Ant functional diversity in temperate-zone forests: a comparison with Neotropical ants

Background/Question/Methods

Recent studies illustrate the importance of a functional-trait approach to the development of more quantitative and predictive models to explain community assembly rules. Ant functional diversity will be examined at eastern North American and Neotropical sites along environmental gradients in order to compare the morphological space in temperate-zone and tropical ants. Patterns of functional diversity across tropical and temperate faunas will be examined, enabling the description of how functional morphology of ants in temperate-zone forests compares and contrasts with ant functional morphology in the tropics. In temperate forests, ant assemblages were sampled using pitfall traps in 67 sites spanning ten degrees of latitude across the northeastern United States. In tropical forests, we surveyed 26 Atlantic forest localities, representing 3,000 km of tropical rainforest along twenty degrees of latitude in eastern Brazil. A morphological data set comprising linear morphometric measures of collected species was obtained for each latitudinal gradient. We selected 15 morphological characters as surrogate to diet and foraging habits. Several approaches will be combined to measure the functional diversity of ants, regarding the functional diversity indexes and morphological analyses (trait-convergence and trait-divergence assembly patterns). Finally, a comparative trait-based analysis between temperate and tropical leaf-litter ant fauna will be investigated to compare morphospace occupation.

Results/Conclusions

We recorded 550 ant species from leaf-litter samples in the Brazilian Atlantic Forest and 92 ant species in northeastern United States forests. We measured approximately 2,000 specimens from Neotropical forests and 580 specimens from temperate forests to quantify morphological diversity. The patterns derived from the comparative analysis will be used to describe morphospace occupation and ant community assembly in temperate-zone and Neotropical forests. Furthermore, our findings should contribute to the understanding of morphological patterns along geographic gradients.