Mosman is fortunate to enjoy a substantial amount of bushland within its boundaries, much of it being part of Sydney Harbour National Park. These large tracts of bushland at Middle Head, Georges Heights and Bradley’s Head are supplemented by a range of smaller bushland sites and unmade road sites that Council manages. Whilst generally small in comparison to the larger areas at Middle Head and Bradley’s Head these areas form an important part of the overall fabric of bushland in the local area and significantly add to the aesthetic value of the suburb.
The dominant vegetation community represented in Mosman’s bushland sites is a subclass of the Sydney Sandstone Gully Forest (SSGF 10ag) that being Regrowth SSGF. There are sites of Undisturbed Sydney Sandstone Gully Forest managed by Council and Parriwi Park found at the end of upper Spit Road the best example of this. The other main vegetation community type is Coastal Sandstone Heath (CSH 21ag) which is predominantly found at Bradley’s Bushland Reserve. This reserve is named after the Bradley Sisters who were early pioneers of bushland regeneration in Sydney and whos methods are still widely used today.
Council undertook a bushland management review in 2000 and it was resolved to undertake a flora and fauna survey to assist in setting priorities and determining specifications for future bushland management. This flora and fauna survey was conducted over the summer of 2000/2001 by Oculus. Council received the final report which was reported to Council on 12 June 2001.
When managing bushland Mosman Council ensures that weed management has clear conservation outcomes that follow three main principles:
- Retain relates to letting nature take its course and simply involves leaving healthy weed free bushland alone or if necessary applying minimal human intervention. Retain also relates to ensuring adequate fauna habitats are maintained and often the rate of weed removal in these situations will be dictated by the creation of suitable habitats in close proximity.
- Regenerate relates to using high level human intervention to help recreate natural processes in a bushland site and involves the removal and control of weeds in an area to assist the recolonisation of native plants. This is only possible in areas where native propagules are stored in the soil and therefore the site has resilience.
- Revegetate refers to the planting of locally sourced plant tubestock in areas where no regeneration of the bushland is possible. This is generally in areas that no longer have any natural soil profile and have either been heavily disturbed or have had fill placed on them and are usually devoid of any soil stored native propagules and therefore resilience.
The overall objective of bushland management in Mosman is to protect remnant vegetation or areas where natural resilience is found. Resilience refers to areas that have a natural soil profile and thus if correct intervention occurs the regeneration of remnant plant species should occur. By achieving this Council is protecting native fauna habitat and securing these areas for future generations and maximising our areas biodiversity.
The program also aims to expand remnant bushland areas by recreating vegetation communities found in the remnants through the introduction of fire, revegetation using locally sourced native tubestock and weed control. Another important objective of the program is to link these areas with similar areas to allow for wildlife corridors to reduce the impact of fragmentation on our native fauna populations. This is achieved through street tree planting and improving sections of road reserves that provide connectivity.
Council in 2001 implemented Bushland Restoration Contracts for the vast majority of its bushland sites. The Bushland Restoration Contracts started in October 2001 and were for a period of ten years. These contracts were introduced concurrently with the Community Environmental Contract (CEC) and were innovative in regard to duration, catchment based approach, and performance measurement criteria.
The contract sites fell into two catchments. The Port Jackson Catchment sites which contained seven sites of which all faced Sydney Harbour and the Middle Harbour Catchment sites which included eleven sites that all faced Middle Harbour. Five sites not included in the contract but identified in the Oculus 2001 report were Bradley’s Bushland Reserve, Rawson Park, Chinamans Beach Dunes, Little Ashton Park and an unnamed site found on the southern side of Rosherville Reserve. These areas were not included as Bradley’s Bushland Reserve was managed by the Friends of Bradley’s Bushland Reserve (FBBR) and the other areas were either not of high conservation value or managed by other means mainly by volunteers.
- Mosman bushland assets (467 kB)
A part of the review process and MOSPLAN objective was to replicate this study in five years time to assess the effectiveness of the program and scheduled works.
