The Interplay of Fire and Vertical Strata Shaping Herbivorous Insect Communities in Altimontane Forest Islands

This is the authors' abstract. We don't add key points for this paper.

Understanding how fire and vertical stratification interact to shape insect communities is essential in increasingly fire‐prone montane systems. We investigated how herbivorous insect communities vary across vertical strata (canopy and understory) and fire incidence in 14 altitudinal forest islands within the Espinhaço Range, Brazil. Using data collected in 4 years spanning a 7‐year period (2014–2020), we analyzed the temporal variation of species richness and abundance, and changes in species composition, gains and losses. Despite greater environmental exposure, canopy communities showed lower temporal variation in richness and abundance than those of the understory, suggesting a buffering effect likely driven by consistent resource availability and host‐plant specialization. Fire was not associated with changes in species composition nor species gains, but reduced species losses, particularly in the understory, possibly by favoring generalist species with broad ecological tolerance. Species gains were higher in the canopy, indicating that it may act as a recipient layer for dispersers from the surrounding campo rupestre matrix. Our findings highlight complex, stratum‐specific fire effects and suggest that post‐disturbance recovery may promote greater differentiation and stability of herbivorous insect communities across forest strata in montane ecosystems.