Variation in fire interval sequences has minimal effects on species richness and composition in fire-prone landscapes of south-west Western Australia

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Ecology and Biodiversity
TitleVariation in fire interval sequences has minimal effects on species richness and composition in fire-prone landscapes of south-west Western Australia
Publication TypeJournal Article
Year of Publication2011
AuthorsWittkuhn, R, McCaw, LW, Wills, AJ, Robinson, R, Andersen, AN, Van Heurck, P, Farr, J, Liddelow, G, Cranfield, R
JournalForest Ecology and Management
Date Published01/2011
AbstractPrescribed burning is used in many fire-prone ecosystems for wildfire mitigation and conservation of biodiversity. However, there is limited information about how biota responds to long-term fire management, especially at a whole-of-community level. We studied community responses to different fire interval sequences resulting from planned and unplanned fires in Mediterranean-climate ecosystems in the Warren bioregion of south-west Western Australia (SWA) to determine the resilience of the biota to contrasting fire regimes. Fire history data were used to identify contrasting fire interval sequences in forest and shrubland communities for the period 1972–2004. We surveyed vascular plants, ants, beetles, vertebrates and macrofungi at 30 sites to investigate community-level responses to consecutive short (SS: ≤5 years), consecutive long (LL: ≥10 years), one very long (VL: 30 years), or mixed/moderate (M: 6–9 years) fire interval(s). All sites had a common time-since-fire of not, vert, similar4 years at the commencement of sampling which was conducted over two years. Species richness and composition differed between forest and shrubland communities, but the influence of fire interval sequences on taxonomic groups was minimal and difficult to detect. There was weak evidence of compositional differences between SS and LL/VL regimes for plants, ants, beetles and macrofungi but no difference between these regimes and the intermediate disturbance M-regime. These results demonstrate the resilience of the biota in open forests and shrublands of SWA to contrasting fire interval sequences over the past 30 years. We conclude that occasional short (3–5 years) intervals between fires are unlikely to have a persistent effect on community composition, though maintaining a regime of short or long intervals may alter species composition and/or abundance. We suggest that variability in fire intervals is important for long-term conservation of the biota. For the Warren Region, prescribed burning at an intermediate level of disturbance and incorporating variability in interval length is recommended to achieve the dual objectives of wildfire mitigation and biodiversity conservation.
Short TitleForest Ecology and Management
Refereed DesignationRefereed