Greater Blue Mountains World Heritage Area Values Study in the Cessnock Local Government Area and Surrounds



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Threats and management


There are a number of threats that affect both the GBMWHA and the complementary lands that surround or are enclosed (i.e. inholdings) by the GBMWHA. Other threats solely affect either the GBMWHA or the complementary lands.

This section outlines the historical, immediate and possible future threats that affect both the GBMWHA and complementary lands. Additional threats associated solely with the complementary lands are discussed in Section 5.3.

An overview of the general threats faced within each of the three previously discussed and mapped regions within Cessnock LGA is outlined below.

      1. Key threatening processes


Key threatening processes are listed under Schedule 3 of the NSW Threatened Species Conservation Act 1995 and under the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999. A process is defined as a key threatening process if it threatens or may threaten the survival, abundance, or evolutionary development of a native species or ecological community. A process can be listed as a Key Threatening Process (KTP) if it could cause a native species or ecological community to become eligible for adding to a threatened list (other than conservation dependant), cause an already listed threatened species or community to become more endangered, or if it adversely affects two or more listed threatened species or ecological communities.

The KTPs considered likely to affect the GBMWHA and/or complementary lands are outlined in Appendix B.


      1. Regional overview

        1. Western Region


The western part of Cessnock LGA, containing Yengo National Park and Wollombi Valley and surrounds, is relatively isolated. This isolation has in part meant that in previous years the threats to complementary values in this area have been at relatively low levels.

The main use of this part of the Cessnock LGA is for either conservation purposes (Yengo National Park), agricultural purposes (private land) or forestry (State Forests). It is for this reason that a high level of biological integrity remains. While site-specific issues have been identified during the field inspections, generally the condition of remnant bushland in this area is high.

The main existing general threats to this area, apart from the more specific threats that are legislated such as Key Threatening Processes, consist of the following:

Mismanagement of the existing land uses, resulting in direct or indirect impacts upon Yengo National Park or the complementary values of other lands.

The potential for more intensive use of the agricultural lands for purposes such as rural – residential development.

The potential for mineral or gas exploration and extraction activities.

The management of existing land uses can be well understood and investigated in detail. Such land uses and their related threats are outlined in the following sections.

The potential use of the Wollombi Valley private lands for rural–residential development in the future is a general present and future threat. More intensive development of the valley could potentially lead to poorer management of the land than that which currently exists in the large agricultural holdings used for rural purposes.

The main mineral or gas exploration threat is likely to relate to potential exploration for gas. Such exploration is occurring at Broke (approximately 8km to the north west of the Cessnock LGA).

Some guidance in relation to the likelihood of future gas exploration is outlined in ‘The Lower Hunter over the next 20 years: A Discussion Paper’ (NSW Government 2013). This document outlines that core hole drilling and seismic surveys over the last five years indicate high potential for coal seam gas in the vicinity of the Wollombi – Grumps Retreat – Bucketty – Peats Ridge areas. NSW Government (2013) indicates it is possible that coal seam gas production could commence within the next two years, subject to coal seam gas exclusion zones, which were announced in February 2013, as well as appropriate environmental assessment.

An accurate likelihood of such exploration within western region is not known although any exploration/ extraction within this western region area would be expected to require strict controls in relation to potential impacts upon World Heritage values or complementary values.

        1. Central region


This part of the Cessnock LGA is subject to the highest level of land-use pressure (see Section 6). Many of these land uses result in key threatening processes that are described in detail in the next sections. Generally the threats within this part of the LGA relate to increasing intensity of land-use, such as increasing urban and rural–residential development.
        1. Eastern region


The eastern region is well vegetated and sparsely populated. To a certain degree, the existence of coal mines in this area has meant that other land uses and related threats have been restricted. In general, further clearing for mine expansions and increasing rural-residential development pose the main threats to complementary values within this part of the LGA.
      1. Discussion of key threats

        1. Climate change


Rapid climate change associated with human-induced emissions of greenhouse gasses is a potential threat to biodiversity values in the GBMWHA and surrounds.
          1. Threats


Rapid climate change has potential to impact biodiversity both directly and indirectly. Possible effects of climate change on biodiversity include:

alteration to water availability

changes in the intensity and frequency of fire

expansion in the distribution of species.


