Edge-induced narrowing of dietary diversity in leaf-cutting ants.
Bull Entomol Res
; 101(3): 305-11, 2011 Jun.
Article
em En
| MEDLINE
| ID: mdl-21034522
Much of the ecological alteration faced by human-modified Neotropical forests can be assigned to edge effects, including the proliferation of some voracious herbivores such as leaf-cutting ants. However, the underlying mechanisms/impacts of tropical forest edge on herbivores performance and their foraging behaviour (e.g. dietary diversity) have rarely been investigated. The goal of this study was, therefore, to determine whether and how the annual diet (i.e. species richness, diversity and the relative proportion of pioneer versus non-pioneer species of plant materials) of Atta cephalotes colonies differs in the forest edge versus the interior zone of a large remnant of Atlantic forest in northeastern Brazil. Among the key results was a strong habitat effect on dietary diversity (explaining ca. 40-50% of the variation), which, in edge colonies, decreased approximately by one fourth compared to interior colonies (inverse of Simpson's index: 3.7±0.84 versus 4.99±0.95). There was a predominance of leaf fragments collected from pioneer species in the diet in both habitat (86% in edge and 80.4% in interior). Edge colonies collected proportionally more fragments from pioneer species than colonies located in the forest interior. Our results are the first to demonstrate an edge-mediated relaxation of dietary restrictions in leaf-cutting ants. These findings render robust support to previous evidence indicating the reduction of bottom-up forces as a key factor explaining both edge-induced hyper-abundance and increased herbivory of leaf-cutting ants in human-modified Neotropical landscapes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Formigas
/
Ecossistema
/
Folhas de Planta
/
Dieta
/
Comportamento Alimentar
Tipo de estudo:
Prognostic_studies
Limite:
Animals
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Bull Entomol Res
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido