Phytophthora cinnamomi (Cinnamon Fungus) and Bush Dieback

Managing and Monitoring Phytophthora

Monitoring Phytophthora in the Otways

Investigations of phytophthora distribution and impact in the Yaugher and Forest area (an in particular along mountain-bike tracks recently constructed in the area) are underway. The findings will be presented here as they are gathered.

The investigations/presented information will include:

Maps of the distribution of Phytophthora outbreaks (presented under the Yaugher maps tab above).
Descriptions of features such as tracks and topography that facilitate or impede it's spread.
Details of actions, events, works and mitigation measures that are likely to enhance or retard the spread.
Lists, descriptions, distribution maps and photographs of every habitat, flora species and fauna species likely to be impacted, along with explanations of the nature and estimated degree of the impacts on each.

Managing Phytophthora

The following recommendations for management of phytophthora in bush ecosystems of the Forrest-Yaugher mountain-bike track network have been presented to mountain bike track builders and to DSE Forestry manager for the Colac and Forrest area. To date recommendation 21 has been implemented on two occasions.

Suggested mitigation measures to slow Phytophthora spread due to the construction and use of mountain-bike tracks around Forrest and elsewhere in the Otways

Informing the community
On-ground mitigation measures
Managing access and use
Mitigation measures during mountain-bike race events
Planning for future track/road construction
Offsets

A. Informing the community

The communities of Forrest and other Otway townships and districts should be informed about phytophthora, its impacts, activities that facilitate its spread, and mitigation options. This may (for example) be achieved through mail outs, media articles and the afore-mentioned signage.
The mountain-bike user group involved in developing and constructing the track network should:

Ensure that all members are fully aware of the phytophthora threat.

Ensure that all members understand the actions that they should take to reduce the likelihood that they spread phytophthora.

Should undertake a review of environmental risks associated with each mountain-bike track in use, being constructed, or being planned in Victoria by the group.

B. On-ground mitigation measures

No more unnecessary tracks should be built through areas of sensitive vegetation in the vicinity of Forrest or elsewhere in the Otways.
If tracks are built, then phytophthora risk assessment and mitigation must be explicitly addressed during planning, construction, maintenance and use.
The design and manner of construction in which the Yaugher tracks is clearly substandard and unnecessarily damaging. This should be investigated by the appropriate authorities in an open manner.
Many of the tracks cross from infected areas to uninfected areas. Many have been cut directly through extremely sensitive vegetation including examples where numerous mature grass trees were removed, wher grass-trees are adjacent to tracks, where blocks of grass-trees are downslope from tracks. Other tracks have been cut directly through dieback zones. An infection risk assessment should be conducted and risk reduction measures should be implemented.
All drainage works influencing runoff that will cross tracks or associated infection zones should be reviewed, and where necessary to reduce infection risk should be modified.
Phytophthora is favoured by acid soils. The soils of woodlands of the Yaugher Cemetery are highly acidic – particularly where grasstree-heath understorys are present. In Tasmania and Western Australia phytophthora risk is reduced by spreading crushed limestone on tracks. This measure should be implemented around the Forrest trail network and at trail-head car-parks. Parks Victoria and Forestry should consider this measure in all car-parks and campgrounds in the Otways. (Crushed dolomite would probably also be effective.) There is a possibility that changing soil pH may kill some species such as grasstrees, so the risks and benefits of this option should be carefully considered and the outcomes monitored and assessed.
The antifungal agents phosphite and Phytoclean (benzalkonium chloride) should be assessed for use managing phytophthora on the Otway-Forrest mountain-bike tracks. Phosphite can be applied as a foliar spray, a soil drench, or injected into plants. It provides a degree of protection to infected plants, is used to sterilise vehicles and equipment, and may reduce the infection risk in surface soils. However, it does not eliminate phytophthora from the soil. At high application rates, phosphite and some chemicals that are used to enhance its effect can be toxic to plants and to fauna such as frogs. Therefore a careful assessment needs to be made to determine the application rates and circumstances in which it can assist in controlling phosphite along the tracks. (Phytoclean is widely used to sterilise equipment and vehicles.)
Rigorous infection control procedures should be enforced during track maintenance.
Antifungal wash-down / disinfection facilities (using Phytoclean) should be constructed at all entry points to the trail network, and signage should state that it is a condition of entry that all bikes and gear be disinfected on entry and exit to each individual track. (Methylated spirits is used as a disinfectant, but will evaporate quickly. Bleaches such as hypochlorite are less effective and are corrosive). An effective design for such a facility might include the following features:

A shallow trench constructed with concrete. It should have a profile that allows uses to easily roll bikes through it. A potentially suitable design would be to make it about 3 or 4 m long x 1 m wide x ½ m deep in the centre sloping to zero depth at either end. It should not be possible for users to ride through the pit at speed (thereby splashing antifungal agent out of the structure and on to the rider). The structure must be designed so as not to collect rainwater that might cause it to overflow; it will therefore require an easily liftable lid (which could be hinged on side) or a roof.

For scrub-downs in circumstances where mud has been sprayed onto a bike frame or the user - a leaning post or rail on a concrete pad should be provided, along with a brush, a tub, a tap and a disinfecting agent dispenser. Because users are more likely to be exposed, methylated spirits (if effective) might be a better choice of agent as it is less toxic.

An in-ground tank and drains at the bottom of the pit and at the off-flow side of the wash-down pad will be needed to enable drainage to be collected (so as not to contaminate groundwater and nearby waterways/drainages).