          1. Alteration to water availability


Climate change may result in a reduction or increase in rainfall that may affect biodiversity through changes to vegetation structure and composition. Reduced rainfall may result in the drying of wetlands, reduced flow in streams and rivers and increased vulnerability of rainforests to fire; possibly threatening the long-term persistence of these habitat types and the species which rely on them. Threatened species which could be affected include, but not limited to, the Giant Dragonfly, Blue Mountains Water Skink, Dwarf Mountain Pine, and Wollemi Pine. Increased water availability may result in changes to vegetation through increases in the abundance of mesic plants which could affect its suitability of habitat for a variety of species adapted to more open environments with greater light penetration, for example the Broad-headed Snake.
          1. Changes in the intensity and frequency of fire


Changes in temperature and altered rainfall patterns may result in changes to the intensity and frequency of bushfire. Increased temperature and reduced rainfall is likely to result in increases in the frequency and/or intensity of bushfires. The interaction between fire regimes and biodiversity is discussed further in Section 5.4.3.
          1. Expansion in the distribution of species


Changes to climatic conditions may result in the expansion of the distribution of both native and introduced species into previously climatically unsuitable habitats. These habitats are presently occupied by species, including endemic animals and plants, which are adapted to present cool environmental conditions. If conditions become suitable for common species with similar ecological niches to expand their distribution, existing species may experience greater competition for resources or predation. This could potentially result in the loss of cool climate adapted species in the long term. The interaction between potential weed expansion and biodiversity is discussed further in Section 5.7.
          1. Management


There is limited scope at the local scale to prevent human-induced climate change, however, its impacts may be mitigated by addressing other threats such as weed invasion, inappropriate fires regimes and disease which may affect the most susceptible species. Measures to address such impacts are addressed in throughout the remainder of Section 5 and in Section 7.
        1. Land clearing


Clearing of native vegetation is unlikely to occur on a significant scale within the GBMWHA, although may occur for reasons such as illegal firewood collection.

Legal clearing of substantial areas of native vegetation in the complementary lands is likely to be undertaken for:

agricultural activities in accordance with the Native Vegetation Act 2003 (NV Act)

construction of infrastructure, resource extraction (including mining and gas extraction) and industrial and urban development in accordance with the Environmental Planning and Assessment Act 1979 (EP&A Act).

Illegal clearing is likely to occur on a generally small scale within private agricultural and rural-residential properties throughout the complementary lands.

The NSW Scientific Committee indicates that land clearing is a major factor contributing to loss of biological diversity.


          1. Threats


The NSW Scientific Committee lists the following impacts/threats resulting from land clearing activities:

Destruction of habitat results in loss of local populations of individual species.



Fragmentation.

Expansion of dryland salinity.



Riparian zone degradation.

Increased greenhouse gas emissions.

Increased habitat for invasive species.

Loss of leaf litter layer.

Loss or disruption of ecological function.

Changes to soil biota.

Whether or not such clearing activities are legal or illegal, any clearing of native vegetation is likely to contribute to the above threats.

The main land clearing threats to the GBMWHA within Cessnock LGA are likely to result from agricultural clearing on rural lands that adjoin the boundary of the GBMWHA (including inholdings). A developing land clearing cause is considered to be related to mineral and/or gas exploration in areas like the Wollombi Valley. Impacts from such activities are yet to be realised. Further up the Hunter Valley clearing threats are more likely to be related to expansion of mining activities, combined with agricultural clearing activities. Mining clearing tends to be at a larger scale than agricultural clearing in the upper parts of the valley and can therefore have more far-reaching affects to the environments that adjoin the GBMWHA boundary.

In the areas of Cessnock LGA that are further from the GBMWHA, land clearing is more likely to be related to the increasing intensity of land use for residential, commercial, industrial or more intensive agricultural activities.

          1. Management


Effective management of land clearing activities is a complex issue that required detailed consideration. The most powerful ways to regulate land clearing are through:

detailed strategic planning processes that analyse appropriate land uses and zonings, and communication of this to land owners

effective communication at a land-owner level about values of remnant bushland and legislation that applies to land clearing activities.

It is recommended that when land use zoning is reviewed, in consultation with relevant stakeholders, any areas of important native vegetation are provided with appropriate legislative protection to regulate the impacts of vegetation clearing on biodiversity values.

Correspondence with land managers responsible for management of private agricultural and rural-residential land is recommended. Such correspondence should include details of rights and responsibilities under the NV Act and advice regarding biodiversity values and ecosystem services and how these can be preserved.

