Ant taxonomic and functional beta-diversity

The decomposition of beta-diversity (β-diversity) into
its replacement (βrepl) and richness (βrich) components
in combination with a taxonomic and functional approach, may help to
identify processes driving community composition along environmental
gradients. We aimed to understand which abiotic and spatial
variables influence ant β-diversity and identify which processes may drive
ant β-diversity patterns in Mediterranean drylands by
measuring the percentage of variation in ant taxonomic and functional
β-diversity explained by local environmental, regional climatic and
spatial variables. We found that taxonomic and functional replacement
(βrepl) primarily drove patterns in overall β-diversity
(βtot). Variation partitioning analysis showed that respectively
16.8 %, 12.9 % and 21.6 % of taxonomic βtot, βrepl and
βrich variation were mainly explained by local environmental
variables. Local environmental variables were also the main determinants
of functional β-diversity, explaining 20.4 %, 17.9 % and 23.2 % of βtot,
βrepl and βrich variation respectively. Findings suggest
that niche-based processes drive changes in ant β-diversity, as local
environmental variables may act as environmental filters on species and
trait composition. While we found that local environmental variables were
important predictors of ant β-diversity, further analysis should address
the contribution of other mechanisms, e.g. competitive exclusion and
resource partitioning, on ant β-diversity.