Biodiversity Assessment Technical Report


Review of disturbances and their implications for fauna in the Central Highlands



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6.4 Review of disturbances and their implications for fauna in the Central Highlands

The decline of species can be largely attributed to the impacts of disturbances, both directly on species and indirectly, on essential components of their habitat. Disturbances which have negative effects (direct or indirect) on a species are referred to as threatening processes.



6.4.1 Methods


A review of the current state of knowledge of forest species and threatening processes was conducted to provide information to assist in setting priorities for future management, research and surveys. The review covers priority forest dwelling species (Table 6.1) in the Central Highlands, and was based on existing scientific literature and expert opinion.
For each species, the likely effects of each threatening process was documented, and a score assigned according to whether the threat was unknown, insignificant, minor, moderate or major for each species (see explanation below). A source was recorded for all information. These large primary data tables are not reproduced in this report.
The assessment of threatening processes was made in the following context:


  • Application of the ratings is for the Central Highlands only.




  • The ratings are assigned assuming no management actions are in place




  • Threatening processes which potentially affect more than one component of a species life-cycle or habitat scored a higher rating than another threat which affects fewer life-cycle or habitat components.

A range of mechanisms has been implemented or planned to address threatening processes which affect individual species in the Central Highlands. These include:



  • an extensive conservation reserve system covering a range of habitats on public land;

  • specific protection afforded by threatened species strategies in the Proposed Central Highlands Forest Management Plan;

  • requirements under the Flora and Fauna Guarantee Act 1988 and the Endangered Species Protection Act 1992; and

  • a range of provisions in the Code of Forest Practices for Timber Production and the Code of Fire Practices which address a number of the threatening processes operating in the region.

Other threatening processes on private land are addressed under the provisions of the Planning and Environment Act 1987 and the Catchment and Land Protection Act 1994. These are referred to in the assessment below, where relevant.

Threatening processes were scored for each species as follows:

- Effect unknown; no information available on the effect of the process on the species;

0 Processes not likely to be operating as a threat or there is no information to suggest that it is a threat;

1 Process is a minor threat, which by itself is unlikely to lead to broad scale decline of the species;

2 Process is a moderate threat, which is likely to lead to some decline of the species, especially if it operates in combination with other threatening processes; and

3 Process is a major threat, which if not checked poses a significant risk to the viability of the species in the Central Highlands.

6.4.2 Results and discussion


The combined score for each threatening process provides an indication of the relative importance of different threatening processes affecting fauna in the Central Highlands. In a number of cases, species are only known from the study area by a small number of records in the Atlas of Victorian Wildlife, and threatening processes were ranked by experts on the often limited knowledge of the species from other areas. For species whose occurrence and habitat is marginal within the Central Highlands, threatening processes which may be significant in other areas of the range but not within the Central Highlands, did not receive high rankings. Table 6.4 provides a summary of threatening processes for threatened forest fauna in the Central Highlands. Overall, unplanned fire was the highest scoring threat, followed by timber harvesting and introduced species. Timber harvesting was identified as a major threat to the greatest number of species. Overall, non-forestry clearing affected the greatest number of species, followed by timber harvesting and unplanned fire.

Table 6.4: summary of impacts of threatening processes on priority fauna species

Notes: (a)The ratings provided in this table assume no management arrangements in place to address threatening processes; (b) the ratings are relevant to the Central Highlands region only.

In this context, considerable resources are committed to the prevention and suppression of unplanned fires and a key element of forest management in the region is the development and implementation of threatened species strategies and detailed provisions to mitigate the effects of threatening processes operating in forests.


An explanation of each threatening process follows, with a discussion of the key species affected in the Central Highlands and the current or proposed management actions taken to mitigate the effects of each threatening process.

Fire (planned)

