Vascular epiphytes and host trees of ant-gardens in an anthropic landscape in southeastern Mexico

Abstract

Ant-gardens (AGs) are considered one of the most complex mutualist systems between ants and plants, since interactions involving dispersal, protection, and nutrition occur simultaneously in them; however, little is known about the effects of the transformation of ecosystems on their diversity and interactions. In five environments with different land use within an anthropic landscape in southeastern Mexico, we investigated the diversity and composition of epiphytes and host trees of AGs built by Azteca gnava. A total of 10,871 individuals of 26 epiphytic species, associating with 859 AGs located in 161 host trees, were recorded. The diversity and composition of epiphytes tended to be different between environments; however, Aechmea tillandsioides and Codonanthe uleana were the most important species and considered true AG epiphytes, because they were the most frequent, abundant, and occurred exclusively in AGs. Other important species were the orchids Epidendrum flexuosum, Coryanthes picturata, and Epidendrum pachyrachis, and should also be considered true AG epiphytes, because they occurred almost exclusively in the AGs. The AG abundance in agroforestry plantations was similar or even greater than in riparian vegetation (natural habitat). The AGs were registered in 37 host species but were more frequent in Mangifera indica and Citrus sinensis. We conclude that true epiphytes of A. gnava AGs persist in different environments and host trees, and even these AGs could proliferate in agroforestry plantations of anthropic landscapes.

Spatial structure of ant‐gardens: vertical distribution on host trees and succession/segregation of associated vascular epiphytes

“…flexuosum rarely grows outside the A. gnava AGs (Morales‐Linares et al. ). Thus, our results suggest that the formation process of the AGs proposed by Catling () does not occur in the AGs studied.…”

“…In each plot we studied AGs constructed by Azteca gnava Forel (Formicidae: Dolichoderinae) ants (Morales‐Linares et al. ).…”

“…It is noteworthy that 528 trees (with and without AGs) have been recorded in these sampling plots (Morales‐Linares et al. ). All AGs on all host trees were recorded.…”

“…The abundance of AGs in forest gaps, riparian vegetation, disturbed sites and some agroforestry plantations has been related to the identity and physical characteristics of the host tree species as well as to the resources that trees offer to ants via their extrafloral nectaries or associations with Homoptera (Davidson ; Yu ; Catling , ; Marini‐Filho ; Morales‐Linares et al. ). The AGs provide nutrient‐rich substrates for epiphytic plants (Blüthgen et al.…”

Beyond the gardens: The extended mutualism from ant‐garden ants to nectary‐bearing plants growing in Amazon tree‐fall gaps

“…However, there are other types of more specialized associations where the plants have structures that permit the maintenance of an entire ant colony (Bronstein et al., 2006), minimizing behavioral variation among ant species, such as the forage period. A rather peculiar type of ant–plant interactions is the "Ant Gardens" (thereafter the AGs) which are known for the tropical regions of East Asia, and Central and South America (Davidson et al., 1990; Orivel & Leroy, 2011; Blüthgen et al., 2001; Kaufmann, Weissflog, Hashim & Maschwitz, 2001; Kaufmann & Maschwitz, 2006; Vicente et al., 2014; Morales‐Linares et al., 2016). They can be roughly defined as aggregates of epiphytes assembled by ants, but in fact, are sophisticated ant–plant mutualistic associations involving both protective and dispersal mutualisms, and myrmecotrophy (reviewed in Orivel & Leroy, 2011).…”