – Hinsby Beach
Zone 3 is Crown land.
The Hinsby Beach zone includes a steep narrow strip of vegetation bounded by the beach and residential properties. The narrow strip joins with bushland from Illawong Reserve to the west.
The geology close to the bottom of the beach is Ts; the top is probably Qa. A lot of fill, beach sand and sand sheet obscures original structure.
The vegetation appears to have been mostly planted, however there are some mature blue gums and also some significant recruitment in the understorey from these blue gums. This regeneration of blue gums has most likely been occurring following the removal of several large macrocarpas.
- To encourage the regeneration of blue gums for the endangered swift parrot.
- To control all declared and environmental weeds
- To plant to increase diversity.
- To plant to stabilise the slope.
Summary of Actions
This area exists as a relatively thin strip of vegetation and consists mostly of planted species. It provides connectivity between Taroona Park and Illawong Reserve. The planted understorey on the slope requires maintenance and more planting in the future. Weeds include boneseed, mirror bush, red valerian, watsonia, briar rose, macrocarpa seedlings, cotoneaster and honeysuckle. Garden escapees are a problem, as are ongoing plantings of inappropriate species within the reserve area by neighbouring residents. The instability of the slope is a significant management and safety issue when working on this site. Attention should be paid to the use of bank stabilising species.
4.3.4 Zone 4 – Passionfruit Gully
Zone 4 is privately owned.
Passionfruit Gully receives its informal name from the extremely large infestation of banana passionfruit located on the southern bank of the gully, which once extended across the entire gully. This zone extends from Jenkins Street to the eastern end of Hinsby Beach (Zone 3).
The geology of the creek bed is recent shallow alluvial deposits resting on Ts. Both valley sides are cut into Qa but the southwest side has fill dumped extensively over it.
The northern bank has received regeneration works and has successfully been planted with native species. The area is privately owned, however TEN are given permission to work in the area on this significant weed problem, which is beyond the control of the residents. The area supports mature blue gum forest with a modified understorey.
- To promote blue gum habitat for the endangered swift parrot.
- To remove declared and environmental weeds to stop their spread into more significant areas.
This zone, like Zone 2, remains relatively disturbed due its close proximity to residential properties. The chance of it returning to its natural state is relatively low. The southern bank is entirely weed infested except for a small planted area to the east. It is recommended that works push west from this area slowly removing the weedy vines and woody weeds. As work progresses small areas should be planted and maintained before opening up new areas.
The weeds on this southern bank include banana passionfruit, cape ivy, nasturtium, blackberry, various grasses, cotoneaster, tree mallow and hemlock.
Several non-native plantings are also prominent and include gelder rose, European Ash, hawthorn and Australian sticky wattle. The latter should be monitored to ensure it does not spread to Zone 3.
A priority for works in this area should be to retain the northern creek bank as healthy bush, removing any weed infestation as and when required. At present the banana passionfruit, cape ivy and some woody weeds are slowly encroaching into the planted area. All vines should be removed from the canopy where they can be easily pulled. Plants can be treated at ground level by either hand removal or stem scraping. Woody weeds should be treated by cut and paste.
4.3.5 Zone 5 – Niree Parade Foreshore
Zone 5 is Council owned land.
This zone extends from northern end of Hinsby Beach (Zone 3) near Passionfruit Gully (Zone 4) through to Taroona Park. The southern part of zone 5 is very narrow as the residential properties extend to within 2m of the sand.
The geology is mostly Ts and is more permeable than some areas. It is affected by plenty of fill and an apron of beach deposits with pebbles under sand.
This area contains extensions of private gardens with some native grasses persisting on the foreshore and beachfront. The foreshore along Niree Parade exists as a thin strip of coastal vegetation behind Taroona Beach. There is an open space area extending to Zone 6 in the north western section which contains dune vegetation, mature blue gums and many blue gum and banksia seedlings. The planted area contains varying levels of success, with some areas clearly more established than others. Sweet valerian, spread from an adjacent residential property, has become a problem in the reserve at the southern end of Niree Parade.
It is evident that some of the grassy banks in the northern extent of the Niree Parade Foreshore and southern extent of Taroona Park now have improved recruitment of young blue gum saplings. It is surmised that this is due to the cessation of mowing these areas. Further modifications to mowing regimes under mature eucalypts to encourage further blue gum regeneration may be worthwhile to trial. This requires careful planning to ensure recreational access and views are maintained.
- To encourage the spread of foreshore vegetation up slope.
- To supplementary plant as necessary
- To be mindful of residents' view retention.