This category includes the effects of fire prevention activities such as fuel reduction burning within forested areas and ploughing, slashing and burning along roadsides, as well as the effects of regeneration burning following timber harvesting. Fuel reduction burns are largely carried out in foothill mixed species forests in the Central Highlands (LCC 1991a), not in wet forests and alpine areas. Within the Central Highlands, planned fire is recognised as a threat to 21 species; it was classified as a moderate threat to six species and a minor threat to 15 species. It is not considered a threat to three species, and its impact is unknown for nine species (Table 6.4).
The effects of fire on fauna vary depending on the fire regime, including the frequency, intensity and season of burns (Wilson 1994). Inappropriate burning regimes, such as too frequent or too infrequent burning, can alter vegetation floristics and structure and may affect the habitat suitability for some species of fauna. The response of species to fire depends on their habitat and food requirements. Some fauna species may be specially adapted to certain successional stages of vegetation. Particular fire regimes may create unsuitable successional vegetation stages. The Smoky Mouse appears reliant on understorey vegetation components strongly influenced by the frequency and intensity of fires (Menkhorst 1995). An inappropriate fire regime is a moderate threat to the Smoky Mouse in the Central Highlands. However, there is a lack of information on the ecological requirements of this species, particularly in relation to fire (Lee 1995). Planned fire can also result in the loss of habitat components such as den sites for Spot-tailed Quolls (C. Belcher pers. comm.) and may represent a threat if it occurs near, and subsequently spreads into, fire-sensitive habitat.
Planned fire is classified as a moderate threat to the Alpine Bog Skink and Spotted Tree Frog. The Alpine Bog Skink occurs in subalpine to alpine heathlands, areas which are not subjected to fuel reduction burning. However, a number of records of the species are close to areas where fuel reduction burning may be undertaken (P. Robertson pers. comm.). Although the species may be more widespread than current records indicate, its distribution is disjunct and populations may be lost if a fuel reduction burn spreads into suitable habitat.
Fire management in the Central Highlands is guided by the Code of Practice for Fire Management on Public Land (CNR 1995d), which outlines general principles and guidelines for fuel reduction burning, and Regional Fire Protection Plans (Dandenong Region, Central Gippsland Region and draft Alexandra Region Fire Protection Plans). Each fire protection plan includes a fuel management strategy, based on five zones. Fuel-reduction burns are undertaken in three of the strategically located zones to maintain fuel at defined levels. Areas containing significant biological, cultural or economic values which can be damaged by fire are generally located in Zone 5 in which prescribed burning is excluded, or Zone 4 where the ecological requirements of an area are given priority. Before fuel reduction burning is undertaken on Public land, each burn must be the subject of an approved burn plan in accordance with the Code of Practice for Fire Management on Public Land and regional fire protection plan. This plan details ecological issues including the known or likely presence of rare or threatened fauna in or near the area to be burned, and particular habitats needing protection. Such plans must take into account prescriptions developed for the protection of threatened species (CNR 1995a). Action statements include fire management prescriptions for species which are threatened by this process. However, for the majority of species, the effect of fuel reduction burning is unknown. Monitoring of populations is required to determine the effectiveness of prescriptions which are often developed with a limited knowledge of a species’ ecology, the habitat effects of the process, and the impact on populations. The Proposed Central Highlands Forest Management Plan (NRE 1996b) provides for a review of fuel reduction burn operations in areas containing fire sensitive biological values when the Regional Fire Protection Plans are revised.
Fuel reduction burning is known to have been undertaken within the catchments of several known sites of the Spotted Tree Frog. While the effects of this activity are still unclear, it may result in changes to vegetation adjacent to streams which could potentially affect populations (G. Gillespie pers. comm., Robertson in prep.). In addition, the effect of too frequent fuel reduction burns in catchments upstream from Spotted Tree Frog habitat may cause changes to the water quality of streams which may detrimentally affect breeding (Robertson in prep.). Although recognised as a potential threat, the effect of burning practices on the species is unknown (Watson et al. 1991, P. Robertson in prep, G. Gillespie pers. comm.). It is not known how far Spotted Tree Frogs move away from streams into the adjacent forest - this information is required for maintaining appropriate fire management prescriptions (P. Robertson pers. comm.). Until this critical habitat zone adjacent to streams is known, a 300m Special Protection Zone buffer on both sides of streams has been proposed for confirmed and potential frog locations within State forests of the Central Highlands region (NRE 1996b).
Fire prevention techniques used in remnants of native vegetation along roadsides include bulldozing and grading, slashing, ploughing, grazing and burning. These activities may result in the degradation and loss of habitat of species reliant on roadside remnants. Such species include Squirrel Gliders and Grey-crowned Babblers (Davidson and Robinson 1992, Adam and Robinson 1996, J. Alexander pers. comm.). Too frequent burning can limit the regeneration of tree species and thereby limit habitat suitability in the long-term for species such as the Squirrel Glider which require tree hollows for nesting and roosting. Such activities are a moderate threat to the Squirrel Glider within the Central Highlands (J. Alexander pers. comm.). The Central Highlands is the southerly extension of the known range of the Squirrel Glider; there is very little suitable habitat within the region and it has only been recorded from one locality (Atlas of Victorian Wildlife). The current status of the species is unknown in this region.
High intensity burning of the debris left following timber harvesting is a management practice used to remove fuel, reduce fire hazards, and is the preferred technique for seedbed preparation in the Central Highlands Ash forests (Jeremiah and Roob 1992). Of the trees retained on coupes as wildlife habitat, dead trees (stags) generally collapse following regeneration burns, and live trees, particularly ash-eucalypts (Alpine and Mountain Ash and Shining Gum), are often killed (Jeremiah and Roob 1992). Although still able to provide habitat for hollow-dependent fauna, dead trees are more susceptible to collapse due to windthrow and are unlikely to provide habitat for the length of the rotation (Lindenmayer et al. 1990, Macfarlane and Seebeck 1991, Milledge et al. 1991). This process is identified as a moderate threat to Leadbeater’s Possum and a minor threat to the Sooty Owl. Current Leadbeater’s Possum management strategies address the loss of retained hollow-bearing trees during regeneration burns. In accordance with the Action Statement (Macfarlane and Seebeck 1991; Macfarlane et al. 1995) protective measures used to aid the continuing survival of trees retained on logging coupes include using fire retardants and the provision of fuel breaks around such trees. Furthermore, strategically retaining groups of trees adjacent to buffer strips, or on the margin of coupes where there is adjoining forest, are practices employed to aid continuing survival of trees retained on coupes. The survival of retained trees and their subsequent use by wildlife requires monitoring to assess how effective this management technique is at providing wildlife habitat, and over what time period. Other management strategies pertaining to the conservation of Leadbeater’s Possum are outlined in the following timber harvesting sub-section.
Fire (unplanned)

Wildfire is an integral part of the ecology of forests, however wildfire can have a significant effect on vegetation and the distribution and abundance of fauna. The frequency and intensity of wildfire strongly influences the floristics of the understorey as well as the structure and age composition of the overstorey (Ashton 1981). The wildfires of 1939 burnt large areas of Mountain Ash forest within the Central Highlands, and in areas where the fire was most intense, stands of even-aged forest regenerated in place of old-growth forest (LCC 1991). The steepness and heavily forested nature of some of the Central Highlands makes it highly vulnerable to wildfire (CNR and AHC 1994). Fire can cause direct mortalities of animals, and may eliminate critical habitat components and entire populations. Mortalities may also result from food shortages and predation following fire (Wilson 1994). Species occurring in small, disjunct populations, or species with narrow habitat requirements, are particularly vulnerable to wildfire.
In the Central Highlands, severe wildfire is considered a major threat to Leadbeater’s Possum, Swamp Antechinus, Helmeted Honeyeater, Alpine Bog Skink and Baw Baw Frog. The 1983 Ash Wednesday wildfires are thought to have caused extinction of local populations of the Helmeted Honeyeater (Menkhorst and Middleton 1991, Menkhorst 1992, McCarthy 1996). The Swamp Antechinus is only known to occur in one State park within the Central Highlands; a wildfire in this park could result in elimination of the species from the region. Although wildfire is uncommon on the Baw Baw Plateau (DCE 1992a), the current low numbers of the Baw Baw Frog means that wildfire is a major threat, as it has the potential to affect the entire population. During the summer and autumn, adult Baw Baw Frogs are known to shelter amongst vegetation and litter in snow-gum woodland and montane wet forest; fires at this time are likely to have the greatest impact on the species (Hollis 1996). Wildfire is also considered a moderate threat to nine priority species and a minor threat to ten of the priority species. (Table 6.4).
The Department of Natural Resources & Environment has the responsibility for prevention and suppression of fire in State Forest, National Park, and all protected public land. The Code of Practice for Fire Management on Public Land (CNR 1995d) and regional fire protection plans include strategies for fire prevention, preparedness, fire suppression and recovery after wildfire. As described above, regional fire protection plans include a fuel management strategy incorporating a zoning system for fuel management. The fuel management strategy aims to reduce the rate of wildfire spread and improve the prospects for controlling wildfire close to assets and in strategically located regional corridors. The fuel management strategy zoning gives consideration to the natural values (including fauna values) and principles of environmental care. Similarly, fire suppression follows consideration of factors including values at risk from the wildfire or suppression activities.

