Patterns of diversity and abundance of fungus-growing ants (Formicidae: Attini) in areas of the Brazilian Cerrado

Abstract

Fungus-growing ants (tribe Attini) are characteristic elements of the New World fauna. However, there is little information on the patterns of diversity, abundance, and distribution of attine species in their native ecosystems, especially for the so-called "lower" genera of the tribe. A survey of attine ant nests (excluding Atta Fabricus, 1804 and Acromyrmex Mayr, 1865) was conducted in a variety of savanna and forest habitats of the Cerrado biome near Uberlândia, Brazil. In total, 314 nests from 21 species of nine genera were found. Trachymyrmex Forel, 1893 was the most diverse genus with 10 species. Eighteen species were found in the savannas, including Mycetagroicus cerradensis Brandão & Mayhé-Nunes, 2001, a species from a recently-described genus of Attini, whereas in the forests only 12 species were found. Forest and savannas support relatively distinct faunas, each with a number of unique species; the species present in the forest habitats did not represent a nested subset of the species found in the savannas. Furthermore, although many species were common to both types of vegetation, their abundances were quite different. The density of attine nests is relatively high at some sites, exceeding an estimated 4,000 nests per hectare. In this sense, attine ants can be regarded as prevalent invertebrate taxa in the Brazilian Cerrado.

Habitat diversity enhances ant diversity in a naturally heterogeneous Brazilian landscape

“…Several studies, including previous studies in the Cerrado, have already demonstrated that many ant species have strong habitat associations and that, as consequence, there is often a high degree of species turnover between different habitats (Bestelmeyer and Wiens 2001;Ribas et al 2003;Vasconcelos and Vilhena 2006;Ribas and Schoereder 2007;Vasconcelos et al 2008). However, very few studies have assessed the relative contribution of alpha and beta diversity to regional ant diversity (gamma diversity) (but see Dahms et al 2010;Paknia and Pfeiffer 2011).…”

“…Previous studies in the Cerrado suggest that it supports a highly diverse ant fauna (Silva et al 2004;Lopes and Vasconcelos 2008), including poorly known, rare, and endemic species (Brandão et al 2001;Vasconcelos et al 2008;Solomon et al 2011). These studies also indicate a high degree of species turnover among habitats, especially among major plant physiognomies (Vasconcelos and Vilhena 2006;Lopes and Vasconcelos 2008;Vasconcelos et al 2008). Therefore, it may well be possible that local variations in vegetation cover could promote an increase in ant diversity at higher scales as also predicted by the mosaic concept (Whittaker and Levin 1977).…”

Anthropogenic effects on interaction outcomes: examples from insect-microbial symbioses in forest and savanna ecosystems

“…As habitats are altered due to logging, clearing for agriculture, or climate change, such alterations are likely to induce changes in ant species composition (cf. Vasconcelos et al 2008) impacting ant species diversity through either species composition changes and/or species loss.…”

The Potential Role of Scattered Trees for Ant Conservation in an Agriculturally Dominated Neotropical Landscape

“…We focused our study on ants because they are highly abundant in tropical ecosystems, play many ecological roles (including the control of populations of other insects), and are responsive to various types of land clearance and conversion across a wide range of habitats (Underwood & Fisher 2006). Furthermore, previous studies in the Cerrado have revealed a highly diverse ant fauna (Silva et al 2004, Lopes & Vasconcelos 2008, which includes poorly known, rare, and endemic species (Brandão et al 2001, Vasconcelos et al 2008a, Solomon et al 2011.…”