- To provide habitat for the endangered swift parrot.
- To maintain planted areas.
Summary of Actions
Zone 5 contains some remnant vegetation and also revegetated areas. The remnant foreshore vegetation should be encouraged to spread up slope, and supplementary planting should be undertaken in the areas where plantings haven’t been as successful. At all times the plants should be selected with people’s views in mind.
Maintenance of all planted areas is essential. Once again the regeneration of blue gums should be encouraged to provide habitat for the endangered swift parrot. Although this area is only a thin strip of mostly planted vegetation it is still significant as it provides connectivity between Taroona Park and Zone 3 which connects t0 Illawong Reserve.
Planting undertaken in 2000, along with self regenerating blue gum saplings below Ashtons Lookout, are affecting the view field. Selective removal of saplings may be necessary to retain ongoing views. Select tree retention can be appropriate as ultimately the trees grow above the view and the trunks can frame the outlook.
4.3.6 Zone 6 – Taroona Park
Zone 6 is Council owned land.
Taroona Park is bounded by the Tasmanian Aquaculture and Fisheries Institute (TAFI) to the east, the Taroona Bowling Club to the north, the Derwent to the south and Niree Parade to the west. (NB: Taroona Park in its entirety extends further north than this study area.)
The geology is little known as there is plenty of fill, sometimes groomed and imported soil. Some topsoil has also been removed. The western side is more permeable Ts under patchy Qa, especially clay top. The eastern side is impermeable Ts (where boulders outcrop on elevated areas). The low area behind the boat ramp may be raised beach or long extinct landslip heel. The generally impermeable soil and rock and the rapid removal of runoff will generally make it hard to establish anything other than trees and grasses in the core area.
This area contains some significant native vegetation including one threatened species listed as rare under the Tasmanian Threatened Species Protection Act 1995– the shade peppercress Lepidium pseudotasmanicum. This species is located at the bottom of Chiton Chase in the south west corner of Taroona Park.
The area is dominated by mature blue gum Eucalyptus globulus with occasional black gum E.ovata and white gum E.viminalis. Other species include blackwood Acacia melanoxylon, prickly box Bursaria spinosa, drooping sheoak Allocasuarina verticillata and native cherry Exocarpos cupressiformis. The area remains in relatively good condition in the core areas, with the main weed problems located along the top of the reserve. The Taroona Bowling Club and Skate Park located within the upper area of the park are diminishing the reserve values with weeds encroaching into the core bushland. The dumping of waste vegetation and grass clippings by these neighbours supplemented with runoff from irrigation of the greens is adversely affecting the reserve and exacerbating the weed threat.
The lower areas near to the foreshore are a managed parkland area containing a playground, picnic and toilet facilities. These areas also contain large mature blue gums which are known important swift parrot habitat.
A flight of steps has been constructed through the middle of the reserve connecting the skate park with the lower park facilities such as toilets. A network of smaller informal tracks traverses the neighbouring areas. These tracks are used by walkers and bikes. This issue is hard to address because if you block one area off then it is likely people are going to introduce even more tracks through the reserve. The track that runs parallel to the bowling green along the top of the reserve down to the bottom area should be formalised and upgraded. Other tracks should be closed utilising rocks or vegetation debris collected from within the reserve.
Target weed species include blackberry, sweet briar, boneseed, cotoneaster, banana passionfruit, canary broom and honeysuckle.
- To promote regeneration of blue gums for the endangered swift parrot.
- To encourage diversity within the core areas.
- To maintain the bushland as an important refuge for numerous species of wildlife, especially blue gums for swift parrots and white gums for forty-spotted pardalotes.
- To keep declared and environmental weeds out of the core bushland area.
- To explore ways to increase diversity of the understorey (eg controlled burn to encourage germination or deliberate planting).
The major aim of weed control within this area is to push the weeds back towards the boundaries and stop them from spreading into the core areas. This will involve initially working within the core areas treating all weeds and slowly pushing the weeds out. The use of fire may also be considered to encourage germination of some species and hence increase diversity.
Dialogue with the management of Taroona Bowling Club is necessary to outline some of the impacts of current management to the natural values of the reserve and to seek alternative solutions.
4.3.7 Zone 7 – Crayfish Point
Zone 7 is Crown Land.
Zone 7 extends from the southern boundary of TAFI at the eastern end of Taroona Park to the southern area of Zone 8 at the end of Nubeena Crescent. The foreshore walking track extends through the middle of this zone to Taroona Park. It shares its northern boundary with the Taroona Sewage Treatment Plant.
