Data from: Ant abundance in pitfall traps across different fire treatments

Fire is a dominant ecological force shaping many faunal communities
globally. Fire affects faunaeither directly, such as by killing
individuals, or indirectly, such as by modifying vegetation structure.
Vegetation structure itself also modulates fire frequency and intensity.
As such, faunal responses to fire need to be seen through the lens of
variable fire activity and vegetation structure. Here, we incorporate
information on fire activity and vegetation structure to enhance an
understanding of the response of ants to long-term (17-year) experimental
fire treatments in an extremely fire-prone tropical savanna in northern
Australia. A previous analysis revealed limited divergence in ant
communities after five years of experimental fire treatment. Hence, we
first investigated the extent to which ant communities diverged over a
subsequent 12 years of treatment. We then assessed the relative
contribution of fire treatment, cumulative fire intensity(fire activity)
and woody cover to responses of ant species frequency of occurrence,
richness and composition. We found that, even after 17 years, fire
treatments explained little variation in any ant response variable. In
contrast, woody cover was a strong predictor for all of them, while fire
activity was a moderate predictor for abundance and richness. Ant species
occurrence and richness increased in open habitats receiving higher levels
of fire activity, compared with plots with higher vegetation cover
experiencing low (or no) fire activity. Moreover, species composition
differed between plots with high and low vegetation cover. Our findings
provide experimental support to the principle that the effects of fire on
fauna are primarily indirect, via its effect on vegetation structure.
Furthermore, our results show that a ‘uniform’ fire regime does not have
uniform impacts on the ant fauna, because of variability imposed by
interactions between vegetation structure and fire activity. This helps
explain why there is often a weak relationship between pyrodiversity and
biodiversity, and it lessens the need for active management of
pyrodiversity to maintain biodiversity.