Recovery Action Plan for Grey Box community

Review of the State and Transition Model

Nield and Sinel (2010) undertook a field validation of the State and Transition Model for Grey Box Woodlands. They noted that most sites in the semi-rural areas, particularly the Onkaparinga Hills and Willunga Basin areas would fit in a 3b, 4, 5a, or 5b state. The sites within the National Parks and Reserves that have had time to recover from disturbance or have benefited from active conservation activities are mostly state 1, 2 or 5a and the hills face zone sites on steeper sloped with moderate depth soil were mostly 5b, 5c, 5d, 7, 8, and 9.

They also noted that it was difficult in the field to confidently categorise sites into states 3a and 3b, and 5a and 5b. They also observed that if states 3a and 3b had been grazed, but not for a period of time, and were strategically managed, there was no state that currently existed that allows for this condition, unless some of the indicators of 3a or 3b were ignored. They also found it very difficult to reconcile when two visually different sites can theoretically fit into the same state. This occurred particularly with State 1, where woodlands in very good condition and very poor condition were allocated the same state status.
As such it is recommended that a new state be added to the model. This state, whilst in some ways reflecting State 11, represents best practice management of sites that, whilst degraded, still provide significant values, but are unlikely to ever satisfy the full criteria for State 1. This state would in most instances still fulfil EPBC Criteria for Listing as Endangered Grey Box (E. microcarpa) woodland. This state would also be important if the State and Transition model were used as part of an overall monitoring strategy (as discussed in section 3.1), as it more clearly relates to biodiversity value than State 11. A proposed series of indicators for this state is provided below:

5.4.13.State 1b: Remnant Depauperate Woodland

Species richness	Moderate species richness. Geophyte diversity generally low-moderate (<10 species).
Indicator species	Lack of rare herbaceous species e.g. Dianella longifolia, Eryngium rostratum, Glycine tabacina. Orchid species generally absent. Herbs dominated by species tolerant of long term grazing, such as Vittadinia species Native grasses common
Structural diversity	In addition to open E microcarpa overstorey: Very open mid-layer of shrubs, scattered or small patches. Most common shrubs are grazing resilient species. Ground layer moderate range of species but herbaceous species cover generally low (<5% cover) with native grasses prevalent (to 50% cover).
Ground cover	Soil crust may be present
Regeneration	Mix of original and regrowth trees
Weeds	Grassy weeds generally prevalent (up to 50% cover). Herbaceous weeds common. Woody weeds sparse to absent.
Tree health & habitat	Healthy canopy, many younger shorter trees, sometimes coppiced, fewer trees with hollows
Tree density	Trees may be at higher densities during recovery phase
Grazing pressure	Grazing managed for biodiversity
Nutrients	Moderate nutrient loads may be present
Tree cutting	Historic timber cutting and ring-barking

Figure 5.4.13: Grey Box Woodland, Shepherd’s Hill Conservation Park. Management intervention has removed grazing and controlled woody weeds, but long term degradation means the site is depauperate of species, and is unlikely to be able to reach State 1. However, the site still provides significant habitat values, and should be recognised as such.

5.5.Appendix E: Managing native vegetation in roadsides

Purely because of its linear nature, roadside vegetation is susceptible to gradual degradation through a range of activities. This degradation can be compounded if soils are disturbed or compacted by machinery or if low native shrubs or native grasses are unintentionally driven over or cleared. Not only can native plants be unnecessarily destroyed, but conditions can also be made unsuitable for natural regeneration and management problems can be created for adjoining landholders.

Examples of the types of threats to native vegetation on roadsides include:

• 
  inappropriate fire prevention methods (e.g. grading / ploughing)
  
• 
  pesticide drift from neighbouring property
  
• 
  clearing for fence replacement (excessive or inappropriate method)
  
• 
  clearing for new driveways (excessive or poorly located)
  
• 
  weed invasion from neighbouring property
  
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  excessive seed harvesting
  
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  firewood collecting
  
• 
  disposal of rubbish and waste materials
  
• 
  inappropriate or insensitive weed control methods (e.g. boom spraying)
  
• 
  inappropriate or insensitive vermin control methods
  
• 
  poorly designed new road construction (realignments, widening)
  
• 
  poorly managed roadwork activity (e.g. stockpiles, turning areas)
  
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  incremental clearance along road edge when grading unsealed roads.
  