The 2006/2007 Flora and Fauna Survey was completed by the ecological consultancy company Total Earth Care (TEC). The field survey was conducted from September 2006 to April 2007 and included a comprehensive flora survey and a late Spring and early Autumn nocturnal and diurnal fauna survey. Fauna was also noted when surveying each site for vegetation. Fauna census data (recorded sightings and records from Taronga Zoo Wildlife Clinic, DECC Wildlife Atlas, Barry Lancaster) for the LGA from 2001 to 2006 was also utilised.
The flora and fauna survey showed that in the period from 2001 to 2006 there was an overall increase in the percentage of native vegetation cover across all of Mosman’s bushland sites that are actively managed under the ten year bushland restoration contract. Chinamans Beach Dunes was added to the Middle Harbour contract in 2003 as the dune vegetation was in good health but required constant maintenance for it to remain this way and adding it the contract was a cost effective way of doing so. The total area of bushland with greater than 90% native vegetation cover in 2006 after 5 years of the contracted bushland works was 45%. This was an increase of 20% from 2001 level and justified the bushland contract work.
In relation to weed cover over the same period there has been an overall reduction in the weed percentage classes at the vast majority of the bushland sites. The most significant reductions have been in areas of greatest resilience and this includes some areas previously assessed as in a high weed percentage cover that are now in a low category. This is significant as it shows that the contractors are targeting the right areas and are working from good bushland areas to bad. Also another significant positive finding in relation to weed cover was a large reduction in percentage cover of woody and vine weeds (plants that severely alter a natural ecosystem’s ability to regenerate).
In recognition of its successful bushland management program Council nominated for a Biodiversity Management Award through the Local Government and Shires Association of NSW Excellence in Environment Awards. These awards recognise initiatives in conserving and enhancing biodiversity on public and private land in urban and rural areas. This includes community involvement in protecting and conserving natural environments and wildlife habitat, rehabilitating and restoring degraded areas, and the improvement of wetlands management. Mosman Municipal Council was Highly Commended in Division B for its Bushland Management Program Flora and Fauna Survey 2006/2007.
Bushland Restoration Contract 2001-2011 Review
The Bushland Restoration Contracts 2001–2011 expired on 30 September 2011. Given the need to review the outcome of the existing contract performance and to have any new contract commence at the best time of year, an extension of the existing contract until April 2012 was sought and accepted by Council. It is considered prudent to start the new contracts at a time of year when vegetation and especially weed growth is slowing and mid-autumn is considered a good time to abate this effect. This start date would allow contractors time to become familiar with sites prior to the high vegetation growth period in the following spring.
Over the contract period 2001–2011 the bushland area under contract which has greater than 90% native vegetation cover has increased from less than 25% to 58%.
They have been successful with on-ground results exceeding targets, e.g. the 2010–11 MOSPLAN target for areas under contract having greater than 90% native vegetation cover (density) was 45%. The actual figure achieved was 58%. This is a significant increase from Council’s target and highlights the positive contribution the bushland contract work has had on our bushland sites. The ten-year contract has allowed a consistent work methodology and given the contractors a sense of ownership and pride in improving the biodiversity, health and long-term sustainability of these areas.
The result is particularly satisfying considering the difficult task of raising the native vegetation cover in areas where they have been historically modified and each site has a relatively large edge to area ratio. Basically the sites have been highly fragmented and are heavily exposed to external pressures from the urban environment. The work also demonstrates the benefits of creekline, seawall restoration and drainage works under the CEC.
Over the contract period 2001–2011 the bushland area under contract which has greater than 90% native vegetation cover has increased from less than 25% to 58%. The 2001 figure is an estimate as the contracted bushland sites were not mapped for native vegetation cover but for resilience and weed density. Therefore actual figures of area are not available and native vegetation cover for a site has been calculated from the weed density and resilience maps created from an initial flora and fauna survey in 2001.