The geology is all reactive clay Ts with large boulders except for landslip which is almost entirely infill.
The area contains a narrow strip of remnant vegetation.
- To perform ongoing maintenance of the of the foreshore vegetation.
- To attend to the replacement of loss of mature gums and sheoaks as necessary.
- To maintain safe sightlines and views from the track.
Either side of the coastal track around the Crayfish Point headland is a strip of remnant vegetation in good condition, complemented with extensive plantings of local native trees, shrubs and groundcovers. At the southern end of Crayfish Point, just to the north of Batchelors Grave, the plantings have been so successful some judicious pruning may be required to maintain safe sight lines for walkers. The area is relatively weed-free with some scattered herbaceous weeds along the track.
The area contains numerous old trees which are suitable habitat for many species. Some assistance may be required with recruitment of these species as many are old and appear to be dying slowly. This may be undertaken with the use of plantings or possibly fire to encourage the germination of species such as Allocasuarina littoralis.
The area below Nubeena Crescent has been actively eroding since the stormwater diversion works were undertaken by the council in 2003. Since that time there has been a landslip and continual instability and the area has been fenced off. The areas now contain a dense weed infestation containing blackberry, fennel and boneseed. Access to this area is steep and possibly dangerous due to the unstable ground. This area needs to be examined by an engineer and suitable action should be taken to stabilise the area and make it accessible to treat the weeds. No work has been undertaken in this area since the landslip, and unfortunately the weeds are producing vast quantities of seed which has started to spread into adjacent areas.
Ice plant and other climbers could be planted along the fence line to screen the sewage works from the walking track.
4.3.8 Zone 8 - Nubeena Crescent to Melinga Place Foreshore
Zone 8 is Council Land.
Zone 8 extends north from the sewage treatment plant to the southern end of Melinga Place. This zone is a relatively thin strip behind residential properties along the foreshore. The zone broadens in the vicinity of the soccer field to include the eastern bank of the soccer field. The bushland within this area remains extremely disturbed and most native vegetation has been planted. There are some remnant patches along the waterfront, although these generally exist as isolated trees and shrubs. The area is bisected by a degraded track which runs above the high water mark. In one instance the track continues a short distance across a rocky beach.
The geology for most of this zone is Ts impermeable clay, such as that occurring in the south-west corner of the soccer ground cutting. Large amounts of fill surround the other sides of this ground. Some of the fill is extremely porous, making it difficult to establish plants. There is a small raised beach under the flat area below the soccer ground which acts as an aquifer and is responsible for the vigorous growth of the planted trees nearby. These trees were all planted in 2000. Interestingly, for the first four years there was very little growth, despite summer watering. After this time, those that found the aquifer have thrived. The bushland within this area remains extremely disturbed and most native vegetation has been planted. There are some remnant patches along the waterfront, although these generally exist as isolated trees and shrubs. The area is bisected by a degraded track which runs above the high water mark. In one instance the track continues a short distance across a rocky beach.
Notable weeds include: radiata pine, boneseed, blackberry, briar rose, cape ivy, fennel, red valerian, cotoneaster, mirror bush, canary broom and periwinkle.
- To maintain small remnant patches of native bushland and encourage their spread for wildlife habitat.
- Continue plantings to connect remnant patches to those in Zone 7.
- To successfully revegetate the banks of Kelvedon Oval.
There are numerous planting areas within this site, with varying degrees of success. The planted area at the end of Melinga Place was undertaken about 5 years ago following the removal of an extensive area of boneseed. This rehabilitation work has been extremely successful. The area has been mulched and maintained throughout the five years, with only scattered weeds existing within the plantings. Elsewhere along the foreshore the planting success has been variable. The presence of two mature radiata pines in this zone significantly inhibits the establishment of any other plants within their vicinity. Some areas also contain native ground covers such as ice plant Tetragonia implexicoma and saltbush Atriplex cinerea which have regenerated naturally.
Below the sports oval is an area dominated by a mature natural stand of blackwood Acacia melanoxylon. Its understorey is very disturbed with successful planting along the foreshore. The blackwood extends part of the way up the bank of the sports field. Apart from this stand of trees the bank is extremely eroded and contains a disturbed soil profile. Most planting attempts have been unsuccessful. The northern section of the bank contains a few remnant black gums Eucalyptus ovata and there are also some small native ‘islands’ at the base of the oval which have been planted with native hop bush Dodonaea viscosa, prickly mimosa Acacia verticillata and coast wattle Acacia longifolia var. sophorae. Below these 'islands' is a strip of well-established plantings which run parallel with the track just above high tide.