Open access journal: http://periodicos.uefs.br/ojs/index.php/sociobiology ISSN: 0361-6525 DOI: 10.13102/sociobiology.v61i1.9-20 Sociobiology 61(1): 9-20 (March, 2014) Composiion and Diversity of Ant Species into Leaf Liter of Two Fragments of a Semi- Deciduous Seasonal Forest in the Atlanic Forest Biome in Barra do Choça, Bahia, Brazil Freitas, JMS 1,2,3 , Delabie, JHC 1,2 & Lacau, S 1,2,3 Introduction Ants (Hymenoptera: Formicidae) form one of the most diverse and ecologically important insect groups in terms of their diverse and essential functions in terrestrial ecosystems (Wilson & Hölldobler, 1990; Alonso & Agosti, 2000). Their predominance can be attributed in part to their eusocial nature, which favors their dispersal and successful occupation of new habitats (Wilson & Hölldobler, 2005). Since the Cretaceous period, these animals have demonstrated successful radiation throughout almost all terrestrial habitats, with numerical and biomass predominance in most of them (Fernández & Ospina, 2003; Wilson & Hölldobler, 2005). Ant diversity in forest ecosystems is particularly high in the leaf litter (Alonso & Agosti, 2000; Silva & Brandão, 2010), although community composition is inluenced by nu- merous factors, including the nature of the surrounding plant formations, soil composition and the local microclimate Abstract We present here the results of a study of leaf liter ant diversity in remnant areas of semi-deciduous seasonal forests in the Atlanic Forest biome. Standardized collecions were made in 2011, using pifall traps and Winkler sacks in two fragments of naive forest in the municipality of Barra do Choça in the micro-region of the Planalto da Conquista, in southwestern of the state of Bahia, Brazil. A total of 107 species from 37 ant genera and 9 subfamilies was collected. The observed richness was high, and the diversity indices (Shannon-Wiener) of the two fragments suggest that in spite of being strongly impacted by anthropogenic acions, they maintained high faunal diversity levels, similar to those observed in other original Atlanic Forest sites in state of Bahia. Analyses of the spe- cies accumulaion curves (Jackknife 2), however, indicated that survey efort was not suicient to capture all of the species present. The high observed numbers of unique species, the shape of the species accumulaion curves, and high values of esimated richness suggest that the survey areas were quite heterogeneous. These results provide new informaion concerning regional biodiversity that will be useful for coninuing studies on fragmentaion processes in the region. Sociobiology An international journal on social insects 1 - Universidade Estadual de Santa Cruz, Ilhéus-BA, Brazil. 2 - Laboratório de Mirmecologia, CEPLAC/CEPEC/SECEN, Ilhéus-BA, Brazil. 3 - Universidade Estadual do Sudoeste da Bahia, Itapeinga-BA, Brazil. Aricle History Edited by: Gilberto M M Santos, UEFS, Brazil Received 05 November 2013 Iniial acceptance 13 December 2013 Final acceptance 14 January 2014 Keywords Formicidae, Planalto da Conquista, Atlanic Forest, Tropical forest Corresponding author Juliana Marins da Silva Freitas Univ. Estadual do Sudoeste da Bahia Laboratório de Biossistemáica Animal Itapeinga-BA, Brazil E-mail:julliana.marins@yahoo.com.br (Schowalter & Sabin, 1991). Ant community structures re- spond directly and quickly to both quantitative and qualita- tive environmental changes, and have therefore been the focus of stu-dies investigating the effects of environmental distur- bances on ecological communities (Veiga-Ferreira et al., 2005; Delabie et al., 2006, 2007). Ants maintain numerous biotic associations with other organisms in their environments (Wilson & Hölldobler, 1990; Rico-Gray & Oliveira, 2007), rapidly respond to habitat alter- ations such as fragmentation (Peck et al., 1998; Veiga-Ferreira et al., 2005; Delabie et al., 2006) and are relatively easily col- lected and identiied (Peck et al., 1998), making them ideal models for studying and monitoring global biodiversity and useful as bioindicators of disturbances caused by ecosystem size reductions The Atlantic Forest biome has been a focal area for environmental conservation efforts (Dean, 2002). Studies of Atlantic Forest biodiversity have almost exclusively fo- RESEARCH ARTICLE - ANTS