This information is presented in Table 1. It also shows the percentage classification of native vegetation density for each site in 2006 and again in 2011, and reflects qualitative data for indigenous vegetation cover collected at all sites. This involved each bushland site being assessed by an ecologist and the same methodology of data collection was used in both 2006 and 2011. Each site was extensively surveyed in the field and native vegetation cover broken up into four categories (30%, 30–69%, 70–89% and 90+ %). This data was then mapped and totalled for each site and as a whole. For each site an average cover was determined.
From 2006 to 2011 the contracted bushland sites have an 18% reduction in areas of <30% native vegetation cover, a 17% reduction in 30–69% native vegetation cover, an increase of 12% of 70-89% native vegetation cover, and an increase of 12% of 90+% native vegetation cover.
|Bushland Site||% Classification of Indigenous Vegetation Cover|
|Quakers Hat South||30-69%||70-89%||70-89%|
|Quakers Hat North||30-69%||30-69%||30-69%|
|Quakers Hat Park||70-89%||90+%||90+%|
|Sirius Park East||30-69%||70-89%||70-89%|
|Sirius Park West||30-69%||30-69%||30-69%|
| *Percentage of Bushland with|
*Percentage of bushland with 90+% classification of native vegetation cover is a measurement determined by adding up individual areas of 90+% in each bushland site and totaling these and comparing against overall area managed by the bushland contracts.
For current distribution of native vegetation cover for each bushland site please refer to Maps – Distribution of Native Vegetation Cover for Contracted Bushland Sites.
It is clear that each site has responded well to bushland restoration techniques and management strategies. Sites such as Quakers Hat North, Lawry Plunkett and Sirius Park West, while still in the same overall classification of native vegetation cover of 30–69%, have also had significant improvement in the condition of bushland.
Further, for some sites where low levels of native vegetation cover remain it may have been determined through the sites’ Annual Work Plans to keep particular areas at low classification levels as the area may be providing suitable fauna habitat; was impractical to access safely; or erosion of the ground may occur if removed. Also on some sites resources may not have been available for primary clearance works as it may have been determined to leave and consolidate the better areas of the site as per the Bradley Method of bush regeneration.
Also some sites such as Harnett Park and Wyargine Bushland had minimal improvement in some areas due to factors not necessarily related to contractor works performance. For Harnett Park the dominance of Coral trees on the southern facing section of this site makes it extremely difficult to improve overall vegetation cover classification as these trees shade out native plant regeneration in summer and their leaf drop shades out native plant regeneration in winter and also adds unwanted nutrients to the soil. This section of Harnett Park will remain at a low level classification until resources can be found to address the Coral tree dominance. The presence of non-indigenous and mesic trees over many sites is consistently a hindrance in raising native vegetation cover.
For Wyargine Bushland it was resolved by Council that herbicide spraying could not take place. Therefore with the resources allocated to the site contract improvements to vegetation cover could not be made in all areas. A considerable amount of time was taken up by hand weeding when normal and best practice would involve the spraying of these areas with herbicides. This would have allowed greater coverage and more time at each visit for other bush restoration activities aimed at improving the site rather than limiting the spread of weeds from certain areas of the site. This issue is currently being addressed by dedicated Bushcare volunteers (supervised by Council’s Bushcare Officer) where their increased labour effort in certain areas is allowing the contractors to spend more time in other areas of the site and native plants can get established.
Bushland Restoration Contracts 2012-2022
With the success of the the Bushland Retoration Contracts 2001-2011 it was determined and decided by Council that the existing contract structure would be retained with monthly and annual reporting requirements but would include the reviews against identified progressive performance criteria and targets. This will ensure works are progressing and Council is getting value for money. While the current contract did have a 10 year performance measure it did not included progressive targets to achieve this 10 year objective. This will allow Council to exit the contract at one of the contract review periods if a contractor is not performing. The contract review periods are after year one, year four and year seven.
The approach adopted is to emphasize outcomes rather than prescriptive methodology or process. This can allow both the contractor and Council to implement the contract specification in a manner that is flexible and able to accommodate site difficulties and changes. The contract also allows Council to continue to implement a fire strategy over the sites to allow natural succession of the sites by stimulating the germination of native plant seed most likely stored in the soil of resilient bushland areas.