        1. Habitat modification


The following threats involve modification of habitat through changes in vegetation structure and composition and/or the loss of specific microhabitat features (e.g. tree hollows, exfoliating rock).

These threats may result in impacts on habitat for threatened species by reducing the foraging, sheltering and breeding opportunities and are described below.


          1. Bushrock removal


Substantial historic bushrock removal is likely to have occurred but is unlikely to continue in anything but a minor and localised basis within the GBMWHA. Bushrock removal may continue on a localised basis within the complementary lands, particularly in association with areas with vehicle access such as forestry trails. The animal groups most likely to be adversely affected by bushrock removal are reptiles and frogs including the threatened species such as the Broad-headed Snake and Red-crowned Toadlet.
          1. Forest eucalypt dieback


Forest eucalypt dieback associated with over-abundant psyllids and Bell Miners is one of a range of dieback scenarios in Australian eucalypt forests that are as yet poorly understood (Office of Environment and Heritage 2013). This form of dieback is characterised by leaf loss from the tips of twigs and branches, and can result in defoliation and if it persists may result in the death of trees over quite extensive areas. Affected trees exhibit lower reproductive success. Tree recruitment is often low and weed invasion extensive in affected stands.

The forest types in the study area most likely to be susceptible to dieback are those dominated by Sydney Blue Gum (Eucalyptus saligna), Flooded Gum (E. grandis), Grey Ironbark (E. siderophloia), Narrow-leaved White Mahogany (E. acmenoides), Grey Gum (E. punctata) and Grey Ironbark (E. paniculata). Communities dominated by these species typically occur in riparian areas and on shale-derived or volcanic soils and typically consist of tall moist to dry sclerophyll forests. Due to the significant changes in vegetation structure and biophysical conditions which may occur, a wide variety of animals and plants in these communities may be significantly affected.


          1. High frequency fire


Fire is a natural essential element required by many Australian sclerophyll vegetation communities. Fire plays a positive role creating conditions ideal for the establishment and success of many species including the release of nutrients from the soil and removing competitively dominant species to allow more light and rain to reach the surface. Post fire conditions stimulate the reproductive success of many plant species by promoting the germination of soil and aerial seed banks, resprouting of vegetative structures such as lignotubers and flowering (Hammill & Tasker 2010).

However, inappropriate fire regimes (i.e. intensity, season, type and frequency) can also be a threat to biodiversity. Specifically the intensity, season, type and frequency of fire have the potential to disrupt natural ecological processes such as life cycles, vegetation structure and composition (NSW National Parks & Wildlife Service 2009). Altering these ecological functions, through inappropriate fire regimes, may represent a threat to biodiversity within the GBMWHA and complementary lands. For instance burning more frequently than the regeneration period of some species, such as those that generate a seed bank, could lead to their elimination from the GBMWHA or lead to their extinction (Wollombi Valley Landcare Group Inc 2003).

Fire is a threat that must be managed to ensure the long term survival of native vegetation within the GBMWHA and complementary lands. Fire regimes are actively managed within the GBMWHA and NPWS estate and, possibly to a lesser extent, in State Forests and council reserves.

Potential threats that may result in increased fire frequency in the western region include accidental or purposeful fire ignition by private landholders within in-holdings or adjacent lands.

High levels of arson anecdotally occur within the central and eastern regions of Cessnock LGA and management of such issues can be difficult.

          1. Loss of Hollow-bearing trees


Substantial loss of hollow-bearing trees is likely to have occurred during historic timber harvesting activities in parts of the GBMWHA but is unlikely to continue in anything but a minor and localised basis. Substantial historic loss of hollow-bearing has occurred due to broad scale vegetation clearing, vegetation thinning and firewood collection within the complementary lands. Loss of hollow-bearing trees is continuing due to incremental clearing of remnant vegetation and the senescence of remnant paddock tress.