Timber harvesting

This category includes the potential effects of timber harvesting, excluding associated activities such as regeneration burning and road construction and use. Some 36% of the forested public land in the Central Highlands is suitable and available for timber harvesting.
In the Central Highlands, timber harvesting is considered a major threat to Leadbeater’s Possum, Spot-tailed Quoll, Powerful Owl, Sooty Owl, Spotted Tree Frog and Baw Baw Frog, a moderate threat to Large-footed Myotis, Giant Burrowing Frog, Grey Goshawk and Masked Owl, and a minor threat to 14 of the priority species (Table 6.4 ). A detailed discussion of Leadbeater’s Possum is provided in box 2, below.
Box 2 Profile of an endangered species: Leadbeater’s Possum
A small possum endemic to the Central Highlands of Victoria, Leadbeater's Possum is classified as Endangered (CNR 1995a, ANZECC 1991). It is currently found mainly in mountain forests dominated by Mountain Ash, Alpine Ash and Shining Gum and has recently been recorded in Snow Gum woodland at Lake Mountain (Jelinek et. al. 1995). A small population also exists in Yellingbo State Nature Reserve, in lowland swamp forest. The habitat requirements of the species are primarily determined by:

  • nest-tree abundance and distribution

  • food availability, particularly wattle in the understorey

  • vegetation structure which allows the possum to move freely through the forest in search of food.

The 1939 fires burnt approximately 84% of the Central Highlands ash-eucalypt forests. Young regeneration resulting from these fires, or uneven-aged ash-eucalypt forest, that contains wattles and an ample supply of hollow-bearing trees is ideally suited for the species. The fire-killed remnants of mature forest and resultant regrowth from the 1939 fires has provided abundant feeding and nesting habitat during the past 30 years. However, as the fire-killed nest trees decay and fall, the extent of this type of habitat is diminishing. Loss of further potential nest trees in Leadbeater’s Possum habitat due to timber harvesting would further reduce the ability of the species to survive.


Available information indicates that preferred nest trees are collapsing naturally at an average annual rate of more than 3.6% which will mean that, in the next 50 - 100 years, their availability for Leadbeater’s Possum will be significantly diminished.
Furthermore, even if timber harvesting were excluded, the regrowth ash forests will not be capable of providing suitable nest sites for a further 150 years - assuming that ash trees must be about 200 years old before they can provide suitable nest sites. It therefore follows that the existing older-aged forest must continue to provide habitat for at least another 150 years, unless alternative silvicultural systems can be applied at an operation level (LCC 1994).
Of the 23,900 ha of older-aged forest in the Central Highlands, almost 10,000 is within the Yarra Ranges National Park, with the remaining 14,000 ha in State forest. The objective of the Leadbeater’s Possum Action Statement (CNR 1995B) is to conserve the species over its known range. To achieve this, timber harvesting is excluded from all Zone 1A possum habitat (see table below) that is, ash forest containing a certain density of mature and senescing trees. As a result, the 14,000 ha of older-aged forest in State forest referred to above has been included in the Special Protection Zone (SPZ) in the proposed Central Highlands Forest Management Plan. Zone 1B habitat, as defined in the table below is also protected from timber harvesting at least until it no longer provides suitable Leadbeater’s Possum habitat.

Leadbeater's Possum habitat Zones



Zone

Density of hollow-bearing trees1

Hollow-bearing tree1 type

Wattle density2

Management

1A

> 12 per 3 ha in patches > than 3 ha

Living trees containing hollows

n/a

Conservation Reserves Special Protection Zone

1B

> 12 per 3 ha in patches greater than 10 ha

Dead or living trees containing hollows

> 5 m2/ha

Conservation Reserves General Management Zone but excluded from timber harvesting while Zone 1B attributes remain.

2

n/a

n/a

n/a

Conservation Reserves General Management Zone

Notes:

1. Hollow-bearing trees are Mountain Ash, Alpine Ash or Shining Gum, either living or dead.

2. Density is expressed as basal area - the sum of the cross-sectional area of the boles of the trees.

Source NRE (1996)


Analysis of the forest containing suitable habitat is based on 21 Leadbeater’s Possum Management Units (LMUs) which have been delineated across the Central Highlands based on the extent and spatial distribution of ash-eucalypt type forest . Each LMU generally contains between 6000 ha and 10 000 ha of ash-type forest and is composed of one or more adjacent forest management blocks, containing contiguous patches of ash-eucalypt forest. The target for the conservation of Leadbeater’s Possum will be to maintain viable populations of the species in all LMUs. The LMU boundaries may be revised following completion of mapping of the ash-eucalypt forest across the Central Highlands being undertaken under the Statewide Forest Resource Inventory.
The Proposed Forest Management Plan protects all Zone 1A habitat (important for the long-term conservation of the species) according to the principles set down in the Leadbeater’s Possum Action Statement (Macfarlane et al. 1995). In addition, timber harvesting will continue to be excluded from Zone 1B habitat in State forest until either of the Zone 1B habitat attributes (the presence of dead mature or senescing trees, or wattle understorey) no longer exist.



The Plan also achieves the target of retaining patches of ash-eucalypt forest totalling 600 ha per LMU in 15 of the LMUs. Ash-eucalypt forest in the six remaining LMUs is primarily 1939 regrowth. This forest will not start to develop Zone 1A habitat characteristics for another 50 to 100 years. By the year 2100, at least 44% of the total area of ash-eucalypt forest in the Central Highlands will be over 150 years old (see Table below). This future relative abundance provides significant opportunity to adapt the Leadbeater’s Possum reserve system to future management requirements. (NRE 1996).

Area by age-class distribution of ash-eucalypt forest included in conservation reserves or the SPZ in the Central Highlands from 1996 to 2146





1996


2046

2096

2146

Ash-eucalypt forest less than 100 years old

61 400 ha


4900 ha








Ash-eucalypt forest 100 to 150 years old




56 500 ha


5100 ha

500 ha


Ash-eucalypt forest more than 150 years old

23 900 ha


23 900 ha


80 200 ha


84 800 ha






    Notes:

    1. Areas are expressed to the nearest 100 ha.

    2. The total area of ash-eucalypt forest in the Central Highlands is 181 000 ha. Of this, 89 500 ha or 49% is in conservation reserves or the SPZ (includes 4200 ha of ash-eucalypt forest which is considered unstocked from a commercial point of view).

    3. Assumes no wildfires

    4. Assumes that existing ‘mature’ forest is over 150 years old

    5. Assumes that unstocked ash-eucalypt forest in conservation reserves and the SPZ will not be restocked

    6. Excludes ash-eucalypt forest in GMZ - Other and in Other Public Land

To analyse areas of forest which would form the most appropriate future system of retained habitat for Leadbeater’s possum a computer model is being used. In the model, the forest is ranked according to its suitability for Leadbeater’s Possum habitat, using age class, density of live and dead hollow-bearing trees and slope data, for each patch of forest. The model will produce a series of options of suitable habitat. Within each LMU, patches (generally greater than 50 ha) of ash-eucalypt forest will be retained (with a target of at least 600 ha in each LMU). On completion of the modelling and subsequent field authentication, the zoning system established in the Proposed Forest Management Plan will be reviewed in the light of the options provided by the model. Where possible, the patches will be linked through the linear reserve system. In State forest, the patches will form part of the SPZ (NRE 1996).