- The 2011 site specific Vegetation Classification Cover Condition Maps will be used as the benchmark (baseline data set) for the new contract and the specification is strongly linked to these maps. The future performance will be compared against these and each site’s condition map will be updated annually as part of the contract specification. The maps show each condition of vegetation cover within a site.
The tender document has also been modified and gives the tenderers two options to price:
Option A: Improve Indigenous Vegetation Cover to the next % condition level from the 2011 benchmark level for all sites.
Option B: Improve Indigenous Vegetation Cover to 90+% condition level for all sites.
The current bushland contract had an additional option of maintaining the sites at their current vegetation condition levels. This is considered not necessary as the sites are responding well to bush regeneration works and to let the sites sit in a stagnant state would, in the long-term, undo all the positive work that has occurred over the last ten years. Council should continue to be pro-active and drive positive change in our bushland sites.
Another proposed change to the existing contract is to break the contract into three catchments (contracts) instead of the existing two catchments. This would allow for greater pricing options and increased competition.
The current Port Jackson Catchment Contract sites include Morella Road, Clifton Gardens, Sirius Cove East, Sirius Cove West, Curraghbeena, Reid Park and Harnett Park. This will remain the same with the addition of Mosman Bay Creek. Mosman Bay Creek is an area where Council completed a major creekline restoration project late in 2010 through the CEC program. Council improved the creek’s functionality and significantly improved the area’s biodiversity value by removing noxious weeds and planting about a thousand indigenous native plants. This area has great potential and requires only minimal maintenance to progress it towards 90+% native vegetation cover.
The existing Middle Harbour Catchment Contract sites have been split down Military and Spit Roads forming a West and East Catchment. Middle Harbour West includes the addition of Joel’s Reserve with Quakers Hat South, Quakers Hat North, Quakers Hat Park and The Spit. Middle Harbour East includes Parriwi Park, Parriwi Point, Parriwi Lighthouse, Rosherville Reserve, Chinamans Beach Dunes, Wyargine Point, Lawry Plunkett Reserve and Balmoral.
- Map of bushland catchments (234 kB)
Maps – Distribution of Native Vegetation Cover for Contracted Bushland Sites
Based on the Tender Assessment Panel’s review and assessment against the weighted and non-weighted criteria for the Bushland Restoration Contract 2012-2022 it was concluded the following tenders were preferred for each catchment.
- Port Jackson – Waratah Eco Works;
- Middle Harbour East – Australian Bushland Restoration; and
- Middle Harbour West – Waratah Eco Works.
The tender also included schedule of rates pricing for a range of works associated with Bushland Restoration including Bushcare supervision, planting, erosion control works and difficult site access. Following the assessment of scoring of the tenders and pricing for additional works it is recommended that Waratah Eco Works, Australian Bushland Restoration and Australian Areas Management and Repair be identified as preferred tenderers for additional works. It is noted that Australian Bushland Restoration are the current provider of Bushcare supervision services. Continuity of volunteer supervisors is an important aspect in Bushcare. Schedule of rates pricing will apply as the need for change in site supervision arises.
For each site as per contract specifications Annual Work Plans were required to be produced and approved by Council staff to guide the contractor for the following years work. The plans are simple but note the works and methodologies required to met the contract specifications.
The bushland restoration contracts 2012-2022 for the Port Jackson, Middle Harbour East and Middle Harbour West catchments began on 1 June 2012 and ended their first year on 1 June 2013. Given the time required to achieve biodiversity outcomes and the beneficial outcomes of the previous 10 year contract, the current contract is again for 10 years with review options at the end of year 1, year 4 and year 7.
The areas under contract range from high quality bushland with little disturbance or impacts (e.g. Parriwi Park) to highly disturbed bushland remnants that have a high edge to area ratio and as a result are under constant pressure (e.g. Sirius Park East).
