Changes in carabid species distribution, body traits and associated microbiota along an elevational gradient

Global warming is affecting alpine habitats through a temperature increase above the global average. Such rapid environmental change can affect biotic interactions, impacting ecosystem stability and functionality; however, these processes in mountain regions are not well understood. We used an elevation gradient ranging from 1,000 to 2,500 m a.s.l. as a proxy for climate change to examine the diversity of carabid beetle species, body traits and their individual microbiota. On 12 grazed pasture sites (3 replicate sites every 500 m of altitude), we installed and checked pitfall traps for 24 hours every two weeks throughout the growing season. Almost 6,000 individuals were morphologically identified to species, and body length, wing development, sex and trophic status were noted. Additionally, 182 carabid beetles were captured by hand, and used for microbial community analysis. Community composition, diversity, and the ratio between winged and wingless species of carabid beetles changed significantly, but non-linearly with elevation. Carabids established individual-specific but still elevation-dependent patterns in prokaryotic and fungal communities. Prokaryotic communities were similar below 2,000 m but changed at higher elevations and fungal diversity was highest at 2,000 m. Such data will help us understand how global warming is affecting biotic interactions in soil.