Increasing prevalence of severe fires change the structure of arthropod communities: Evidence from a meta-analysis

1. Animal ecology and evolution are shaped by environmental perturbations,
which are undergoing unprecedented alterations due to climate change. Fire
is one such perturbation that causes significant disruption by causing
mortality and altering habitats and resources for animals. Fire regimes
are changing on a global scale, but the effects of these changes on animal
communities are poorly understood. Arthropods are one of the most
ubiquitous and diverse animal taxa on the planet and their populations are
sensitive to environmental change. Given their wide-ranging impacts on
ecosystem functioning, a better understanding of arthropod responses to
changing fire regimes is critical and may also provide more general
insights into how other groups might respond to fire. 2. Here, we provide
a comprehensive meta-analytical assessment of how fire influences the
arthropod community across habitats and functional groups. Using data from
130 peer-reviewed papers across the globe, we tested how a variety of fire
characteristics, including management regime, severity, and
time-since-fire affect arthropod populations and communities across
habitats. 3. Our results show that arthropod communities display
substantial variation in response to fire and that community-level
responses are most likely to be detected within the first year. Responses
also vary depending on fire characteristics and habitat. Specifically,
while community metrics such as diversity were increased by low severity
fires, they were reduced by high severity fires. Likewise, evenness
increased after prescribed burns but was reduced after wildfire. Measures
of arthropod community structure decreased following fires in deserts and
forests. 4. Across the entire arthropod community, fire also had variable
effects on community diversity. Fire tended to have a negative effect size
on arthropods across life stages, but responses did vary among groups.
Nearly all functional groups exhibited a negative response to fire with
the exception of herbivores, for which abundance, diversity, and richness
increased after fire. 5. Our results suggest that the increasing
prevalence of high-severity wildfires is changing the structure of
arthropod communities. Given their ubiquitous presence and diverse roles
in terrestrial ecosystems, these community changes are likely to affect
ecosystem functioning in various ways, including through increased
herbivory.