Loss of hollow-bearing trees reduces the availability of sheltering and/or breeding sites for a variety of arboreal mammals, birds, reptiles and frogs and hollow-dependent birds and bats.
          1. Loss or degradation of sites used for hill-topping by butterflies


The potential for loss or degradation of sites used for hill-topping by butterflies in the GBMWHA is low as minimal clearing or degradation of hill-top sites has occurred within the GBMWHA and existing protections against vegetation clearing are likely to be sufficient for the prevention of future impacts. In the complementary lands, however, there is a moderate potential for loss or degradation of hill-topping sites due to vegetation clearing and forestry operations in the ranges immediately to the east of the GBMWHA which are largely included in state forests.
          1. Removal of dead wood and dead trees


Substantial removal of dead wood and dead trees is likely to have occurred in areas within the GBMWHA previously subject to forestry. Removal is unlikely to continue in anything but a minor and localised basis involving collection of wood for use on camp fires associated with roadsides and camping grounds.

Substantial historic removal of dead wood and dead trees is likely to have occurred during the establishment of grazing properties (Photo 5.) and is likely to be continuing as a result of illegal firewood collection for personal use and sale, tidying up of farmland and incremental clearing of native vegetation on private property.

Removal of dead wood and dead trees is likely to affect a variety of animals including small arboreal mammals, hollow-dependent microbats, small terrestrial mammals, ground-foraging birds and reptiles.

Photo 5. Removal of dead wood for grazing purposes at Boree Track


          1. Management


Existing management of threats resulting in habitat modification are summarised in Table 5.. Recommendations for changes or additions to management regimes are provided in Section 7.

Many of these threatening processes are at their greatest intensity in private lands. The availability of resources, planning and expert advice for land owners has been identified as a constraint to the ecologically sustainable management of private lands in the Wollombi Valley (Wollombi Valley Landcare Group Inc 2003).

Government incentives such as the old ‘Free landowners Information Package’ have provided funding and technical advice to landowners to aid in the conservation of remnant vegetation on private properties.

Effective strategic zoning and legislation is also important to regulating habitat modification activities.

Table 5. Management of habitat modification threats

Threat

Existing management

Bushrock removal

Restrictions on vehicle access are likely to minimise the potential for illegal bushrock removal in the GBMWHA. Little information is available regarding illegal bushrock removal in the complementary lands.

Forest eucalypt dieback

Little information is available regarding the presence or absence of forest eucalypt dieback in the GBMWHA or complementary lands.

High frequency fire

A number of management and fire management plans have been prepared for particular areas within the GBMWHA containing details strategies fire management:

Watagans National Park and Jilliby State Conservation Area – Plan of management (NSW National Parks and Wildlife Service 2010).

Yengo National Park, Parr State Conservation Area and Finchley Aboriginal Area – Plan of management (NSW National Parks and Wildlife Service 2009).

Blue Mountains National Park – Plan of management (NSW National Parks and Wildlife Service 2001).

Blue Mountains National Park – Fire management strategy (NSW National Parks & Wildlife Service 2004).

Fire trails have been constructed in Wollombi valley to control bushfires and reduce bushfire hazard to Wollombi.



Loss of Hollow-bearing Trees

Due to prohibitions on vegetation clearing, loss of hollow-bearing trees is unlikely to be a significant issue in the GBMWHA.

Prescriptions for forestry operations require the retention of a proportion of hollow-bearing trees and young trees for long-term replacement of hollow-bearing trees. These measures mitigate the loss of hollow-bearing trees due to forestry but do not eliminate the process (NSW Scientific Committee 2007). The Private Native Forestry Code of Practice requires the retention and protection of a minimum number of hollow bearing trees per hectare dependant on the broad forest type (Department of Environment and Climate Change 2007b). The NSW National Parks and Wildlife Service has published an advisory note to assist voluntary conservation of natural tree hollows on private and public land (NSW National Parks and Wildlife Service 1999).



Loss or degradation of sites used for hill-topping by butterflies

Due to prohibitions on vegetation clearing, loss or degradation of sites used for hill-topping by butterflies is unlikely to be a significant issue in the GBMWHA. Little information was available on hill-topping sites or their management in the complementary lands, however there is a hill-topping site known at Mount Sugarloaf.

Removal of dead wood and dead trees

Due to prohibitions on vegetation clearing, removal of dead wood and dead trees is unlikely to be a significant issue in the GBMWHA. The NSW National Parks and Wildlife Service has published an advisory note to assist voluntary conservation of natural tree hollows, including dead standing trees, on private and public land (NSW National Parks and Wildlife Service 1999).


