No evidence of a common pattern of taxon or phylogenetic diversity across elevation for beetle (Coleoptera) families

Abstract Mountains are among the most diverse terrestrial habitats on Earth, and understanding how montane species are distributed is a first step towards predicting how these taxa will respond to changing thermal environmental conditions. While most reported patterns of diversity and elevation are negative or hump‐shaped relationships, syntheses of these patterns are mostly derived from vertebrates. Here, we explored over 270 studies from the literature (more than a third of which we could reanalyse their data) to test whether beetles (Coleoptera) displayed a uniform pattern predicted by these syntheses at the family level. We found that deriving a common diversity/elevation pattern for beetles was not possible as our search results contained a tremendous taxonomic bias towards two families out of 176 (ground beetles (Carabidae) and dung beetles (Scarabaeidae)), and for most families, we found no reported investigation of elevation and diversity. We also found that the two most diverse families of beetles (Staphylinidae and Curculionidae) were severely underrepresented in our data set. Within the two better‐sampled families, we examined the diversity/elevation relationship using two measures of diversity: taxonomic and phylogenetic. For each family, we found no common trend of diversity across elevation. In both phylogenetic diversity and genus richness, the Scarabaeidae showed a strong negative relationship with elevation, while the Carabidae showed a much weaker negative relationship (mainly due to intrafamilial variation in the patterns observed). We conclude that a generalised pattern of diversity and elevation for beetles is not yet possible given that (1) most known patterns are from only two families, (2) patterns within those families are not the same and (3) that the most diverse beetle families are relatively understudied.