• 
  inappropriate vegetation control methods for sight distance
  
• 
  poor management of grading spoil (placement in roadside or table drain)
  
• 
  excessive drain clearing or inappropriate disposal of drain spoil
  
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  installation of services where cleared land exists elsewhere
  
• 
  insensitive methods used to maintain services
  
• 
  planting within intact native vegetation (e.g. trees in native grassland)
  
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  grazing by stock or rabbits
  
• 
  off-road vehicles
  
• 
  plant disease (e.g. Phytophthora, Mundulla Yellows)
  
• 
  inappropriate fire regimes
  
• 
  changes to hydrology
  
• 
  dryland salinity
  
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  lack of active management
  
• 
  senescence (old age)
  

These detrimental activities can occur for a number of reasons, but can be grouped into four categories, each of which may require a different approach to minimise or eliminate the risk. Threats to roadside native vegetation can occur due to:

• ignorance of the law – e.g. clearance for fencelines by adjacent landholders, or seed collection;

• accidental clearance – e.g. vehicles parking on roadside, grading a little wider each time, or inappropriate weed control methods;

• illegal use – e.g. domestic waste and weed dumping, or sheep and cattle grazing

• inaction – e.g. weeds and pests spread over time if not actively controlled.

5.6.Appendix F: Minimal Disturbance Weeding Techniques

The following section has been sourced and adapted from the following documents:

Adelaide and Mount Lofty Ranges Natural Resources Management Board (undated). Weed Management Techniques. Government of South Australia.

Basnett, G. and Ezis, D. (2010). Briefing note on the principles of minimum disturbance techniques and how they benefit biodiversity conservation. Department for Environment and Natural Resources.

Robertson EL (2010) Restoration of Grassy Woodland Watiparinga Reserve Management Plan 3rd ed. National Trust of South Australia, South Australia.

Manual Removal

Hand Pulling

Hand pulling may be the best method for scattered seedlings, soft plants without reproductive bulbs, annuals and small or shallow-rooted shrubs in soft soil. Hand pulling should only be used on plants which will not regrow from rootstock left behind in the soil.

Place one hand flat on the ground, stem between your fingers, and press down on the soil, this will minimise soil disturbance. Take hold of the plant at ground level with your other hand and pull out the weed.

For small woody plants such as young broom, boneseed, pittosporum and olive hold the stem at ground level gently rock the plant back and forth until it comes away cleanly. Placing your feet either side of the stem will help minimise soil disturbance.

For soft leafy plants with tap roots, push a trowel or knife into the soil next to the plant and move the blade to dislodge the tap root.

If any soil is disturbed, tramp it down and rake mulch over the slightly disturbed area to stop weeds re-establishing. Ensure all root matter is removed to avoid re-sprouting.

Hand Pulling is best done when the soil is moist. It is also better to hand pull weeds before seed heads develop. If the plant is seeding, cut off the seed heads or place a bag over them before you attempt removal to reduce the chance of spread.

Herbicides

Anyone undertaking any form of weed control using chemicals should be trained in the safe use of the chemical and appropriate safety equipment must be used.

Numerous herbicides are available from local hardware shops. Each herbicide has its advantages and disadvantages. It is important that the right herbicide is chosen, so that it is effective at killing the targeted weed species, while having minimal impact on non-target species.

Glyphosate can be a useful herbicide as it is:

• 
  generally less persistent in soil, although will persist in sand for several weeks;
  
• 
  less harmful to humans and animals;
  
• 
  easy to measure and use; and
  
• 
  relatively inexpensive.
  

The most significant disadvantage with Glyphosate is that it is non-selective, which means that it can potentially kill any plant that it comes into contact with. It is therefore not appropriate for widespread use, where native plant species are present. It is essential that correct training in bush regeneration be undertaken before Glyphosate is used amongst native vegetation.

Other herbicides

Other herbicides may be more selective but have other disadvantages. These may include:

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  Extended residual life within soils of up to two years. Some herbicides can move through soil, killing trees and shrubs some distance away
  
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  Measuring small quantities can be difficult, many are designed for broadacre usage
  
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  Toxicity of herbicide may require considerable safety equipment.
  

A surfactant needs to be used with herbicide, but penetrants must not be used as some practitioners have found this will also kill native grasses. Dye marker should be added to the spray unit. This is to ensure that weeds are not sprayed twice, to avoid off target damage and to increase personal safety levels.

