Bush regeneration and weed control

regeneration involves carrying out works (such as weed

removal, stormwater management, fire management, feral

animal control, revegetation, nutrient management, track

management) in degraded areas of bushland to reverse or

minimise degrading impacts and allow natural regeneration

and on-site perpetuation of local species to occur. Bush

regeneration is typically associated with urban and urban

fringe bushland, small-scale rural projects, mine rehabilitation

or the maintenance of public reserves, transport corridors

and walking tracks.

There are many reasons why native bushland becomes

degraded. Some of these include:

• clearing for urban development, service corridors,

expansion of agricultural areas

• runoff from stormwater and agriculture carrying nutrients

and other contaminants

• concentrated stormwater discharge from pipes and roads

which scours drainage lines

• disturbances (including changes to soil, water, light, fire

regimes) to ecosystems which allow non-native species

to successfully invade.

The aims of bush regeneration projects vary depending

on the site and objectives of the landowner and/or users.

These can include one or more of the following:

• restoring or creating a suitable habitat to either attract

or maintain native flora and fauna

• creating food supply or transport corridors for native fauna

• maintaining an ecological community that provides

ecological or aesthetic services or enhances historical

features

• minimising or preventing soil erosion and stabilising

drainage lines

• removing weeds and modifying native plant communities

to tolerate changes in soil, water and light levels

• reversing historical anthropogenic damage to ecosystems.

There are many strategies used to successfully regenerate

bushland. The first documented method was developed by

the Bradley sisters in 1971. They adopted a philosophy of

controlled weeding without replanting. This technique has

gradually been modified to include activities other than the

removal of weeds such as:

• selecting the type of native plants which will be retained

after natural regeneration

• replanting native species lost from the bush or no longer

germinating naturally

• planting native species better suited to the particular area

• reversing biophysical factors that result in ecosystem

degradation.

The amount of weeding, seed collection, planting and

stabilisation will vary depending on the site and objectives.

A bush regeneration project can take up to (and sometimes

more than) 10 years to complete. In some cases it is better

not to start a bush regeneration project unless there is

guaranteed funding for at least five years. Short term projects

should have a maintenance period of at least two years.

Comprehensive site assessment and project planning prior to

starting a bush regeneration project is therefore crucial and

are fundamental to successful project management.

Weeds can be classified into three distinct classes based on

the level of threat they pose to an ecosystem.

1. Ecosystem transformers that can dominate and destroy

native vegetation communities within 10 years

2. Invasive weeds that are highly mobile within a native

vegetation community but do not have the immediate

potential to alter it in the short to medium term

3. Naturalisers that reside mainly on the edge of the native

vegetation communities and have little potential to be

either ecosystem transformers or highly invasive.

The class, density and distribution of weeds will determine

the effect on the environment. This may include:

• competing with the local native plants for space, sunlight,

moisture and nutrients

• inhibiting the germination of native plants

• altering the habitat of local terrestrial and aquatic flora

and fauna

• changing the fire regime

• modifying the soil characteristics

• favouring the establishment of other weed species.