NRE is also continuing research into, and operational trial of, the retained overwood silvicultural system in regrowth stands adjacent to stands of veteran trees with the aim of promoting mixed-aged forest that could benefit Leadbeater’s Possum.
Other detailed prescriptions relating to the management of habitat for Leadbeater’s Possum in timber production forests in the Central Highlands are outlined in the Action Statement (Macfarlane et al. 1995), and the proposed Forest Management Plan. A Recovery Plan is currently in the final stages of preparation.
Timber harvesting threatens a range of fauna species through its short-term effect of habitat removal, and more importantly, by its medium and longer-term effect of producing even-aged regrowth forests that are less suitable for some species than older forest. Ecologically mature or old-growth forests are generally more structurally diverse than regrowth forests and provide a greater range of foraging substrates. Mature forests may support higher populations and diversity of bird species (Gilmore 1985, Scotts 1991). Many species, including arboreal mammals and forest birds, require hollow-bearing trees for roosting or nesting (Smith and Lindenmayer 1988, Davey 1993). For species such as the Sooty Owl and Powerful Owl which utilise large tree hollows for nesting, have large home-ranges and are partly dependent on hollow-dependent prey, loss of hollow-bearing trees as a result of timber harvesting operations is a major threat (Milledge et al. 1991). The 1939 fires significantly reduced the availability of hollow bearing trees and old growth forests in the Central Highlands. Timber harvesting is therefore confined to regrowth stands to ensure protection of remaining mature and old growth forest in Ash forests. No harvesting of old growth in mixed species forests is permitted in the Central Highlands.
The Central Highlands Proposed Forest Management Plan (DNRE 1996b) management guideline for Powerful, Sooty and Masked Owls provides for the maintenance of good quality habitat for at least 60% of the species’ estimated populations occurring across the Central Highlands. Both conservation reserves and State forest contribute to conservation of owl habitat. Forest reserved specifically for owls may include: areas surrounding known owl breeding sites; areas with confirmed sightings of owls over the last five years; and areas containing suitable habitat. Areas of habitat reserved for each species includes: Powerful Owl 500-800 ha in the SPZ; Sooty Owl - 300 to 500 ha in SPZ; Masked Owl: 500 ha in SPZ. Other conservation measures include: a 250 m radius SMZ around nesting or residence sites for trees used within the last 5 years, within which nest trees and all trees within a radius of 100 m from the nest tree will be protected and within which timber harvesting operations, road construction and other activities likely to disturb breeding activity will be excluded during the breeding season; retention of ash eucalypts originating before 1900 in timber harvesting coupes; protection of a minimum of 30% of each EVC; and protection of at least 60% of old-growth forest. In reality, virtually all old growth forest is protected under the Central Highlands Proposed Forest Management Plan except for some of the drier forest types in the north-east of the region where at least 60% is protected but none is used for timber production.
Alteration of forest structure by timber harvesting can cause some areas of forest to become sub-optimal. Species may need to expend more energy to forage in sub-optimal habitat, the ability to reproduce and dispersal may be curtailed, the likelihood of predation and the probability of mortality resulting from changes in fire regimes and other environmental factors may increase (Norton and Dovers 1994). The Code of Forest Practice for Timber Production (NRE 1996a) (Code) sets minimum standards for forest operations. It provides principles and guidelines for regional prescriptions controlling timber production activities in State forest. The Code aims to ensure that environmental values and water catchments are protected by careful operational planning, reservation of appropriate areas and vegetation corridors. Riparian and other vegetation must be retained within at least 20m of a permanent stream and at least 10m either side of temporary streams and drainage lines. Trees must not be felled within such areas and timber extraction roading should be planned to minimise impacts on catchments. Such prescriptions will benefit species associated with riparian habitat including Large-footed Myotis and Broad-toothed Rat. The Code also provides for retention of wildlife habitat at the coupe level. Prescriptions have been developed to link protected areas and reserves with wildlife movement corridors, to retain habitat trees, to retain and protect biologically significant habitats and to modify harvesting.
Loss and fragmentation of habitat as a result of timber harvesting, particularly clearfell logging, is potentially a major threat to the Spot-tailed Quoll (C. Belcher pers. comm.). There is a lack of detailed ecological information concerning this species and very little is known of its occurrence in the Central Highlands. There are very few records and there have been no systematic surveys making appropriate management difficult (Mansergh and Belcher 1992). Management actions for Spot-tailed Quoll specified within the Proposed Central Highlands Forest Management Plan are: approximately 500 ha to be included in the SPZ within a 3 km radius from the record site; no threatening poisons to be used within 1 km of a record less than 5 years old; identification of 50 sites in the Central Highlands before review of the management plan; and a minimum 200 m buffer around denning/latrine sites (NRE 1996b).
The Giant Burrowing Frog is known to use a wide range of forested environments and has been recorded substantial distances from likely breeding sites (Mazzer 1994). The effect of fragmentation of the forest environment on this species is unknown although it may be significant (G. Gillespie pers. comm.). Intended management actions outlined in the Action Statement for this species (Mazzer 1994) are only relevant to post 1980 records. There is only one historic breeding record of the Giant Burrowing Frog within the Central Highlands; it has not been recorded since and the status of this cryptic species is unknown.
Timber harvesting may lead to increased levels of sediment in streams which in turn can impact on species reliant on instream habitat. Furthermore, regrowth Ash forest which regenerates following timber harvesting operations may potentially alter stream flow and perenniality within catchments. Loss of forest cover may increase light reaching streams and thereby stream temperatures (Campbell and Doeg 1989). Given these implications, timber harvesting is considered a major threat to the Spotted Tree Frog. Populations may be detrimentally affected by altered streambed conditions and changes to water quality and flow. Changes in flow rates and increased sedimentation may affect the viability of eggs, the survival of tadpoles and the availability of egg deposition sites (Gillespie and Hollis 1996, Robertson in prep.). The full range of habitats used by the Spotted Tree Frog during different growth stages and different seasons is unknown. The provisions of the Proposed Central Highlands Forest Management Plan provides for a 300m special protection zone buffer, which excludes timber harvesting either side of streams with confirmed or potential Spotted Tree Frog localities.
The Large-footed Myotis feeds on aquatic insects and fish; altered stream conditions as a result of timber harvesting operations may indirectly impact on this species by affecting its prey (L. Lumsden pers. comm.). The Proposed Central Highlands Forest Management Plan management actions specify that known colonies of this species are protected by a 100 m riparian buffer on both sides of streams.
Until recently the Baw Baw Frog was believed to be confined to the Baw Baw Plateau, within an area of 80 km2 (Malone 1985), which is primarily within the Baw Baw National Park. The species has recently been recorded at lower elevations (1100-1300 m) from Montane Wet Forest (Eucalyptus delegatensis and E. nitens) in areas available for timber harvesting (G. Gillespie pers. comm.). Adults of this species are known to use habitat adjacent to and some distance from breeding sites. Very little is known of movements of juveniles and sub-adults (Hollis 1996). Timber harvesting activities have the potential to affect local populations of the Baw Baw Frog, destroy sheltering sites, affect prey abundance, alter micro-climates, fragment habitat and allow the invasion of exotic weeds and predators (Gillespie and Hollis 1996, Hollis 1996). A survey of areas of potential Baw Baw Frog habitat in the Montane Wet forest and Subalpine Wet Heathland within State forest on the south-west face of the Baw Baw escarpment was conducted in October 1996-March 1997. Until the results of the survey become available, the Proposed Central Highlands Forest Management Plan excludes timber harvesting from areas containing potential habitat for the Baw Baw Frog in Montane Wet Forest above an altitude of 1100m (NRE 1996b).