The following weed management techniques rely on the effective use of herbicides. It is important to choose the correct method for different types of weeds and to ensure that the correct rate of herbicide is used.

When using herbicides, ALWAYS follow the instructions on the label.

Wiping Foliage

Wiping foliage with herbicide is a good method of applying chemicals directly to the target plant without damaging native vegetation. This works where there are isolated broadleaf weeds in relatively intact bushland. This method can also be used on plants with bulbs, tubers or corms.

Weedbrush

A Weedbrush is light and easy to carry and herbicide can be directly applied to foliage of individual weeds, with minimal risk of damage to non target plants.

Use a herbicide mixture of 4 parts clean water with 1 part concentrated Glyphosate and 2ml of dye marker per 100ml prepared mixture.

Tongs of Death

Another way to wipe herbicide onto targeted foliage is by using the “Tongs of Death”. These are particularly good for strappy or bulbous weeds. You can either buy this tool or make it yourself using stainless steel tea bag or kitchen tongs (depending on the size of the leaves) and attaching foam to the ends using twine. Use a squeeze bottle or equivalent to apply herbicide mixture to the foam and wipe tongs along the weed’s leaves.

Use a herbicide mixture of 5 parts clean water with 1 part concentrated Glyphosate (and 2ml of dye marker per 100ml prepared mixture).

Cut and Swab

Cut and swab is the preferred control method for woody weeds that are (1) likely to re-shoot from an untreated cut stump, (2) cannot be effectively hand-pulled (e.g. soil too dry or plant too big) or (3) where soil disturbance is to be minimised.

It is easiest to do this with two people, one to cut off the stem close to the ground and the other to apply the herbicide mixture. All stems must be removed. The herbicide needs to be applied immediately to all cut surfaces, otherwise its absorption and effectiveness is reduced. You can also rough up the sides of the remaining stem and swab with herbicide to increase its uptake.

Use a herbicide mixture of 5 parts clean water with 1 part concentrated Glyphosate (and 2ml of dye marker per 100ml prepared mixture) in a dabber bottle.

Disposal of Cut or Pulled Material

Weeds which have the potential to regenerate from cut material or which have fruits or flowers present should be bagged and removed from the site, to prevent the further spread of weeds.

Drill and Fill

Drill and Fill is good for a range of large woody weeds that have a base of 4cm in diameter or larger and has been used successfully on olive trees.

Holes are drilled or cut into the target tree and then filled with a suitable herbicide mixture.

The holes should be placed as low on the main stem as possible. For olives holes should be placed in the lignotuber (a swollen part of the root at or just below the soil surface). Use a drill bit approximately 10mm in diameter. Holes should be 1.5-4cm deep. Keep them as vertical as possible. Fill the hole immediately with herbicide mixture either with a brush, squeeze bottle or similar.

Repeat the process at intervals of 3cm around the entire base of the tree. You can not have too many. If you feel you don’t have enough holes drill some more. If there are exposed roots drill and fill them as well.

If drilling into the lignotuber, make sure you do not drill all the way through.

Drill holes in a ring around the lignotuber, with holes no more than 5cms apart and rings approximately 5cm below each other.

Another technique is to peel back the bark around stems, exposing the cambium layer all or most of the way around the stem and immediately apply herbicide mixture. For larger plants use a small axe, machete, chisel or similar to cut back the bark on all stems.

Fill each hole or cut as soon as you have drilled it, taking care that it is filled with liquid not froth.

A Glyphosate mixture of 5 parts clean water with 1 part Glyphosate (and 2ml of dye marker per 100ml prepared mixture) seems to work best.

The plant should start to drop its leaves within six weeks and cracking and blackening of the bark should occur within a few months. If the plant resprouts it will be necessary to repeat the process. It is essential that follow up control is done on any seedlings otherwise you may end up with a bigger infestation than you started with.

Kill rate for larger plants is greater using the drill and fill technique rather than cut and swab, as more of the herbicide gets into the growing tissue. The environmental benefit of the drill and fill technique is that habitat values are left in place; e.g. shelter sites, nesting sites or hollows.

Spray

Spraying with herbicide is often the most efficient method of removing herbaceous weeds but must be done with care and in the right conditions. Spraying must be done in the correct season when the plant is actively growing and should be avoided in windy conditions. It is often more effective with tall herbaceous plants, such as grasses, to first slash the area and spray only re-growth. This will also use less herbicide. When spraying, care needs to be taken to minimise off-target damage.