The sites that are managed under each catchment are shown in the table below.
|Port Jackson Catchment||Middle Harbour East Catchment||Middle Harbour West Catchment|
|Harnett Park||Balmoral||Joels Reserve|
|Reid Park||Lawry Plunkett Reserve||Quakers Hat South|
|Mosman Bay Creek||Wyargine Point||Quakers Hat North|
|Curraghbeena||Rosherville||Quakers Hat Park|
|Sirius Park West||Chinamans Beach Dunes||The Spit|
|Sirius Park East||Parriwi Lighthouse|
|Morella Road||Parriwi Point|| |
|Clifton Gardens||Parriwi Park|| |
The contract’s specifications are designed to preserve and enhance the biodiversity of Mosman Bushland through regeneration resilient bushland areas, revegetating non-resilient bushland areas and retaining areas that either offer good habitat for native fauna or is undisturbed remnant vegetation. The following principles are utilised to achieve this:
- Control of environmental ‘stressors’ (i.e. uncontrolled stormwater)
- Removal or control of the effects or impacts of the stressors (i.e. weed colonisation)
- Encouraging regeneration through natural process (i.e. seed production, dispersal and germination)
- Establishment and stabilisation of the restored area.
Contract Review and Performance Audits
The first year performance audit of the 2012-2022 contracts included detailed site inspections and formal audits of completed works for each contracted bushland site by Council’s Biodiversity Coordinator. Audit sheets were accompanied with native vegetation cover maps completed in May 2011, as well as the contract specification and the annual work plan as provided by the contractor at start of contract year. Each contractor is required to provide annual work plans for each site and at the end of each contract year an annual work report is to be submitted. They also provide with their invoice monthly work reports for each site visited during each month. All reports list works undertaken showing location and actual works performed and proposed works for the coming month.
The results of the first year audit would indicate that the contractors are meeting the contract specification and the environmental quality of the bushland areas is increasing. A summary of the findings of the audit results includes:
- There are very little noxious weed vines in the canopy of all contracted bushland sites. Where it is present it has been left for habitat or other areas of the site have been prioritised as per annual work plan. An example of this is Joels Reserve;
- >90+% indigenous native vegetation cover areas across all sites are meeting the contract specification. This is significant considering the recent weather conditions have been ideal for weed growth. Some areas that did have some vine weed in the shrub layer were Balmoral, Sirius Park East and Quakers Hat Park. In these sites it was obvious that significant work had occurred in other areas of the site. Progress in controlling shrub layer vine weed will be closely monitored during the next few months;
- All sites have native plant regeneration where it is possible and the native vegetation is establishing well. The weather has been very good for native plant growth;
- All revegetation sites are progressing well in locations as per annual work plans;
- All walking tracks and drainage lines are clear of vegetation and provide an uninterrupted path for people and stormwater respectively;
- All the sites are neat and tidy and provide good visual amenity;
- It is evident that all sites are progressing well and that the contract specifications are on the whole being met;
- Both contractors are following work plans for each site and all required paperwork has been submitted to Council; and
- Compliance has been achieved throughout the contract year in regards to Work Health and Safety of the contractors and the public.
Overall it is considered the contractors are meeting the specifications of the contract and all sites continue to progress toward improved condition and the biodiversity value. A Council resolution was passed on the 7 May 2013 extending the contracts for a further 3 until the 1 June 2016.
Mosman has 101 sections of unmade (unformed) road. Unmade roads are those small (some are actually quite large) parcels of land that are classified as public roads but are not accessible to cars and are actually areas of soft landscape. Seventeen of these sites are already maintained as open space under the Parks and Gardens Management Contract. The remaining 84 unmade roads were identified by the Flora and Fauna Survey 2001 and Council staff as having significant value to the biodiversity of Mosman, acting as habitat corridors by providing fauna with safe travelling paths. Thirty six of these 84 unmade road sections are maintained under the Bushland Restoration Contracts (as they directly join a larger contracted bushland site) or the Volunteer Bushcare program.