Predation and competition by introduced species

This category covers predation by introduced species (e.g. feral cat, fox, trout) as well as competition by introduced species for resources such as food or shelter. It does not include predation or competition by native species.
Foxes and cats are widespread throughout Victoria, occurring in most habitat types. Predation by introduced animals (primarily foxes and cats) is recognised as a major threat to the Brush-tailed Phascogale (Soderquist 1993) and the Broad-toothed Rat. Broad-toothed Rats occur in highly localised, disjunct populations in the Central Highlands and are therefore particularly susceptible to population declines from predation (Menkhorst 1995). Predation of the eggs and tadpoles of Spotted Tree Frogs by trout represents a major threat to this species in the Central Highlands. Trout may be the most abundant fish species in streams within the Central Highlands (T. Raadik pers. comm.). Predation by introduced species is considered a moderate threat to five species, including Swamp Antechinus, Squirrel Glider, Eastern Horseshoe Bat and Common Bentwing Bat. Squirrel Gliders require continuous tree cover for movement, and may cross open ground in fragmented habitat, making them more susceptible to predation (Alexander 1981). Predation by introduced species is considered a minor threat to 11 species.
Competition by introduced species for food and nest hollows is recognised as a major threat to Masked Owl, Spot-tailed Quoll and Dingo. Foxes may compete with Masked Owls for rabbit prey. While it is not known how important introduced prey is to the diet of the Masked Owl, competition for prey with foxes may be a major threat to the species (R. Loyn pers. comm.). There is some degree of dietary overlap between cats, foxes, feral dogs and Spot-tailed Quolls, however, the effect of these introduced predators on Spot-tailed Quoll populations is unknown (Mansergh 1984, Mansergh and Belcher 1992, Mansergh 1995c). There is also some dietary overlap between foxes and Dingoes (Brown and Triggs 1990). Although Dingoes generally feed on larger prey, competition with foxes particularly when prey is scarce, may impact on the Dingo population. The feral European honeybee is known to occupy hollow trees, and may compete for this resource with several native species which use hollows. Preferred sites for honeybees are generally within drier mixed-species eucalypt forests and may have an impact on species such as the Brush-tailed Phascogale (T. Soderquist pers. comm.).
Current predator control programs within the Central Highlands are mainly limited to trapping, shooting and baiting for wild dogs (Jeremiah and Roob 1992). Pest animal control programs within the Central Highlands include programs coordinated with adjacent landowners (Good Neighbour Program) and, where feasible, targeted programs throughout the region. The Proposed Central Highlands Forest Management Plan recognises Foxes, feral cats and wild dogs as being of particular importance for control within the region.

Pest Control

This category includes mortality of native species from feeding on poison baits (non-target poisoning) and secondary poisoning as a result of ingestion of poisoned prey. It also includes the potential impact of loss of significant food sources following control programs for introduced species such as Rabbits. Spraying of herbicides for weed control, pesticides for insect control, and food chain contamination by heavy metals are also included within this category. Pest control is recognised as a moderate threat to nine species and a minor threat to eight priority species. (Table 6.4).
Trapping, shooting and baiting of wild Dogs occurs in the Central Highlands (Jeremiah and Roob 1992); this represents a moderate threat to Dingoes and Spot-tailed Quolls. The effect on the Central Highlands Dingo population is unknown but studies from other areas have shown the effects can be intense, reducing local population numbers where control efforts are high. However, it may result in the fracture of social groups thereby resulting in an increase in breeding females (Corbett 1995). The effect of control measures on Dingoes requires monitoring and research. There is virtually no information on the Spot-tailed Quoll within the Central Highlands; there are few records of the species and the effect of wild Dog control methods are limited to research in East Gippsland (Belcher 1995c). Control of foxes using 1080 poison baits is also problematic for carnivores such as the Spot-tailed Quoll because of the risk of non-target poisoning, which can result in death of individuals or local populations (Mansergh and Belcher 1992, Belcher 1995b). Very little is known of the effects of pest control programs on the majority of species; monitoring and research is required to determine the most appropriate methods of control. Burying baits has been used as a remedial measure to reduce the incidence of non-target poisoning of species such as the Spot-tailed Quoll (Mansergh and Belcher 1992). However, studies have shown the species will dig up and ingest buried baits (Belcher 1995b). Within State forest in the Central Highlands region it is proposed that no threatening poisons are to be used within 1 km of Spot-tailed Quoll records less than 5 years old. The Proposed Central Highlands Forest Management Plan management guidelines states that resources directed to particular pest species should take into account the potential impact on the conservation of rare or endangered fauna, and programs should be monitored to ascertain effects on non-target species (NRE 1996b).
The Spot-tailed Quoll may also be susceptible to secondary poisoning by ingestion of poisoned Rabbits (Mansergh and Belcher 1992, Belcher 1995b). The Masked Owl is known to prey on Rabbits although the proportion of Rabbit prey in the diet of this species is unknown; the importance of loss of prey due to control programs including baiting and the calicivirus is unknown. There is also the risk of secondary poisoning following control programs (Peake et al. 1993, R. Loyn pers. comm.).
Insectivorous bats such as the Common Bent-wing Bat and Eastern Horseshoe Bat may be susceptible to poisoning through accumulation of pesticides (Dunsmore et al. 1994). Top order predators such as the Grey Goshawk may also be susceptible to contamination by pesticides (Mooney and Holdsworth 1988). Pesticides and herbicides may drain into streams which could impact on the Large-footed Myotis which feeds on aquatic invertebrates and fish (L. Lumsden pers comm) and Spotted Tree Frog (G Gillespie pers comm). The use of pesticides is not undertaken in public native forests in the Central Highlands. However, the use of chemicals for control of vegetation underneath powerlines in an area of known habitat of the Broad-toothed Rat is a moderate threat to this species. Vegetation management at this site is being addressed in the management of the Bunyip State Park.