A tank will be needed to provide water. If a roof is provided over the structure then this can be used to capture rain – thereby reducing the maintenance effort required to keep the tank topped up.

A tamper-proof antifungal agent container and dispenser are required to enable the pit to be dosed.

The antifungal agent mix should include a dye that enables users to gauge the concentration of the agent in the pit water.

The ground around the facility should be surfaced with crushed limestone or dolomite (the high pH will prevent or reduce phytophthora infection around the facility.

The facility must be regularly checked and maintained.

Clear signage explaining use of the facility must be provided (including an indication of the dye intensity that is indicative of an optimal concentration and a clear warning of health/toxicity risks.)

The trail network should be redesigned so as to ensure that entry and exit to individual tracks and to the network as a whole is always via a disinfection facility.
It might be feasible/desirable that tracks be sprayed with a phosphite or Phytoclean prior to race events (if an assessment determines such an application to be effective and not unacceptably toxic to flora and fauna).
Tracks should be re-routed away from infection zones, from areas where they go through patches of mud, and away from particularly susceptible vegetation. Where rerouting is not feasible, or habitat destruction caused in doing so is unacceptably high, then tracks should be closed.
The likelihood that phytophthora is transmitted or picked up by bike wheels is increased if contact with roots or damage to trunks occurs. Tracks should not pass so close to susceptible plants that contact with or damage to roots or trunks occurs.
Where tracks unavoidably must cross permanently or seasonally wet areas, duck-boarding should be constructed to prevent bikes picking up and spreading infected mud and soil.
Earth features have been created that are collecting water and which will become muddy. These need to be drained (with appropriate and effective disinfection of equipment used in the drainage works), and/or should be treated with dolomite or crushed limestone and/or phosphite or Phytoclean.
In at least one place a trench/burn has been cut down a slope using an excavator or bobcat. This shows signs of early erosion, which will eventually sending a plume of potentially sediment down-slope. Such structures should be closed and rehabilitated.

C. Managing access and use

The track network should be closed (to users and maintenance personnel) at times when phytophthora is particularly active and infectious (during warm wet periods in spring and autumn). The closure regime might be seasonal, but should include triggers for unplanned closures following unexpected periods of high rainfall.
All entrants to mountain bike championships and races should be made aware of the situation and should be provided with disinfection facilities at race-meets, the use of which should be a mandatory condition of participation.

D. Mitigation measures during mountain-bike race events

As specified in point 5, the recently constructed track through an exceptionally pristine block of heathy woodland below the Yaugher cemetery and adjacent to the Forrest – Barwon Downs and Yaugher roads should not be used by competitors and should be permanently closed.
Portable/temporary antifungal wash-down facilities should be made available at all staging points for race events through the Otways. Such a facility might be a large plastic tray with a suitable drainage outlet.
Race events should not be held during (warm wet) seasons when phytophthora is most highly infectious.

E. Planning for future track/road construction

A review should be undertaken to assess the circumstances that led to the construction of the Forrest-Otway mountain-bike trail network in the absence of any effective consideration or action to account for or mitigate against phytophthora and other ecologically degrading impacts. The review should include recommendations of measures that can be put in place to ensure that the phytophora threat is adequately addressed in future projects and works. Note: Phytophthora is currently not adequately addressed during a large proportion of projects and works in which it constitutes a significant risk. As such, it should be acknowledged that the conduct of the planners and implementers of this project has not been outside the realms of normal practice.
In future, the phytophthora threat should be a primary consideration during the planning of recreational access to bushland areas in the Otways and elsewhere.
In future, the phytophthora threat should be a primary consideration during planning decisions pertaining to the designation and management of national parks, forest parks, reserves etc.
An Otways phytophthora management strategy should be developed and implemented. This should include assessment of distribution, risk activities, and the likely impacts of phytophthora on each vegetation class and on the flora and fauna dependent on each of these, and on the local economy and Otway communities.
Local governments should explicitly acknowledge the nature and degree of the threat, and should develop and implement appropriate planning and works strategies and practices.
The construction of the network will inevitably lead to in the loss of habitat, flora and fauna populations (even if all mitigation measures are implemented). The expected phytophthora impact on ecosystems, flora and fauna should therefore be assessed. In response, strategies, programs and funding arrangements will be needed in order to mitigate the losses that will inevitable ensue.
A separate mountain-bike user’s phytophthora control strategy should be developed and implemented – particularly during races.
Strategies should be developed and implemented that address the threat mediated by other recreational users such as motor-bike, horse riders, 4WD enthusiasts and the works departments of local government and state agencies and departments.
The effectiveness of all strategies should be regularly (annually) reviewed.

F. Offsets

Under Victoria’s ‘Victoria's Native Vegetation Management Framework for Action’ there is a pre-eminent target of achieving at a minimum ‘no net loss’, and ideally a ‘net gain’ in native vegetation and habitat (measured in ‘habitat-hectares’). Where activities are undertaken which cause the degradation or loss of vegetation/habitat extent and quality this should be compensated by the creation or reservation of an equivalent amount of habitat hectares in a comparable vegetation type nearby or elsewhere. The construction of the Otway-Forrest mountain-bike trail network will inevitably cause a significant habitat-hectare loss. The expected loss should therefore be quantified and either a means of compensating for that loss should be enacted, or a dispensation applied for.