Epiphytic bromeliads as key components for maintenance of ant diversity and ant–bromeliad interactions in agroforestry system canopies Wesley D. DaRocha a,c,⇑ , Frederico S. Neves a , Wesley Dáttilo b , Jacques H.C. Delabie c a Laboratório de Ecologia de Insetos, Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil b Red de Ecoetología, Instituto de Ecología A.C., Xalapa, Veracruz 91070, Mexico c Laboratório de Mirmecologia UESC/CEPLAC, Centro de Pesquisa do Cacau, C.P. 7, 45600-900 Itabuna, BA, Brazil article info Article history: Received 30 January 2016 Received in revised form 5 April 2016 Accepted 6 April 2016 Keywords: Tropical forests Ecological networks Beta diversity Tank bromeliads Formicidae abstract Cocoa is produced in a wide range of land use systems, with the traditional shaded systems in Bahia (Brazil) as the most forest-like and biodiverse. The aim of this study was to evaluate the role of different cocoa agroforestry systems (AFSs) in maintaining community structure and interactions between ants and epiphytic bromeliads. The study was conducted at four sites in the cocoa producing region of the southeastern of the state of Bahia, Brazil, and comprised a native forest and three different cocoa AFSs. We found a total of 103 ant species associated with epiphytic bromeliads, with 83% of the species occur- ring in native forest canopy bromeliads also occurring in cocoa AFSs. The Cocoa Cabruca System (CAB) and the Rustic-Planted Shade System (RPS) had ant community structural components of biodiversity similar to those found in the native forest environment. The alpha and gamma diversity of ants found in Monospecific-Shaded Cocoa Agroforestry System (MCA) associated with Erythrina spp. shade trees were significantly different from the diversity found in the other AFSs and native forest. The presence of epiphytic bromeliads, regardless of the system and scale, maintained ant diversity in agroforestry sys- tem canopies similar to that of native forest. Using metrics derived from graph theory, we found a high level of specialization regarding ant–bromeliad interactions in native forest, with a gradual decrease in specialization with environmental homogenization. Agroforestry systems thus represent an important strategy for maintaining the structure of canopy-associated ant communities by enabling the establish- ment of numerous bromeliad species, thus contributing to the maintenance of ant diversity and services in a mosaic landscape AFSs and native forest. Ó 2016 Elsevier B.V. All rights reserved. 1. Introduction Agroforestry systems (AFSs) have emerged as a good strategy for maintaining natural forest biodiversity while taking into account the economic needs of producers (Bhagwat et al., 2008; Falcão et al., 2015; Schroth et al., 2004; Steffan-Dewenter et al., 2007). Within this context, cocoa (Theobroma cacao L., Malvaceae) AFSs have been particularly successful in some tropical regions due to the exceptional potential of these systems to reconcile economic needs with conservation of biodiversity (Schroth et al., 2011, 2015). Cocoa AFSs are characterized by replacement of the original forest understory with cocoa crop, while maintaining or establishing a fraction of the canopy as shade for crops (Rice and Greenberg, 2000; Ruf and Schroth, 2004). Vascular epiphytes are among the plant types found in the canopy (Cruz-Angón and Greenberg, 2005; Hietz, 2005; Hylander and Nemomissa, 2008; Souza et al., 2015). Consisting mainly of bromeliads, cacti, ferns, and orchids, vascular epiphytes make up about 10% of the world’s flora (Gentry and Dodson, 1987), with most species being typical of for- est canopies (Benzing, 1995; Nieder et al., 2001). Tropical agro- forestry canopies can have high structural complexity, including because of the frequent occurrence of epiphytes in tree crowns (Cruz-Angón and Greenberg, 2005; Hietz, 2005; Moffett, 2013). It follows that, since epiphytes increase microhabitat diversity in the agroforestry canopy, they play an important ecological role in community structure, and in the maintenance of diversity of ants and other arthropods that use epiphytes for foraging or nesting substrate (DaRocha et al., 2015; Rodgers and Kitching, 2011; Stuntz et al., 2003; Yanoviak et al., 2004). http://dx.doi.org/10.1016/j.foreco.2016.04.011 0378-1127/Ó 2016 Elsevier B.V. All rights reserved. ⇑ Corresponding author at: Laboratório de Ecologia de Insetos, Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil. E-mail address: wd.darocha@gmail.com (W.D. DaRocha). Forest Ecology and Management 372 (2016) 128–136 Contents lists available at ScienceDirect Forest Ecology and Management journal homepage: www.elsevier.com/locate/foreco