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  Follow manufacturer’s instructions;
  
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  Ideally herbicide should be dribbled onto weeds, taking care that run off does not occur minimising the chances of killing those ‘hard-to-see’ regenerating native plants and grasses which are the key to more rapid recovery;
  
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  Spraying should be done by someone with excellent plant identification skills to ensure non weed species are not accidentally targeted; and
  
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  Do not spray larger woody weeds in remnant vegetation;
  
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  Do not spray close to any delicate or threatened species;
  
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  Avoid spraying close to water bodies.
  

Safe use of herbicide

Irrespective of which herbicide is used, anyone who comes in contact with herbicides must read the label to ensure they are familiar with dosage rates and safety requirements. It should be noted that very little information is available on the long-term effects of any herbicide. Caution should always be used.

Great care needs to be taken as it is easy for off-target damage to occur. The spray unit requires very little pressure when spraying weeds in a bushland setting; weeds should not be sprayed to the point where herbicide run-off occurs.

5.7.Appendix G: Restoration of Grey Box Woodland Sites

Clarke et al (2010) identify 12 key steps in the restoration process:

1. 
   Define aspirational restoration goals and target species.
   
2. 
   Understand what healthy habitat looks like for the target species of interest and how the habitat may naturally change over time (e.g. disturbance cycles).
   
3. 
   Define a desired goal state (e.g. plant species composition and structure) for the habitat.
   
4. 
   Identify the current state and threats to the habitat in the landscape and site of interest (What desired elements are missing? What impact does each threat have?).
   
5. 
   Identify general restoration actions that can be undertaken to reach the desired state.
   
6. 
   Summarise actions in a draft implementation plan, prepare draft budget and work plan.
   
7. 
   Redefine specific, measurable, agreed-upon, realistic and timebound restoration goal(s) for the system after feasibility review and set achievable milestones.
   
8. 
   Develop an adaptive management plan if required (may further redefine goals).
   
9. 
   Implement the first phase of restoration actions.
   
10. 
    Monitor outputs and outcomes.
    
11. 
    Re-evaluate the situation, review assumptions about the system, revise goals / targets / milestones if needed.
    
12. 
    Implement other stages of restoration actions (if required) and manage the site(s) adaptively (as informed by monitoring results).
    

The management of Watiparinga Reserve is one of the best examples of adaptive management to achieve restoration goals. There are a number of key learnings from this restoration that would apply across all restoration sites. These have been adapted from Robertson EL (2010) and are reproduced below:

Be patient – degradation occurs over many years so restoring a more natural community will similarly take a long time.

Know what you are managing – investigate the site you wish to restore from the ground up. Knowing the soil type, aspect, what species are present and what the major threats are at any particular site are the things that will determine what actions will be needed to begin the regeneration of the natural community. The impact of surrounding land uses also needs to be taken into account. Housing or agricultural pursuits will require differing management strategies.

Use natural regeneration as the major restoration strategy – unless the area of Grey Box you are working in is severely depauperate of species, assisted regeneration is the most resource (time and money) efficient method of restoration.

Manage for what you want not what you don't want – knowing your site well will allow you to set up the conditions that allow natural regeneration without the need for extensive revegetation or ongoing weed issues.

Restore the openness of woodland midstorey – the invasion of woody weeds into areas of Grey Box has resulted in the loss of the open grassy nature of the natural system. The native fauna, particularly birds and reptiles, are adapted to life in the open structure of a grassy woodland and the closed canopy reduces their ability to access their resource requirements.

Restore the openness of woodland understorey – whilst the community is rich in understorey species the presence of areas of bare ground and leaf litter are an important component for many species.

Use minimum disturbance methods in all work – disturbed ground is ripe for invasion by weed species. Using minimum disturbance methods for weed removal gives the existing vegetation the best opportunity to recolonise and reduces the need for ongoing management.

Use local indigenous species in regeneration programs – there have been numerous instances over the years where revegetation programs have caused more problems than they have solved. Using local species will ensure they are adapted to the local environment, therefore requiring less ongoing management, and provide suitable resources for local fauna.

Use revegetation sparingly – only where the potential for natural regeneration has been severely compromised should revegetation be used. Natural regeneration generally gives greater success over the longer term.

Establish good records from the very beginning – it is vital to know the baseline from which you start and exactly what techniques have been used and when so that change can be measured and attributed to management. This gives the best understanding of processes and how techniques may be adapted to achieve set goals for a site.