TL;DR: Temperature, rainfall, soil organic matter content, altitude and abundance of vegetation seem to be the major drivers structuring beetle assemblages and influencing species abundance and richness.
Abstract: The family Carabidae is an important group of mostly terrestrial predators in the order of Coleoptera. Their diversity and assemblage structure were analyzed using samples obtained from six localities in northern Tunisia using pitfall traps. Species richness and abundance of carabids in different habitat types (forests, parks and cultivated fields), and their relationship with the environment were discussed. A total of 840 carabid beetles belonging to 39 species were collected. An analysis of site similarity based on species richness showed spatial variation. The Shannon-Wiener diversity and evenness indexes were calculated. The most abundant taxa were Chlaenius chrysocephalus (Rossi, 1790), Carterus rotundicollis (Rambur, 1842) and Amara aenea (De Geer, 1774). Non-metric multidimensional scaling (NMDS) ordination highlighted the faunistic affinities among sites revealing three main groups. Temperature, rainfall, soil organic matter content, altitude and abundance of vegetation seem to be the m...