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. Since then, Council’s flora and fauna surveys have been undertaken by Total Earth Care in 2006/2007, and Ecosure in 2015/2016 and 2019. In 2022, Ecosure undertook subsequent flora and fauna surveying of all sites serviced under Council’s bushland restoration contract including selected unmade road reserves. The results indicate 85% of these sites have increased their native vegetation cover and are either maintaining the current condition rating or have moved into the next highest condition rating since 2015, in accordance with performance targets set under the contract specifications.
Managing Bushland in Mosman
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.
From the table it is clear that each site has responded well to bushland restoration techniques and management strategies. A total 80.5% of bushland has progressed into the highest classification of native vegetation cover of 90+%. Some of the individual sites with significant improvement include Quakers Hat South, The Spit, Joels Reserve, Parriwi Point, Rosherville Reserve, Balmoral, Little Ashton, Sirius Park East and Reid Park.
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 weed species were 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.
Current and Future Management of Mosman Bushland Assets
Bushland Restoration Contracts
With the success of the current Bushland Restoration Contracts it was determined that the existing contract structure would be retained with minor changes, such as quarterly reporting requirements and progressive performance criteria and targets. This will ensure works continue to improve the native vegetation cover and Council is receiving value for money.
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 recent 2022 Flora and Fauna Survey Vegetation Cover Maps will be used as the benchmark (baseline data set) for the new bushland contracts and the specifications. The future performance will be compared against these to ensure contact site continue to improve.
In addition to the existing bushland areas covered under Council’s ongoing Bushland Restoration Contact, high valued Unmade Road sites have also been added to the relevant contract catchment areas to be proactively managed as part of this program. These sites include; Unmade Lennox Street, Unmade Upper Sverge Street, Unmade Musgrave Road Verge, Unmade Elfrida Street, Unmade Mosman Lane, Unmade McLeod Street (West), Unmade Burrawong Ave (North), Unmade Lower Sverge Street, Unmade Kallaroo Street, Unmade Morella Road (South), Unmade Fairfax Road (East), Unmade Grecia Lane (West), Unmade Hampden Street, Unmade Wallington Road, Unmade Kahibah Road (South), Unmade Edwards Bay Road, Unmade Warringah Road, Unmade Almora Street, Unmade Cobbittee Street, Unmade Grove Ave, Unmade Wolseley Road Verge, Unmade Quakers Road (Beauty Point Park), Unmade Bullecourt Avenue (North), Unmade Koowong Avenue (East) Unmade Glen Road, Unmade Inkerman Street (North), Unmade Inkerman Street (South), Unmade Moss Lane, Unmade Harston Avenue, Unmade Wyong Road, Unmade Killarney Street, Unmade Bay Street, Unmade Spit Road, Unmade Marsala Street, Unmade Government Road.
Maps – Distribution of Native Vegetation Cover for Contracted Bushland Sites
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 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. Of the 84 unmade road sites 35 high valued sites have been added to the Bushland Restoration Contracts with the remaining 49 managed on a priority based cyclical program and or Council’s Volunteer Bushcare Program.
Current Impacts on Bushland Areas
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 mindful 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 sustainability 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). However 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 propagate 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 available 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 Environmental Planning Policy (Biodiversity and Conservation) 2021 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 impact 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 place it in a bin.