        1. Diseases


The three diseases caused by plant and animal pathogens of moderate and high relevance to the study area are described below.
          1. Plant pathogens threat

16.Exotic Rust Fungi of the order Uredinales (Myrtle Rust, Uredo rangelii)

Myrtle Rust (Uredo rangelii) is a fungal pathogen which affects plant species within the family Myrtaceae. A large proportion of the plant species within the GBMWHA are in the family Myrtaceae including species which are prominent components of and/or dominate many of the ecosystems of the area including the eucalypts, Leptospermum spp., Syzygium spp. and Melaleuca spp. This fungus was recently recorded for the first time in Australia on the Central Coast, NSW in April 2010 and has now been recorded from Shoalhaven NSW to the QLD border, generally occurring along the NSW coast (Department of Industry and Investment 2010a). This fungus is easily spread by wind, water insects, machinery, tools, vehicles and movement of infected plant material (Department of Industry and Investment 2010b, 2010c).

Myrtle Rust has been recorded within the GBMWHA it is highly likely that a large proportion of this area has potential to be infected by the fungus, due to the presence of susceptible species and fast rate of the current spread of the disease within NSW.

Introduction and establishment of Exotic Rust Fungi of the order Uredinales pathogenic on plants of the family Myrtaceae is currently listed as a Key Threatening Process under the TSC Act and the EPBC Act.

17.Root-rot Fungus (Phytophthora cinnamomi)

Root-rot Fungus or Cinnamon Fungus (Phytophthora cinnamomi) occurs as an epidemic within disturbed plant communities that contain species inherently susceptible to the pathogen. This pathogen causes die-back in plant species, reducing the availability of food and shelter resources for animal species (Natural Heritage Trust 2004b). The fungus affects a large number of native plant species from a variety of families. The fungus has been recorded within Western Australia, Victoria, Tasmania, South Australia and along the coast of Queensland in areas that receive a mean average rainfall of 600 mm. This fungus spreads independently through very moist but well aerated soil and more rapidly through the transport of soil during road construction, nursery trade and bushwalking (Environment Australia 2001).

Whilst Root-rot Fungus has not been recorded within NSW it is likely that areas within NSW (including the GBMWHA) would be susceptible to the fungus, due to presence of potentially susceptible species, favourable environmental conditions and current spread of the disease throughout the rest of Australia.

Infection of native plants and dieback and caused by the root rot fungus (Phytophthora cinnamomi) is currently listed as a Key Threatening Process under the TSC Act and EPBC Act.

          1. Animal pathogens threat

Amphibian Chytrid Fungus (Chytridiomycosis – Batrachochytrium dendrobatidis)


Chytridiomycosis is a worldwide highly infectious amphibian disease caused by the pathogen Batrachochytrium dendrobatidis. This disease is potentially fatal to all species of amphibian and all survivors are considered to be carriers of the disease (Natural Heritage Trust 2004a; Office of Environment and Heritage 2011). The fungus has been first recorded in Australia in 1978 in south-east Queensland (Office of Environment and Heritage 2011). The species has now been recorded from four regions of Australia – east coast, south-west Western Australia, Adelaide and central Kimberly (Department of Sustainability Environment Water Population and Communities 2009). Human-induced spread of the pathogen occurs through transportation of frogs, cross contamination as a result of handling infected specimens or the inadvertent transportation of infected material (e.g. wet mud or water) between frog habitats (Office of Environment and Heritage 2011).

Whilst the prevalence of Chytrid Fungus within the GBMWHA is largely unknown it is likely that the frog species within the GBMWHA would be susceptible. It is likely that apparent declines in some species of stream-dwelling frog in the GBMWHA (e.g. barred frogs, Mixophyes spp.) are attributable, at least in part, to Chytrid Fungus.

The infection of amphibians with Chytrid Fungus resulting in Chytridiomycosis is currently listed as a Key Threatening Process under the Threatened Species Conservation Act 1995 and the Environment Protection and Biodiversity Conservation Act 1999. This disease is threatening to affect all threatened species of amphibian within Australia.

          1. Management


Myrtle Rust, Root-rot Fungus and Amphibian Chytrid Fungus are established in the Sydney Basin Bioregion but are unlikely to have reached their maximum possible distribution. These pathogens have different ranges of natural dispersal mechanisms; however, all three can be spread by human activities. The natural dispersal mechanisms of these species include wind and water movement and animal foraging activities. There is limited potential to manage these natural mechanisms with the possible exception of the control of feral animals such as pigs which may be a vector for the spread of Root-rot Fungus and feral honeybees which may spread Myrtle Rust. Management of feral animals is discussed in Section 5.6.