Grazing

Grazing of vegetation can limit or prevent vegetation regeneration and can alter the structure and floristics of vegetation. It may result in simplification of vegetation which can be detrimental to species which require a complexity of understorey and ground layers (eg. Glossy Grass Skink). Vegetation structure and floristics can be important in terms of shelter and as a food source. Plant species may be selectively grazed, and vegetation may have different tolerances to grazing and varying abilities to recover. Grazing can also include associated problems such as trampling of vegetation, soil compaction and the spread of weeds. It may also affect the health and longevity of existing trees due to increased nutrient levels which may lead to dieback (Landsberg et al. 1990). Grazing is considered a major threat to Alpine Bog Skink, a moderate threat to the Broad-toothed Rat, Squirrel Glider, Common Dunnart, Barking Owl, Glossy Grass Skink, Alpine Tree Frog, and Baw Baw Frog, and a minor threat to 13 species. It is not considered a threat to eight species, while its significance is unknown for four species (Table 6.4).
The Broad-toothed Rat exhibits a disjunct and localised distribution which is probably a reflection of its specialised habitat requirements. Loss of habitat as a result of grazing and trampling is considered a moderate threat; however the species security has probably increased in recent years through protection of riparian forest sites and cattle being excluded from alpine sites and many other sites in which the species is found are in National Parks (eg. Baw Baw National Park) and proclaimed catchment areas (eg Upper Yarra catchment) (Menkhorst 1995). A small and increasing number of feral cattle are present on the Baw Baw Plateau (DCE 1992a). Sambar Deer are also present in the vicinity of the Baw Baw Plateau, particularly in montane forest and montane riparian thicket. Cattle graze within frost hollows, grassy sub-alpine woodland and cleared areas on the plateau and damage to vegetation and soil, although localised, is significant (Hollis 1996). This has the potential to affect Baw Baw Frog, Alpine Bog Skink and Alpine Tree Frog. The impact of grazing on the Baw Baw Frog and its habitat is unknown (Hollis 1996, G. Gillespie pers. comm.). The Alpine Bog Skink has a limited, disjunct distribution and its habitat is particularly susceptible to reduction and modification, caused by erosion, arising from grazing and trampling ; therefore, grazing is considered a major threat (P. Robertson pers. comm.). Trampling of breeding sites by cattle has the potential to cause declines of the Alpine Tree Frog however, the impact is unknown (Gillespie et al. 1995). Control of feral cattle from the Baw Baw National Park is being addressed as part of the management plan priorities for the park.
Grazing of stock on Crown land is prohibited in alpine areas in the region. Elsewhere, currently 114 ha of State forest and 127 ha of Bunyip State Park are held under grazing licences. These licences specify conditions for depasture of stock within the licensed area. Grazing licences in Bunyip State Park are not in areas where Broad Toothed Rat and Swamp Antechinus have been recorded, and in accordance with LCC recommendations, will ultimately be phased out.
Grazing on private property which contains suitable habitat for Common Dunnart and Glossy Grass Skink is a moderate threat to these species. The habitat of the Glossy Grass Skink is characterised by dense vegetation within which animals bask and forage (Hutchinson and Donnellan 1988). Grazing and trampling by cattle may simplify the structure of the vegetation, making it less suitable as habitat (P. Robertson pers. comm.).
Throughout Victoria, Squirrel Gliders are restricted to isolated remnants of habitat amid extensive farmland. In some areas the species is restricted to narrow discontinuous strips of habitat along roads or streams. In the Central Highlands the species is known from one locality near the Goulburn River. Grazing of eucalypt and acacia seedlings may limit the regeneration and development of suitable habitat for species such as the Squirrel Glider (Menkhorst 1995, J. Alexander pers. comm.). The Heritage Rivers Act 1992 provides for the protection of Squirrel Glider habitat along the Goulburn River.

Disease

The significance of disease is largely unknown for most species, and is only noted as a threat for four species. The extreme vulnerability of the Helmeted Honeyeater makes it susceptible to any such events. Similarly, the Baw Baw Frog has an extremely restricted distribution making it potentially vulnerable to disease. Disease is also considered a minor threat to Brush-tailed Phascogales and Powerful Owls. Moribund Powerful Owls are occasionally recorded, although the cause of illness is unknown (R. Loyn, pers. comm.)

Harvesting of fauna by humans

This category covers direct interference to animals by humans in the form of collection or deliberate hunting, poisoning, or trapping. Overall this threat is considered as a minor threat to the Bush Stone-curlew and Square-tailed Kite in the Central Highlands.

Clearing for agriculture or development

Extensive clearing of native vegetation for agriculture and settlement has been a significant factor in the decline of many species and is partially responsible for the current threatened status of some species. Clearing affects species directly through loss of habitat and indirectly through fragmentation and isolation of habitat; many species are now confined to small isolated remnants of habitat. As a result, local populations are more vulnerable to extinction from catastrophic events such as wildfire and more susceptible to threatening processes including predation and interspecific competition. Habitat remnants are susceptible to degradation from agricultural activities in the surrounding farmland, firewood collection, and fire protection activities. Clearing is now confined to relatively small areas on private land. If suitable habitat for particular species is largely restricted to private land, then loss of habitat may be considered significant. Clearing is classified as a major threat to Brush-tailed Phascogale, Powerful Owl and Masked Owl, a moderate threat to eight priority species and a minor threat to 16 priority species. (Table 6.4).
The impact of vegetation clearance on the biology and ecology of the Baw Baw Frog is not well understood. The Mount Baw Baw Alpine Resort is within the species distribution stronghold and clearance of vegetation for resort development is a moderate threat (Gillespie et al. 1995, Hollis 1996, G. Gillespie pers. comm.). Clearing for resort development is also classified as a moderate threat to the Alpine Bog Skink (P. Robertson pers. comm.). The Baw Baw Frog Flora and Fauna Guarantee Action Statement (James and Morey 1993) provides for NRE input into any proposed development or improvement within the Mount Baw Baw Alpine Resort that may affect Baw Baw Frog habitat.
The Brush-tailed Phascogale is known to occur in the mixed rural, urban and forested land north-east of Melbourne. Clearing for urban development causes loss and fragmentation of the species’ habitat and is a major threat (T. Soderquist pers. comm.). The Common Dunnart is also recorded around the northern outskirts of Melbourne and clearing for urban development, and the associated habitat modification, is a moderate threat to this species in the Central Highlands (J. Seebeck pers. comm.). Similarly, urban development is a threat to the Powerful Owl, particularly in forested areas close to Melbourne (R. Loyn pers. comm.) although the current population appears stable. The Barking Owl is often recorded in habitat with moderate tree cover including wooded farmland near forests or along ecotones of large forest blocks. The species is known to utilise broad strips of riverine forest along major creeks. However, isolated, narrow strips of linear habitat do not appear to be used (Robinson 1994). Clearing for agriculture and the associated fragmentation of habitat is a major threat to this species (R. Loyn pers. comm.).
This threat is significantly mitigated by the implementation of native vegetation retention controls under the Planning and Environment Act 1987. Permits are required from local municipalities to clear native vegetation.

