Influence of extrafloral nectary phenology on ant–plant mutualistic networks in a neotropical savanna

Abstract

Temporal variation has been one remarkable feature of ecological interactions. In ant–plant mutualism, this variation is widely known, although little is understood about the mechanisms that shape these variations. This study tested whether or not the phenology of extrafloral nectaries (EFNs) influences the temporal variation of two properties of an ant–plant interaction network. The network under investigation exhibited a nested pattern and low specialisation over most months. Monthly nestedness and specialisation in the network were negatively correlated, both being influenced by temporal variations in extrafloral nectar production of the plant community. The months of highest activity in the nectaries (August–November) were those when the level of generalisation in the network was at its highest. Although there were temporal variations in the properties of the network, the generalist core of the species remained the same over time. The stable core enhances the coevolutionary importance of ant–plant interactions for the community. Thus, it can be concluded that the phenology of EFNs is one effective mechanism shaping the temporal variation in ant–plant interaction.

Evidences that human disturbance simplify the ant fauna associated a Stachytarpheta glabra Cham. (Verbenaceae) compromising the benefits of ant-plant mutualism

“…However, investment of the plant in attracting ants can be influenced by the plant species, the phenology and ontogeny of the plant and EFNs and by external factors such as changes in climate and habitat (Lange et al, 2013;Oliveira and Freitas, 2004;Queiroz et al, 2013). In our study, S. glabra showed no induction or increased biotic defense (EFNs) and physical (sclerophylly) in response to environmental disturbance but still showed higher herbivory in the disturbed area.…”

“…The amount and identity of ant species visiting a plant myrmecophytic interaction is determined by the amount and quality of extrafloral nectar (Lange et al, 2013;Rico-Gray and Oliveira, 2007). However, investment of the plant in attracting ants can be influenced by the plant species, the phenology and ontogeny of the plant and EFNs and by external factors such as changes in climate and habitat (Lange et al, 2013;Oliveira and Freitas, 2004;Queiroz et al, 2013).…”

“…Studies with ant-plant interactions through ENFs in Cerrado show that C. crassus is the most common and abundant specie in ant-plant interactions involving extrafloral nectaries and exsudate-producer herbivores (Lange et al, 2013;Rico-Gray and Oliveira, 2007;Schoereder et al, 2010). Although B. heeri was present but presents no aggressiveness (Rico-Gray and Oliveira, 2007).…”

Positive Relation Between Abundance of Pericarpial Nectaries and Ant Richness in Tocoyena formosa (Rubiaceae)

“…Network analysis shows associations (links) between species (nodes) in a community, and is a commonly used approach in order to study how interactions are organized (Dáttilo et al, 2014;Blüthgen et al, 2015;Del-Claro et al, 2016). Several studies have been using this method for either community networks (Lange et al, 2013;Maruyama et al, 2014Maruyama et al, , 2015 or individual-based ones (Baker-Méio & Marquis, 2012;Gomez & Perfectti, 2012;Dáttilo et al, 2014). This analysis provides a great number of metrics and, for our aim, we selected six: complementary specialization (H2'), species specialization (d'), degree (k), specialization and 1 depicts a perfect specialization (Blüthgen et al, 2006;Dormann et al, 2009).…”

Wasps are better plant-guards than ants in the extrafloral nectaried shrub Ouratea spectabilis (Ochnaceae)

“…Pseudomyrmex gracilis forages in a diverse array of plants, regardless of the presence of other ants (Stefani et al, 2000;Santos & Del-Claro, 2001) and is pointed out as one common ant species in ant-plant ecological networks in Cerrado vegetation (Lange et al, 2013). Unfortunately, the natural history of this ant species is not well understood, most likely because of the low number of individuals found on plants compared to other ants (Rodrigues et al, 2008).…”