I’ve had a lot of success using fire to manage weeds with a focus on the interface when establishing and maintaining bush fire asset protection zones and preparing Hazard Reduction burns. There are broad benefits in managing these areas using an integrated, land management focus rather than purely ‘fuel’ management however regular and well-times maintenance is required which can be difficult with competing priorities for many land managers.
With previous experience working in local government, some Councils have more flexibility in managing sites requiring intensive weed control with the opportunity to focus substantial time on heavily weed infested sites. In many cases this involved creating large numbers of pile/windrows for burning which promoted a flush of weed growth that could be treated prior to setting seed (we created & burnt ~250 piles per year). Ongoing maintenance focusing on hand-weeding created great results which even the bush regeneration teams used visit and assess. Unfortunately this is more difficult to achieve for other agencies with limited field staff and funding linked closely to bush fire mitigation. The use of contractors can also create difficulties with works having a definite start and end date and follow-up works limited to available funding in the following financial year.
Organisations that allocate suitable funding for minor maintenance enhance opportunities to undertake follow-up works throughout the year which results in significant savings for future maintenance and progressive improvements on the biodiversity of sites. Engaging contractors more consistently also increases efficiencies as the teams have a greater link with the sites and are able to plan and quote for works with a longer-term focus. Obviously not every site requires this level of integrated management as heavily disturbed sites in gentle terrain can be merely slashed – the more integrated works are best implemented on sites with difficult terrain or close to riparian or drainage areas.
While I have been managing sites in this way for over 10 years in the Hornsby/Ku-ring-gai area, in the last 3 years I have been able to implement works in Sutherland with a focus on control of intensive weeds plumes containing established species such as Privet and Lantana in interface areas for establishing APZ’s and prior to Hazard Reduction burns. Some sites have had as many as 40 piles created adjacent to a few as 8-12 houses which the RFS burn prior to the HR burn and additional follow-up weed control undertaken by contractors. This type of work ensures the weed infested areas are actually treated, as in many cases large weed plumes do not burn in the conditions that HR’s are undertaken, but are likely to burn in wildfire conditions. In addition the weed plumes are likely to invade the adjacent bushland following a HR burn, extending the area they cover and the future problems of trying to manage them as fuel.
While I have always struggled to find the time and resources to monitor sites where I have used fire for weed management, I have always taken pre and post works photos and can easily illustrate the success where follow-up works have been achieved. The greatest challenge is managing funding and illustrating the long-term benefits (environmental and financial) of a more integrated approach to fuel management.