Project title: Assessing impacts of varying fire and weed management approaches on native species diversity, weed cover and fuel loads in an urban Banksia woodland.
Dates: 2014 - long term
Funding: Botanic Gardens and Parks Authority
- fire ecology, fire interval and fire hazard
- prescribed burning
- grass-fire cycle
- weed management
- bushland risk management
- fuel accumulation
- Banksia woodland
- biodiversity protection
This project focuses on the impact of different fire and weed management activities on the persistence of native plant species in Kings Park and Bold Park. It also examines the effect of weed management on fuel loads and fire risk, and the effect of fire management on weed cover. The study involves application of a combination of weed management and fire (fuel) management techniques in six adjacent blocks within a single experimental site in each of Kings Park and Bold Park. Each treatment block is about 1.5 hectares in size.
Two treatment blocks will have no fire; two will be treated with managed fire at short intervals (5-6 years) and two at medium intervals (~12 years). The two blocks within these fire management treatments will receive contrasting weed management: no management, or application of BGPA’s standard weed management approach. Pre-fire survey in each of these sites assessed fuels loads, canopy openness and the richness, density and structure of the plant community (native species and weeds). These surveys will be repeated at annual intervals for the duration of the experiment, which is anticipated to be long term.
Controlled fires were successfully undertaken in Kings Park in May 2015 and Bold Park in April 2016 as part of this project. Since these fires, BGPA scientists have been tracking changes in the ecosystem as a result of the fire and subsequent management treatments. Surveys looking at the re-emergence of seedlings, re-sprouting of affected plants and weed prevalence have begun. Other indicators such as soil moisture and the structure of plants and tree canopies are also being surveyed seasonally. Weed management in early winter is underway in three of the six experimental blocks.
To increase replication and study power, it is also hoped that other Banksia woodland managers in the Perth area will join the study and replicate the treatments and survey design over the coming years. The research program was expanded to include a third site at Jandakot Regional Park in September 2015, where a team from DPaW, Canning Council and the BGPA implemented a replicate pre-fire survey and burn.
Additional studies are also underway in the fire area, examining the impact of fire on trapdoor spider populations, fungi and the water repellence of soils.
Our key objectives are to:
- Assess the impacts of managed fire at short and medium intervals on native species richness and composition in two urban Banksia woodlands
- Assess the development of fuel loads and fire hazard following managed fire
- Assess the role of grassy weeds in the development of fuel loads and fire hazard
- Assess the role of fire in enhancing or suppressing grass (and other) weed species
- Assess the effectiveness of the combination of fire and weed management of weed cover
- Identify management combinations that optimise native species persistence while minimising fire hazard and weed spread in Banksia woodlands in the presence of grassy weed species.
Secondary objectives are to:
- Assess canopy temperatures during managed fire in Banksia woodlands
- Assess soil temperature and moisture patterns before, during and after fire
- Assess changes in key habitat attributes – canopy openness, bare ground, nectar production and vegetation structure before and after managed fire in Banksia woodlands
- Assess changes in soil hydrophobicity and infiltration before and after managed fire in Banksia woodlands
Dr Ben Miller, Dr Allison O'Donnell, Kings Park and Bold Park bushland management teams
Dr Shane Turner, Dr Carole Elliott, Dr David Roberts, Dr Miriam Muñoz-Rojas, Dr David Merritt, Prof Kingsley Dixon, Mr Ryan Tangney
Ryan Tangney (PhD; Curtin 2015 - current) Does varying season and intensity of fire lead to different seed fates in wildfire and managed fire? Supervisors: Dr Ben Miller, Dr David Merritt, Prof Kingsley Dixon.
Russell Miller (PhD; Murdoch 2015 - current) Tolerable fire intervals of native Banksia woodland plant species. Supervisors: Dr Ben Miller, Dr David Merritt, Prof Neal Enright, Dr Joseph Fontaine.