Management of possible human spread of these pathogens should include a combination of strategies including:

education of the users of the GBMWHA and complementary lands regarding ways of minimising the potential for spread of pathogens

monitoring of likely entry points such as road and track edges to detect the presence of Myrtle Rust and Root-rot Fungus

signage and/or exclusion fencing of infected sites

treatment of any infestations of Myrtle Rust and Root-rot Fungus detected, if practicable.



        1. Pest animal species

          1. Threat


Pest species have been identified as a key threat to biodiversity within the study area. The impacts of pest animal species are likely to be most intense in areas of the GBMWHA that are subjected to edge effects generated from previous disturbance. Edge effects result in zones of changed environmental conditions which promote the growth of different vegetation types (including weeds), promote invasion of pest animal specialising in edge habitats or change the behaviour of resident animals (NSW National Parks & Wildlife Service 2009). These new environmental conditions can generate higher levels of predation by introduced mammalian and native avian predators.

The pest animal species that have been identified or are considered likely to be present within the GBMWHA, their distribution and potential impacts are described in Table 5.. The majority of these pest animal species are listed as a key threatening process listed under both or one of the TSC Act and the EPBC Act.

Table 5.2 Summary of pest animal distribution and potential disturbances in the GBMWHA and complementary lands

  1. Pest animal

  1. Distribution within GBMWHA

Identified disturbance

  1. Cats

  1. Likely to be most intense in complementary lands near rural properties and at GBMWHA boundaries but present throughout the study area.

  1. Predation on native fauna such as small mammals, birds and reptiles

  1. Foxes

  1. Likely to be most intense in complementary lands near rural properties and at GBMWHA boundaries but present throughout the study area.

  1. Predation on small to medium-sized native mammals, ground-nesting birds and reptiles.

  1. Wild dogs

  1. Likely to be most intense in complementary lands near rural properties and at GBMWHA boundaries but present throughout the study area.

  1. Predation on native fauna such as medium-sized to large native mammals and ground-dwelling birds.

  2. Loss of the integrity of remnant Dingo populations due to hybridisation

  1. Cattle and wild horses (feral and domestic strays)

  1. Localised distribution

  1. Disturbance (grazing and trampling) of native vegetation resulting in stream bank and waterhole erosion and prevention of regeneration of native vegetation.

  2. Dispersal of weed species.

  1. Rabbits

Likely to be most intense in complementary lands near rural properties and at GBMWHA boundaries.

Competition with native fauna for food and habitat resources.

Disturbance to the structure and composition of native vegetation and associated reduction in the suitability of habitat for native animals.

Dispersal of weed species.


  1. Pigs

  1. Localised distribution for example Mellong Creek – Wallaby Swamp and Wallabadah areas within Yengo Nation Park

  1. Disturbance (grazing for food and wallowing) to soil resulting in stream bank and waterhole erosion and preventing regeneration of previously cleared areas. Spread of weeds and plant pathogens (e.g. Root-rot Fungus.

  1. Deer

  1. Apparently localised distribution but not well known.

Disturbance (grazing and trampling) to native vegetation resulting in stream bank and waterhole erosion, prevention of the regeneration of previously vegetation and reduction in the suitability of habitat for native animals.

  1. Dispersal of weed species.

  1. Goats

Isolated small herds throughout GBMWHA

Competition with native fauna for food and habitat resources.

  1. Fish

  2. (e.g. Mosquito Fish & Carp)

Distribution unknown – likely in downstream areas from disturbed waterways and inholdings.

Predation on eggs and fry/tadpoles of native fish and frogs and on invertebrates.

Modification of in-stream vegetation (carp).

Generation of turbidity (carp).


  1. Feral honey bees

Distribution unknown

Competition with native bee species for tree hollows and floral resources.

Spread of Myrtle Rust.



  1. Yellow crazy ant

Unlikely – not known within the area

Predation on native fauna including invertebrates, birds, reptiles, amphibians and fish

Competition with native fauna for food and habitat resources.

Reduced seed production and increase mortality in some tree canopy species.


  1. Fire ant

Unlikely – not known within the area

Predation on native invertebrate and small vertebrate species.

