Assessing the impact of fire on spiders through a global comparative analysiss

Abstract

Fire is an important ecological disturbance; however, in many regions fire regimes are changing due to anthropogenic factors. Understanding the responses of species and ecosystem to fire can help to develop predictive models and inform fire management decisions. Despite their massive diversity and abundance, relatively little is known about the impacts of fire on invertebrates. Spiders are a diverse and ubiquitous group, with variation in ecological, behavioural and life history traits, and can offer important insights into the impacts of fire on invertebrates and whether these depend on environmental factors, phylogenetic history, or species traits. We conducted phylogenetic comparative analyses of published data from studies investigating the impacts of fire on spiders. We investigated whether fire affects family level abundance and whether this effect depends on ecologically relevant traits or site-specific factors (vegetation, latitude, fire type, time since fire). We found that time since fire had a significant effect on the abundance of some spider families (Lycosidae, Linyphiidae, Agelenidae), and within forest vegetation types. There was no relationship between family level traits and response to fire, suggesting that a trait-based approach does not increase predictive power in this group at this taxonomic level. Overall, it is difficult to make broad generalisations about the impacts of fire on spider abundance due to variation in site- and fire-specific factors. We did, however, find evidence that short fire intervals may be a threat to some spider families, and in forest ecosystems, where abundance initially decreased after fire, which may have important implications for fire management strategies. Finally, we show that analyses of published data can be used to detect broad scale ecological patterns and provide an alternative to traditional meta-analytical approaches.

Assessing the impact of fire on spiders through a global comparative analysis

“…The datasets and code used during the current study are available from the Dryad Digital Repository: https://dx.doi. org/10.5061/dryad.m63xsj46s [83]; https://datadryad.org/stash/ share/mlITztEX47D-t7kIg20vS9E6tR36VPx684SgMfy3YMY.…”