Bushfire recovery
NRM NEWS - MARCH 2020
By Shanna Rogers
Senior Land Services Officer
Recovery following intense bushfire may be a long process. In some instances, the environment may never be the same as it was before the fire. However, there are various activities land managers can do to assist in the recovery of natural environments following a bushfire.
Erosion
Erosion risk increases after a fire due to the lack of groundcover to stabilise the soil and slow down the speed of runoff. Intense burns may also cause soils to repel rather than absorb water, leading to increased runoff and erosion.
Some activities to reduce the risk of erosion and promote the recovery of land include:
- Remove grazing pressure
- Minimise soil disturbance by reducing vehicle traffic over the burnt land
- Slow the flow of water by using sediment traps such as logs, smaller branches, mulch, hay bales, coir logs, etc.
- Encourage natural regeneration of native vegetation and pasture
- Prioritise works to protect the most valuable assets first.
Dams & watercourses
Threats
- Runoff from the burnt sloping ground will carry debris, ash and soil into dams and waterways, fouling the water and making it unsuitable for stock and wildlife
- High sediment loads reduce oxygen levels in the water. Sediments can suffocate aquatic animals with a fine layer of silt which coat their gills and other breathing structures.
Short-term actions (what you can do now)
- Protect dams and watercourses from runoff after a fire using sediment traps to filter runoff. Small hay bales pegged down with droppers, or chicken wire anchored across the drainage line or coir logs can be effective
Long-term actions
- Revegetation along waterways will help buffer temperature extremes and sediment loads entering streams.
Weeds
The risk of weed invasion increases after a fire.
Although fire can promote weed growth, it can also provide access to weed infestations. Try to control post-fire germinated weeds before they set seed. Prioritise weed removal to areas where long-lasting weeds are threatening valuable sites and areas of established weeds.
Disturbed areas after a bushfire are particularly vulnerable to weed incursions. Ensure that vehicles and equipment used by contractors and advisors are clean and weed-free.
Ensure fodder is weed-free. Feed-out in a confined area away from drainage lines to reduce the likelihood of weeds being spread.
Building up stock numbers when recovering from a fire is an activity that can introduce weeds. Quarantine new stock in a containment area or paddock to allow weed seed to pass through the animal. Check for weed seed in fleece and continue to check for weeds in areas with new stock.
Pest Animals
The months after a bushfire are among the best times to control feral animals.
Fox, wild dog and cat control may be vital to protect animals that survived the bushfire.
Control of rabbits, hares, goats, deer, feral horses will help reduce grazing pressure on regenerating plants.
Rabbits warrens and fox dens may be exposed. There is an opportunity to clean up warrens and dens with debris and damaged fences.
Wildlife Habitat
Only remove burnt material that is a health and safety hazard, such as dead trees that could fall and threaten people’s safety, buildings or fence lines.
Leave any fallen timber where it falls in remnant areas. Fallen wood is the natural way fauna habitat is created and is an essential refuge for wildlife post-fire. Burnt trash and undisturbed ash beds also offer some protection from wind and water erosion following fires and provide better conditions for germination and early regrowth.
In some cases, it may be helpful to provide artificial shelter such as nest boxes for birds and mammals, tin sheets and tiles for reptiles, and chicken wire and shade-cloth shelters for ground-dwelling animals and birds to give them a safe habitat from invasive predators (such as foxes and cats) and nesting areas.
Native vegetation regeneration & revegetation
Usually, the best option is to leave native vegetation to regenerate naturally.
Priority should be given to sensitive weed control to encourage natural regeneration, taking care to prevent any off-target damage to native plants.
Assess the total loss or recovery of native vegetation in spring-summer following the fire. In certain circumstances, supplementary planting with tubestock or direct seeding with native seed can be useful.
Regeneration of revegetation plantings largely depends on the age of the planting and species. Where immature plants have burnt, replanting may be necessary.