Replacement of native invertebrate predatory species disrupting invertebrate food webs.

Disruption of native plant pollination and seed dispersal.


  1. Cane toads

Unlikely – not known within the area

Severe population decline of predatory native fauna.

Competition for food and habitat resources.



  1. Noisy Miners

Likely near edges of GBMWHA

Displacement of other native bird species

Source: (Office of Environment and Heritage 2013), (Department of Sustainability Environment Water Population and Communities 2013), (NSW National Parks and Wildlife Service 2009) and (Wollombi Valley Landcare Group Inc 2003).

Photo 5.2 shows understory removal due to cattle grazing and wild horses, the native canopy is still relatively intact, with understorey absent.





Photo 5. Understory disturbance due to cattle and horse grazing
          1. Management


Major programs of vertebrate pest control are undertaken in the GBMWHA in conjunction with neighbouring landholders (NSW National Parks and Wildlife Service 2001). Control programs involving co-operation by a various stakeholders are in place for pigs and dogs for the southern section of the GBMWHA (NSW National Parks and Wildlife Service 2001). Small scale control programs have been undertaken to target some other vertebrate pests such as goats, foxes, cats, rabbits in the past. These programs have involved targeting of problematic outbreaks rather than systematic control (NSW National Parks and Wildlife Service 2001).

As Foxes affect both biodiversity and agricultural values, fox control in cooperation with landowners and NSW National Parks to eradicate foxes from properties. Encouraging land owners to cover compost removes scraps etc. to get discourage the presence of foxes (Wollombi Valley Landcare Group Inc (2003).


        1. Weeds

          1. Threat


Eight Key Threatening Processes, related to weeds and relevant to the study area, are listed under the Threatened Species Conservation Act 1995 and the Environment Protection and Biodiversity Conservation Act 1999 (refer Appendix B.).
Although the majority of the GBMWHA is not subject to weed invasion, weeds have been identified as key a key threat. Specifically, weed invasions have been limited to areas that have been previously disturbed for development, mining and agriculture (including reserve boundaries and along access tracks) and locations downstream of these areas (NSW National Parks and Wildlife Service 2009). Increasing visitors to the GBMWHA threaten to increase the introduction, spread and dispersal of weeds both into the GBMWHA from complementary lands and from the GBMWHA to complementary lands (NSW National Parks & Wildlife Service 2009).

There are over 60 declared noxious weeds that are known to occur within the GBMWHA and hundreds of additional environmental weeds of concern that have the potential to invade (NSW National Parks & Wildlife Service 2009).

Extensive weed infestations attributable to stormwater runoff have been identified in the following areas of Blue Mountains National Park:

Gorse Ulex europaeus, upper Blue Mountains & Grose Valley, Popes Glen and Braeside Creek.

Lantana Lantana camara, lower Blue Mountains, Nepean River and Erskine Creek.

Privet Ligustrum lucidum, upper and lower Blue Mountains areas particularly south of the Great Western Highway.

Scotch broom Cytisus scoparius, upper Blue Mountains, Katoomba Creek.

Montbretia Crocosmia crocosmiiflora, upper Blue Mountains, creeklines and roadside verges (NSW National Parks and Wildlife Service 2001).

Monterey pines (Pinus radiata) have invaded in the Mt Werong-Banshea and Newnes Plateau areas where plantations are located adjacent to the GBMWHA boundary (NSW National Parks and Wildlife Service 2001).

In Yengo National Park and adjacent lands, invasive introduced species such as Blackberry Rubus fruticosus have colonised disturbed sites in and around the built up areas and adjoining rural properties and inholdings. Weeds spread by water, wind and/or by attachment to animals such as Noogoora Burr Xanthium occidentale, Dandelion Taraxacum officinale, Salix fragilis (Photo 5.3) and Weeping Willow Salix babylonica occur in some isolated localities downstream of disturbed catchments of the park. Watercourses, particularly Webbs Creek and the Macdonald River are sources of weed infestation as their headwaters are outside the park in rural areas dominated by introduced species of plants (NSW National Parks and Wildlife Service 2009).





Photo 5. Infestation of Salix fragilis along Stockyard Creek
          1. Management


Weed management programs in the Blue Mountains National Park have focussed on the control of specific occurrences of introduced plants such as Gorse and Lantana through the use of bush regeneration techniques. These programs have included volunteer groups and considerable scope exists for the expansion of use of volunteer groups, particularly in the control of weeds at the boundaries of the GBMWHA (NSW National Parks and Wildlife Service 2001).

