Prescribed patch burnings increase thrips species richness and body size in grassland communities

Prescribed patch burning is a well-known tool for grassland and savanna management that has been recognised as a suitable strategy to enhance biodiversity at landscape-level scales. Nevertheless, effective monitoring of the biota responses to fire is an essential step towards biodiversity conservation. We investigated fire effects on thrips communities (Thysanoptera) - a group of minute and diverse insect in grasslands. We performed a replicated small-scale fire experiment in South Brazilian Campos, and tested for fire effects on total abundance, species richness of different feeding guilds (e.g. leaf, flower and fungal feeders) and thrips species body size in the short (1month) and long-term (1year). We found positive fire effects on leaf herbivore richness in recently burned patches where the resprouted vegetation had enhanced nutritional quality, and also later on following the diversification of plant communities. The richness of fungivorous thrips was also benefited by resource heterogeneity in burned patches 1year after fire. A positive fire effect on thrips community body size was also found at this time, possibly indicating that larger species had an advantage in dispersal to the spatially distributed burned patches across the unburned grassland matrix. Effects on total abundances were not detected. Our study emphasises the role of prescribed patch burnings in producing high quality resource-rich habitat spots for Thysanoptera communities at local scales.