What is Assisted Regeneration?
Assisted regeneration is the removal of obstacles to natural regeneration. It is based on a method of bush regeneration developed in Sydney during the 1960’s and 1970’s by sisters Eileen and Joan Bradley.
The Bradley Method is based on three founding principles:
- Work from good to bad Work begins in less infested, and thus more resilient areas, and proceeds into more heavily infested areas. This means a core of ‘good’ bush is protected and expanded out into surrounding areas.
- Minimise disturbance The Bradley sisters were opposed to activities that would disturb topsoil and leaf litter. Their method included stockpiling and replacing soil and leaf litter with horizons intact whenever excavations were necessary.
- Allow the bush to set the pace This means that the speed of regeneration dictates the pace of work. If an area is cleared of weeds too quickly, the result may be a second infestation of weeds before regeneration can occur. Conversely, proceeding too slowly can prevent regeneration from taking hold in areas of established weed infestations.
Modern bush regeneration continues to follow the principles of the Bradley Method, with some modifications as our understanding of the ecology increases. Each area of bushland has its own unique set of conditions, and the method of restoration must be adjusted to suit each specific site.
When is it used?
The level of degradation determines the level of action required to restore a natural area. Sites with little or no degradation can often be left to natural regeneration as long as conditions remain stable. At the other end of the spectrum, highly degraded sites can require reconstruction of environmental or biological elements, or even fabrication of an entirely new environment. Between these two extremes lie the conditions where assisted regeneration is most appropriate.
Disturbance and Resilience
It is important to understand the relationship between disturbance and resilience when restoring natural areas. A disturbance is any event that brings about changes to an ecosystem. A disturbance can be a short, one-time event (such as a landslide or a storm) or experienced continuously over long periods (such as stormwater run-off from urban areas or weed infestations). Disturbances can be natural occurrences (like bushfires or digging of soil by animals) and they can be caused by human activity (such as land clearing or diversion of drainage lines).
Resilience is the capacity of an area of bushland to absorb disturbance and maintain its integrity as a functional ecosystem. Many Australian ecosystems have evolved with resilience to regular disturbances such as bushfires and flood/drought cycles. Every community has a level of disturbance that can be tolerated, beyond which irreversible damage is incurred. The aim of assisted regeneration is to keep the level of disturbance within a range suited to the natural community’s resilience.
Bush-it and Assisted Regeneration
Bush-it specialises in assisted regeneration. Our highly qualified team is focussed on using their knowledge of Australian plants to increase the resilience of bushland we work in. For over ten years, Bush-it has worked in bushland in and around Sydney. Our experience includes work on sites ranging from low levels of disturbance through to highly degraded areas requiring reconstruction and revegetation. Through our work and external training courses, our staff continue to develop a sound knowledge and understanding of the ecosystems we work in.