|CALCATERRA, LUIS - South American Biological Control Lab(SABCL)|
|CABRERA, SONIA - Universidad De Buenos Aires|
|BRIANO, JUAN - South American Biological Control Lab(SABCL)|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2009
Publication Date: 1/1/2010
Citation: Calcaterra, L., Cuezzo, F., Cabrera, S., Briano, J. 2010. Ground Ant Diversity (Hymenoptera: Formicidae) in the Iberá Nature Reserve, the Largest Wetland of Argentina. Annals of the Entomological Society of America. 103(1): 71-83.
Interpretive Summary: The Iberá Natural Reserve (1,300,000 ha) located in Corrientes province, Argentina, preserves one of the largest freshwater wetlands of South America. The Reserve contains varied environments including grasslands, savannas, forests, lagoons and floating islands. It also includes fields for cattle, rice, and forestation. Because of the seasonal or permanent floods, water plays a fundamental role in the functioning of this ecosystem. Despite being a refuge for many plants and animals, only some mammals, birds and plants have been studied in Iberá, while other key groups as ants have been scarcely investigated. The ants are important components of the majority of the terrestrial ecosystems and play an important role in their functions. They are important for monitoring of ecosystems because of their abundance, response to environmental changes and relative easy identification. The knowledge of the ant fauna in representative environments of Iberá will permit the implementation of future conservation programs in this unique ecosystem. This study provides the first list of ants including 105 species occurring in extended and unmanaged environments of Iberá.
Technical Abstract: The Iberá Nature Reserve in northeastern Argentina protects one of the largest freshwater wetlands and reservoirs of species in South America. However, key invertebrate groups such as the ants (Hymenoptera: Formicidae) remain almost unknown. The main objective of this work was to study the ground ant diversity in four main habitats of Iberá: Grasslands, Savannas, Forests and Floating Islands. Pitfall traps were used to characterize ground foraging ant assemblages, compare ant diversity among environments, and establish habitat associations. We also used bait traps, manual collections, and Winkler and Berlese extractors on the ground, vegetation, and litter strata mainly to increase the species inventory. A total of 94 species in 30 genera were captured, being the highest number reported for a protected area of Argentina. The richest genus was Pheidole Westwood with 23 species including three species reported for the first time in Argentina. The most common species was Solenopsis invicta Buren. Overall, the Savanna was the richest and most diverse habitat with the highest number of exclusive species and functional groups. The Grassland showed the highest number of rare species, but only half of the expected species was captured. The Forest showed the lowest ant richness and diversity, but half of species were exclusive, promoting differentiation in species and functional composition. Generalized myrmicines were predominant and dominant in all habitats. Our findings indicate that habitat specialization could be an important factor determining the organization of ant assemblages in Iberá. The protection of each of these unique and threatened natural habitats of Argentina is needed to ensure the long-term preservation of their exclusive ant species.