Council has also been able to work on a further 24 unmade road sites guided by the Unmade Roads Restoration Strategy adopted by Council on 18 June 2002. Through this program Council is currently actively managing all of the unmade road sites identified as having high and medium conservation values as defined by the Oculus Flora and Fauna Survey in 2001. This work is providing sustainable habitat corridors for our native wildlife and again improving the biodiversity of Mosman.
Adding to the unmade road areas Council also actively manages five road verges. Although these areas were not identified or assessed under the flora and fauna survys Council staff have identified the conservation significance or habitat corridor value of these areas. The linear strip of land on the lower half of Mugrave Street which divides the road into and upper and lower section is a great example of a road verge managed by Council for biodiversity conservation.
The fragmented nature of the total bushland area, and the position and shape of individual sites mean that most bushland sites in Mosman have a high edge to area ratio. This means they are greatly exposed to disturbances and impacts of urbanisation which can lead to the progress of increasing native vegetation cover slower than what would be liked.
Although Council is investing a significant amount of funds to restore bushland sites and progress has been high there are several issues Council needs to be mind-full of in the management of bushland areas in Mosman. Stormwater, encroachments, dumping of vegetation matter, tree and vegetation vandalism, feral animals and uncontrolled domestic animals all affect the quality and sustainabilty of the bushland in Mosman and reduce the positive effect of bushland restoration work carried out by Council contractors.
Most of the bushland areas are still suffering from stormwater impacts both from public and private lands, although the size of the public impacts have decreased significantly due to the completion of projects such as the Lawry Plunkett Integrated Stormwater Management Project, Balmoral Oval Contamination Capping and Creek Works and Beauty Point Stormwater Containment Project through Council’s Community Environmental Contract (CEC) the effects of private stormwaters are still an ongoing concern.
Uncontrolled (uncontained) stormwater runoff alters the distribution and abundance of water drainage in bushland areas which in turns leads to erosion, nutrification and water logging of bushland soils exposed to stormwater runoff. Stormwater also brings in weed propagules and the stormwater lines are often the first areas exposed to weed colonisation and from here weeds propogate and spread. Aside from bushland areas that are found deep within undisturbed bushland areas there would not be a creek/ stormwater line within Sydney that it not threatened by weed invasion or are completely colonised by weed species. It only takes a stormwater line from one property to cause erosion to Council bushland walking tracks, to nutrify the soil so native plant establishment is not likely however weed establishment is very likely and cause dieback in native shrubs and trees.
Long standing encroachments from private residences are still evident in Mosman bushland sites. Although these are identified as having a significant impact on biodiversity and will eventually be revegetated with locally sourced native tubestock, they are currently not high on the priority list for bushland restoration. Council will certainly not allow any new encroachments but the fact that many of the existing encroachments are grassed and maintained (and therefore they reduce weed spread and absorb water that would otherwise drain into the bushland) Council would prefer to spend its time and resources managing our good bushland areas and ensuring their long term survival. Again when resources are avialble and all other areas of bushland are stable these encroachments will be revegetated and returned back into bushland.
The dumping of vegetation matter into bushland areas is illegal. Garden waste and grass clippings cause long term damage to bushland by introducing weed seed and nutrients that alter the soil condition favouring the spread of weeds. Council Bushland sites are protected under State Environment Protection Policy No. 19 (SEPP 19) and under Section 629 of the Local Government Act. Anyone caught damaging bushland faces fines of no less than $2,200.00.
Feral and domestic animals are also negatively impacting on the biodiversity of Mosman’s bushland sites. Feral rabbits, even though they are controlled annually, are eating fresh tips of both planted and regenerating native plants. Domestic animals such as cats and dogs are responsible for the direct predation on possums and other native fauna. Dog poo also contributes to the nutrification of the soil and the trampling of vegetation by an uncontrolled dog is another negative imapct on the bushland. The community needs to be aware of this and take proactive steps to prevent their pets killing native wildlife and altering the bushland soils and vegetation. If your dog poos in the bush bag it and take the bag and place it in the bin.