At least three biological control agents have been released for the control of Scotch Broom (Cytisis scoparius) in the Blue Mountains region (NSW National Parks and Wildlife Service 2001).

A weed management strategy was prepared for the main valley of the Big Yango area in 2001 and provides strategies for control of introduced plants in this area (NSW National Parks and Wildlife Service 2009). Recommendations regarding management are provided in Section 7.

        1. Waterways

          1. Threats


Waterways within the GBMWHA and the complementary lands are subjected to various threats including:

erosion and sedimentation

pollution from stock, domestic use and irrigation

weed and pest invasion

decreases in water quality and quantity

modification of aquatic and riparian habitats (Department of Environment Climate Change and Water 2009; Wollombi Valley Landcare Group Inc 2003).

These threats are a direct result of human activities, such as vegetation clearing, mining and pumping water directly from waterways. Activities such as these are resulting in the modification of natural in stream and stream banks environments within the GBMWHA and in complementary lands.

The main threat to waterways within the GBMWHA include difficulties in maintaining water quality due to the location of headwaters outside of the park boundary, spread of weeds from upstream disturbed areas, and increased sedimentation as a result of land clearing and high fire frequency (NSW National Parks & Wildlife Service 2009). Photo 5. is an example of modification to waterways due to land clearing for farming purposes.



Photo 5. Waterway modification of Yengo Creek on Yengo Creek Road


          1. Management


The management of threats associated with waterways located within the GBMWHA and complementary lands is difficult as many are introduced from waterways located upstream. Threats such as pollution, vegetation clearing and introduction and spread of weed species have the potential to impact the rivers hydrology and habitats (NSW National Parks and Wildlife Service 2001).

Legislation, including the Sydney Catchment Management Act 2003 and National Parks and Wildlife Act 1974, provide a framework for managing the health of waterways by improving vegetation cover, water quality, ecological process and reducing erosion. This legislation is used by National Parks and Wildlife Service, Sydney Catchment Management Authority and other organisations to correctly manage the catchments within the GBMWHA and complementary lands (NSW National Parks and Wildlife Service 2001; Wollombi Valley Landcare Group Inc 2003).


The habitat types within the Wollombi Valley have been mapped to identify type, condition, threats associated with each vegetation type and the present conservation status (Fallding & Bell 1996). This habitat mapping has allowed the Wollombi Valley Landcare Group to run trial targeted programs to re-create habitat within sections of the William’s River and Stockyard Creek in the Wollombi Valley. Re-introduction of large woody debris and revegetation within these waterways is generating natural conditions that will provide habitat for many aquatic and riparian species and prevent stagnation (Wollombi Valley Landcare Group Inc 2003).

Plans of management and advisory notes have been developed and made available to private landowners and the broader community within the Wollombi Valley. These documents provide advice on how to manage threats such as erosion and sedimentation (Wollombi Valley Landcare Group Inc 2003).


        1. Illegal activities

          1. Threats


The GBMWHA provides a wide variety of natural resources, providing ecotourism, and environments for many recreational and illegal activities. It is predominantly the illegal activities (including illegal recreational activities) that are threatening the GBMWHA and complementary lands. The use of closed or management trails used for unregistered bike riding, four-wheel driving, car and rubbish dumping, theft of rocks and wildflowers, clearing for firewood and arson are all considered the main activities threatening the GBMWHA. Additionally, many recreational drivers illegally create new trails particularly in areas that are prone to erosion such as steep slopes (NSW National Parks & Wildlife Service 2009; Wollombi Valley Landcare Group Inc 2003).

Illegal activities are having detrimental impacts within the GBMWHA and complementary lands. Impacts associated with illegal activities include erosion, sedimentation, vegetation clearing and modification of habitat such as the removal of bush rocks which is threatening amphibians and reptiles including the decline in the Vulnerable EPBC Act-listed Broad-headed Snake (Hoplocephalus bungaroides) (NSW National Parks & Wildlife Service 2009).


          1. Management


The NPWS regulate visitor entry and monitor the activities of visitors to ensure that they do not impact the GBMWHA. This is a difficult task given the large size of the GBMWHA and limited resources available to cover the entire area.
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