Mining/Quarrying

Mining within the Central Highlands has, in the past, been mainly for gold with minor associated metals including stibnite and cobalt and rare occurrences of quartz (Jeremiah and Roob 1992). Several products including rock, gravel, sand, clay, and soil have also been quarried from surface and river deposits. Poorly sited quarries and borrow pits can have adverse effects on water quality (NRE 1996b). Although mining is considered a threatening process, past mining activities would have had greater impact on species than modern mining activities which are regulated through a range of mechanisms.
Mining/quarrying is a moderate threat to Eastern Horseshoe Bat, Common Bent-wing Bat, Large-footed Myotis and the Spotted Tree Frog and a minor threat to three priority species. For most of the threatened species covered by this review, the effect of mining/quarrying is either unknown or it is not classed as a threat (Table 6.4).
Mining and eductor dredging in and around upland streams can cause deterioration of upland riparian habitats. Eductor dredging is believed to alter the natural ecology of streams (Watson et al. 1991). Effects can include an increase in turbidity of water downstream of an operation, mobilisation of chemicals such as mercury, local bank erosion and increased bed erosion (Parliament of Victoria Environment & Natural Resources Committee 1994). Most of the rivers in the Central Highlands with road access are believed to have been dredged in the past. Disappearances and declines of Spotted Tree Frog populations appear to be linked to eductor dredging activities which can have deleterious effects on frog embryos, larvae and adults (Watson et al. 1991). Impacts on populations may not be restricted to the area dredged but also to habitats downstream (Gillespie and Hollis 1996). Eductor dredging activities are currently illegal in Victoria.
Species which are dependent on streams, such as the Large-footed Myotis, may also be affected by mining and extraction activities in and around streams (L. Lumsden pers. comm) if these activities affect water quality with subsequent effects on the instream fauna on which this species depends.
It is likely that the creation of mines in the Central Highlands region in the past led to an expansion in the distribution of the Eastern Horseshoe Bat and Common Bent-wing Bat. Renewed interest in reworking old mines represents a potential threat to bats which rely on such sites (Lumsden et al. 1991). It is proposed that known colonies of Eastern Horseshoe Bat are to be protected within the Central Highlands region by a 100m buffer (NRE 1996b). There are, however, mines within the region which have not been surveyed for the presence of these species. There is the potential that there is an Eastern Horseshoe Bat maternity colony in the Central Highlands. (Lumsden et al. 1991).
Mineral exploration, mining and extractive industries are not permitted in Reference Areas, nor in National, State and Wilderness Parks except where a tenement or application pre-dates the Park and the Minister responsible for the National Parks Act consents. For restricted Crown land, including most conservation reserves, the consent of the responsible Minister is required, which may be conditional. Mining and exploration operations require a licence and work plan approved by Minerals and Petroleum Victoria (a division of NRE) before exploration or mining works can be undertaken. For mining and exploration on unrestricted Crown land, relevant land management divisions of NRE can comment on licence applications, conditions and work plans, which can address environmental considerations such as biodiversity conservation. Similarly, extractive industries require a work plan and a consent of the relevant Minister for extractive operations. The Proposed Central Highlands Forest Management Plan (NRE 1996b) specifies that consent to extraction activities should be based on: consideration of the impact of the proposal on the existing zoning scheme, the availability of alternative resources on freehold land or other sites, and the environmental and other impacts of the proposal. No new extraction activity will be permitted within the Special Protection Zone (SPZ) unless it will make a significant contribution to the regional economy, and unless the values within the SPZ can be maintained or provided elsewhere. As a minimum, licence conditions, Work Plans and proposed NRE managed extraction activities should address biodiversity considerations, protection of catchments and streams, rehabilitation and revegetation of the land and impacts on other forest values including recreation and tourism, sawlog resources, cultural and landscape values and maintenance and management of roads (NRE 1996b).

