I’m currently working my way through 162 invertebrate samples from 27 sites in the Otway Ranges with the aim of understanding the effect fire has on flying insect population structure in Australia. Existing Australian studies on fire and insects have primarily focused on terrestrial and litter dwelling invertebrates, which may have a different response to fire than their flying counterparts. Studies that include flying insects have been conducted overseas in forests where the vegetation structure is very different to that of Australian forests.
Right now I’m working through all of the beetle samples, the order in which we collected the highest number of individuals. My results will hopefully add to our knowledge of the current global pollinator decline, and aid future research on the recovery of insectivorous animals after fire. All the disruption from coronavirus has really slowed things down for me but I’ve finally gotten my hands on my insects again and can carry on while I work from home.
As a research group, we've given a disproportionate level of attention to furry animals over the past few years, but Emma Window is helping redress the balance with her study of the effects of fire on flying insects. Given that she's been unable to visit the lab under coronavirus, she's got the lab to come to her!
A holy grail for ecological fire management and research: What aspects of the fire regime make plants and animals tick?
Growth-stage optimisation determines the proportions of vegetation growth stages (categorical representations of time since fire) that maximise species diversity, providing an operational goal for fire managers. To date, optimisation has only been applied to growth stages in a fire management context but other aspects of fire regimes, such as severity, are also likely to influence species diversity.
In our new paper, we ask:
1 How do growth stage and fire severity influence plant and vertebrate species’ occurrence?
2 What mix of growth stages and fire severities maximises the diversity of these groups?
We surveyed birds, mammals and plants in the tall wet forest of Victoria’s Central Highlands, and found that growth stage predicted the occurrence of many species. Severity of the most recent fire was important over and above growth stage for a small subset of species; however, low-severity fire was a more important driver of species diversity than any other growth stage or severity category.
Growth stage is a good surrogate for developing conservation targets in tall wet forests, but does not capture the full range of species’ fire responses. More complex versions of growth stage optimisation that accommodate multiple fire-regime variables need to be explored to yield ecologically meaningful conservation goals.
Swan, M., Sitters, H., Cawson, J., Duff, T., Wibisono, Y. & York, A. (2018). Fire planning for multispecies conservation: Integrating growth stage and fire severity. Forest Ecology and Management 415-416: 85-97
The results of our new paper, available as an Ecological Applications Preprint, suggest that use of patchy fire to break up large expanses of mature vegetation may enhance ecosystem function.
We studied the responses of bird functional diversity to TSF and two direct measures of environmental variation. Six bird functional traits (body mass, clutch size, food type, foraging behaviour, foraging location and nest form) were used to calculate functional diversity.
Functional richness was negatively related to TSF, suggesting that recent prescribed fire creates patchy vegetation and provides greater opportunities for species to partition resources. Buff-rumped Thornbill and Superb Fairy-wren were among the seven species more common in young vegetation than old, and all seven species build dome-shaped nests. This nest type offers better camouflage and shelter against predation than more open nests, but we lack a definitive explanation as to why dome-shaped nest-builders prefer younger vegetation.
We suggest that controlled use of patchy prescribed fire to break up large expanses of mature vegetation is likely to help sustain functional diversity.
Fire Ecology and Biodiversity at UniMelb
Bushfire Behaviour and Management at UniMelb
Quantitative & Applied Ecology Group at UniMelb
Integrated Forest Ecosystem Research at UniMelb