Morphological patterns and community organization in leaf‐litter ant assemblages

Abstract

We present a new approach to determine the number and composition of guilds, using the hyperdiverse leaf-litter ant fauna as a model, based on appropriate morphological variables and species co-occurrence null models to describe the complex assemblages of interacting species community structure at the 1-m 2 scale. We obtained 18 linear morphometric measures from 949 workers of 171 leaf-litter ant species (18 762 measurements) surveyed in four Atlantic Forest localities to test whether the assemblages are morphologically structured; the morphological characters were selected to indicate diet and foraging habits. Principal components analysis was used to characterize the morphospace and to describe the guild structure (number of species and composition). The guild proportionality assembly rule (significant tendency toward constant proportion of species in guilds) was assessed at the 1-m 2 scale. Our analysis indicates that the division of leaf-litter ants into guilds is based mainly on microhabitat distribution in the leaf-litter, body size and shape, eye size, and phylogeny. The same guild scheme applied to four more sites shows that different Atlantic Forest areas have the same leaf-litter ant guilds. The guild proportionality assembly rule was confirmed for most guilds, suggesting that there are guild-specific limitations on species coexistence within assemblages; on the other hand, in a few cases the variance in guild proportion was greater than expected under the null assumptions. Other studies on ant functional group classification are partially supported by our quantitative morphological analysis. Our results, however, imply that there are more compartments than indicated in previous models, particularly among cryptic species (confined to soil and litter) and tropical climate specialists. We argue that a general null model for the analysis of species association based on morphology can reveal objectively defined groups and may thus contribute to a robust theory to explain community structure in general and have important consequences on studies of litter ant community ecology in particular.

Diversidade e riqueza de formigas (Hymenoptera: Formicidae) em remanescentes de Mata Atlântica na Bacia Hidrográfica do Alto Tietê, SP

“…Os resultados aqui apresentados indicam que a riqueza de formigas de serapilheira é semelhante a outros remanescentes de Floresta Ombrófila Densa que pertencem à Serra do Mar: Estação Ecológica de Boracéia (94 espécies) (Yamamoto 1999); Núcleo Juréia (73 espécies) (Tavares 2002), Núcleo Cubatão (69 espécies) (Tavares 2002), Núcleo Cunha (79 espécies) (Tavares 2002); Parque Estadual Carlos Botelho (110 espécies) (Silva & Brandão 2010) e Parque das Neblinas, que é uma Reserva Privada do Patrimônio Natural (87 espécies) (Suguituru et al 2011). A comparação do número de espécies é diretamente possível, pois, em todos os remanescentes, as coletas foram efetuadas usando o mesmo protocolo.…”

“…Além disso, muitos estudos mostram o papel de Formicidae como bioindicadores, por serem sensíveis às mudanças que ocorrem no ambiente (Majer 1983, Andersen & Majer 2004, Stephens & Wagner 2006, Majer et al 2007, Pais & Varanda 2010. Nas florestas tropicais até 50% da fauna de formigas podem estar associados à serapilheira (Delabie & Fowler 1995), onde apresentam altos níveis de diversidade taxonômica, morfológica e funcional (Kaspari 1996, Ward 2000, Silva & Brandão 2010 …”

Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities

“…These data were obtained from local studies involving ant fauna surveys conducted in several regions of the state (Lopes & Fowler 2000;Silva & Silvestre 2000, 2004Lutinski & Garcia 2005;Schmidt et al 2005;Lutinski 2008;Rosumek et al 2008;Iop et al 2009;Cardoso & Cristiano 2010;Silva & Brandão 2010).…”

Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept

“…The pioneers of this kind of study in ants are mainly Andersen (1991Andersen ( , 1992Andersen ( , 1997, in Australia, while in Brazil, the first studies making references to the guild or functional group of Formicidae was Delabie et al (2000) in the Atlantic Forest and Silvestre et al (2003) in the "cerrado" biome. More recent publications referred to ant guilds in Brazil are those of Brandão et al (2009) and Silva & Brandão (2010).…”