Roading

This category includes habitat destruction and alteration of hydrological regimes by roading. Roading can directly destroy habitat, create barriers to movement, increase the potential of erosion and weed invasion, and increase water turbidity and siltation if associated with creek crossings (Lumsden et al. 1991). There is evidence that introduced predators such as Foxes utilise tracks as pathways (May and Norton 1996). The principal sources of sedimentation are likely to be associated with unsealed roads and tracks. Of greatest concern are roads and tracks that are close to streams, and poorly constructed or maintained tracks on erodible soils, especially at stream crossings. Extra attention is now paid to planning the road and track network to avoid threatened species habitat, minimise environmental damage and provide high standard stream crossings. All new roads and tracks used for timber production must be built to standards outlined in the Code of Forest Practices for Timber Production (NRE 1996a). However, many roads and tracks were built prior to introduction of the Code and do not meet today’s standards, and accordingly this is a significant threat. Roading is considered a major threat to the Alpine Bog Skink and Spotted Tree Frog, a moderate threat to the Squirrel Glider and Large-footed Myotis, and a minor threat to a further 14 species. Its impact is unknown for eight species and it is not considered a threat for seven species (Table 6.4).
The Alpine Bog Community, habitat of the Alpine Bog Skink, is particularly vulnerable to disturbance. This community is listed as threatened under the Flora and Fauna Guarantee Act 1988. Construction of roads may impact on the Alpine Bog Skink directly through habitat destruction and indirectly through the diversion of water and the introduction of pathogens and non-bog plant species (P. Robertson pers. comm.). The likelihood of road construction within the Alpine Bog community, the habitat of Alpine Bog Skink, is low. However, there are a range of processes (eg Code of Forest Practice for Timber Production) in which flora and fauna values are addressed prior to the approval of the construction of new roads within public land.
The Large-footed Myotis is largely dependent on aquatic prey. A decline in aquatic prey as a result of disturbance from roading is a moderate threat to this species in the Central Highlands.
Construction of roads and tracks results in the exposure of soil which is then vulnerable to erosion and weed invasion and can cause increased sedimentation of streams and alteration of riparian habitats. Roads adjacent to streams and road crossings of drainage lines and streams throughout a catchment, may cause an increase in water turbidity and an increase in sediment loads reaching streams (Lumsden et al. 1991, Gillespie and Hollis 1996). These changes can be detrimental to the Spotted Tree Frog by affecting the growth and survival of eggs and tadpoles or by changes to the general characteristics of the riparian habitat which may affect adult recruitment, breeding or survival (Watson et al. 1991). The Central Highlands Proposed Management Plan (NRE 1996b) management prescription for Spotted Tree Frog includes the following actions relating to roads and tracks in catchments where the Spotted Tree Frog has been recorded: new roads or stream crossings should be constructed according to recommendations outlined in O’Shaughnessy (in prep.); all roads or tracks not required for management, harvesting or fire protection purposes should be progressively closed and rehabilitated; and roads or tracks which are retained should be upgraded to standards outlined in O’Shaughnessy (in prep.), and where appropriate seasonally closed; and the number of stream crossings over permanent and temporary streams or drainage lines should be minimised. Furthermore, the management prescription states no new roads or stream crossings should be constructed within 1 km upstream of confirmed and potential localities of the species (NRE 1996b).
In State Forest, all new roads and tracks must be built to comply with the Code of Forest Practices for Timber Production which includes goals and guidelines for planning, location, design, construction, maintenance and use of timber extraction roads and stream crossings. These guidelines include measures to minimise risks to environmental values such as soil and water quality. The Proposed Central Highlands Forest Management Plan (NRE 1996b) includes management guidelines for the determination of the road network to be maintained in State forest. Priority areas include catchments containing threatened fauna that are susceptible to increases in stream sedimentation; catchments known to contain the Spotted Tree Frog are highlighted. Guidelines are also outlined for road and track closures. NRE will prepare in consultation with water catchment authorities an annual road works plan that specifies the maintenance requirements of roads and tracks in restricted access catchments (NRE 1996b).
Due to extensive clearing in the past, much of the habitat of the Squirrel Glider is confined to narrow strips along roads or streams (Menkhorst, 1995). The species requires continuous tree cover for movement; gaps can prevent access to adjoining habitat and Gliders attempting to cross open space on the ground are highly vulnerable to predation. Road maintenance and widening can result in loss of canopy connectivity, and loss and degradation of isolated remnants of suitable habitat and is a moderate threat to the species in the Central Highlands (Alexander 1989, J. Alexander pers. comm.). The only Central Highlands record of this species is from the riverine forests along the Goulburn River (which is designated as a Heritage River) and therefore the potential threat described above is unlikely to be significant.

Recreation

A range of recreational activities which can damage or destroy habitat or disturb fauna. This includes use such as 4-wheel driving, trail bike riding, cross country and downhill skiing, hiking, fishing, horse riding and camping. Such activities can directly remove or trample vegetation, cause soil compaction, pollution and sedimentation of streams, erosion and the spread of weeds. Recreation activity is considered a major threat to the Alpine Bog Skink, a moderate threat to the Swamp Antechinus, Spotted Tree Frog, Alpine Tree Frog and Baw Baw Frog, and a minor threat to seven species. The majority of species covered by the review are not considered threatened by recreation, and it is an unknown threat for five species (Table 6.4).
The habitat of the Alpine Bog Skink includes subalpine heath and sphagnum bog communities. These communities are easily damaged and take a long time to recover due to the brief growing season and harsh climate of Alpine areas (James and Morey 1993). Recreation activities including vehicular use, snow sports, slope grooming and lift construction and trampling by humans can cause loss and degradation of the habitat of the Alpine Bog Skink and is a major threat to the species (P. Robertson pers. comm.). The impact of recreational activities, particularly skiing and hiking on populations of the Baw Baw Frog, is unknown. The Baw Baw Plateau is traversed by a network of bushwalking tracks and ski trails. The placement of some trails, particularly in wetland habitats, has in the past resulted in loss and degradation of vegetation during construction and through use has altered drainage patterns. This damage may be detrimental to local breeding populations. In addition, existing large areas of cleared trails and ski areas may impede dispersal and movement and result in increased predation (Hollis 1996). The Alpine Tree Frog is restricted to high montane, subalpine and alpine altitudes. The development of snow sport facilities, including ski trails, in areas of this species distribution is likely to adversely affect this species through modification of breeding sites and non-breeding habitats (Gillespie et al. 1995).
The Baw Baw National Park Management Plan (DCE 1992a) recommends that high priority be given to the protection of the Wet Alpine Heathland by relocating walking tracks away from this community or providing boardwalks where necessary on the Alpine Walking Track, and relocation of nordic ski trails when snow cover is insufficient to protect vegetation. Provision of boardwalks along the Australian (Alpine) Walking Track has been undertaken on the majority of this track in the Park, and an ongoing system of discouraging visitor use of ski trails where snow cover is insufficient to protect vegetation is implemented within the Baw Baw National Park. The park management plan also recommends that Baw Baw Frog populations will be protected by: conducting surveys to confirm the distribution and ecology of the species, protecting large populations in Special Protection Areas and monitoring the range of habitat on the plateau. Intended management actions outlined in the Action Statement for the Baw Baw Frog include monitoring and management of the effects of recreation on the species and its habitat (James and Morey 1993). The Actions Statement also provides for NRE input into any proposed development or improvement within the Mount Baw Baw Alpine Resort that may affect Baw Baw Frog habitat. These actions may also benefit populations of the Alpine Bog Skink and Alpine Tree Frog.
All records of the Swamp Antechinus within the Central Highlands are from Bunyip State Park. Recreational use of vehicles including 4-wheel drives and trail bikes are popular in the park and may cause habitat degradation through heavy use of roads and tracks which in turn may impact on the swamp habitat of this species; this is thought to be a moderate threat to the Swamp Antechinus (D. Drangsholt pers. comm.). A management plan is currently being prepared for this park.
Recreational activities including camping, fishing, horse riding and vehicle use occur at many of the sites from which the Spotted Tree Frog has disappeared (Gillespie and Hollis 1996). Recreational fishing and bait collection, which includes using the frogs as bait and disturbing stream habitat while in search of other live bait, may be a significant cause of Spotted Tree Frog population declines (Watson et al. 1991). The Proposed Central Highlands Forest Management Plan, in addition to providing for determination of the road network to be maintained in State forest, proposes to close and rehabilitate the Taponga River camping ground which is adjacent to a known population of the Spotted Tree Frog (NRE 1996b).



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