Mechanisms of species coexistence and functional diversity of ant assemblages in forest and pasture habitats in southwestern Brazilian Amazon

Andressa Silvana Oliveira De Menezes,Fernando Augusto Schmidt

doi:10.13102/sociobiology.v67i1.4552

Andressa Silvana Oliveira De Menezes, Fernando Augusto Schmidt

Open Access

https://doi.org/10.13102/sociobiology.v67i1.4552

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Journal: Sociobiology	Publication Date: Apr 18, 2020
Citations: 7	License type: cc-by

Affiliation: Universidade Federal do Acre

Abstract

In this study, we investigated the mechanisms behind species coexistence and the relationships between functional diversity and species richness in ant assemblages in both forest and pasture habitats in the southwestern Brazilian Amazon. We addressed the specific question: What is the primary mechanism for species coexistence in forest and pasture habitats? According to the identified mechanism in each habitat, we had the following alternative expectations: (i) niche partitioning – we expected to observe a linear positive relationship between functional diversity and species richness, indicating a complementary relationship; or (ii) niche filtering – a positive constant asymptotic relation between functional diversity and species richness, indicating a functional redundancy relationship. In total, we sampled 91 ant species, 82 species in a forest habitat and 16, in a pasture habitat. In the forest habitat we identified niche filtering as the structuring mechanism of the ant assemblage, but we were unable to identify a clear mechanism in the pasture habitat. Although the relationship between functional diversity and species richness was positive in both habitats, the relationship was weaker in the forest habitat, indicating a greater functional redundancy among the ant species in this habitat. Our results reinforce the divergence of species coexistence mechanisms and ant assemblage structures in both natural and human-modified habitats in the Southwestern Brazilian Amazon.

Highlights

Niche partitioning has often been used to explain ant species coexistence as well as ant community assemblages (Blüthgen & Feldhaar, 2010; Camarota et al, 2016)
Recent studies have suggested that niche filtering is the mechanism responsible for the coexistence of species in ant assemblages (Arnan et al, 2011; Fowler et al, 2013)
We addressed the main question: What is the primary mechanism for species coexistence in forest and pasture habitats? According to the mechanism identified for each habitat, we had the following alternative expectations: (i) niche partitioning – we expected to observe a positive and linear relationship between functional diversity and the species richness, indicating a complementarity relationship; or (ii) niche filtering - an asymptotic relationship between functional diversity and species richness, indicating a functional redundant relationship

Summary

Introduction

Niche partitioning has often been used to explain ant species coexistence as well as ant community assemblages (Blüthgen & Feldhaar, 2010; Camarota et al, 2016). The high number of ant species at the local scale (e.g., 86 species in 0.13 ha in northwestern Australia and 30 species in 1 m2 of leaf litter in Atlantic Forest, Brazil) (Andersen, 1983; Silva & Brandão, 2010) has led ant ecologists to question the role of interspecific competition in ant species coexistence and propose alternative mechanisms for community ant assemblages (Ribas & Schoereder, 2002; Cerdá et al, 2013). Ant species could overcome the negative effects of interspecific competition In this way, recent studies have suggested that niche filtering (similarities regarding the use of the resource) is the mechanism responsible for the coexistence of species in ant assemblages (Arnan et al, 2011; Fowler et al, 2013)

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Discussion

Conclusion