Abstract
Epiphytic vascular plants comprise an essential part of the tropical flora and are a key component for ecosystem functioning. Some recent studies have used a network approach to investigate the interaction of epiphytes with host phorophytes at the community level. However, knowledge on commensalistic epiphyte–phorophyte network structure still lags behind with regard to other biotic interaction networks. Our goal was to provide a more complete overall perspective on commensalistic epiphyte–phorophyte interaction and its placement with respect to other better studied mutualistic interactions. We hypothesized that the intensity of the fitness effect of the different types of biotic interactions would determine the degree of specialization of the interacting organisms. Thus, commensalistic epiphyte–phorophyte interactions would have lower specialization than mutualistic interactions. We compiled and analysed the structural properties (nestedness, network specialization and modularity) of 12 commensalistic epiphyte–phorophyte networks and compared them with the same metrics to 11 ant–myrmecophyte, 86 pollination and 13 seed dispersal mutualistic networks. Epiphyte–phorophyte networks were nested and modular with regard to the corresponding null models and had greater nestedness than mutualistic networks, whereas specialization and modularity were significantly lower. Commensalistic epiphyte–phorophyte networks of interactions are both nested and modular, and hence, are structured in a similar way to most other types of networks that involve co-evolutionary interactions. Nevertheless, the nature and intensity of the ecological processes involved in the generation of these patterns is likely to differ. The lower values of modularity in commensalistic epiphyte–phorophyte networks are probably due to the low levels of specialization and the lack of co-evolutionary processes between the interacting partners.
Highlights
The establishment of biotic interactions is a topic of great interest in ecology
Specialization and modularity were significantly lower in the epiphyte–phorophyte networks than in the rest of the networks (Figs 1 and 2, all tests: P < 0.016), whereas nestedness was significantly higher (Fig. 2, P < 0.02)
We evaluated the network structure of 12 epiphyte–phorophyte networks and compared it to those found in ant–myrmecophyte, pollination and seed dispersal mutualistic networks
Summary
These interactions can be described as networks in which each species is connected to one or more different species (Bascompte et al 2003; Bascompte and Jordano 2014). The network structure has relevant implications for the coexistence and stability of species and has been described as the architecture of biodiversity (Bascompte and Jordano 2007). The topological properties of these networks provide information on community organization and offer a general framework to evaluate the different types of interactions between species (Proulx et al 2005; Blick and Burns 2009; Bascompte and Jordano 2014). Several types of mutualistic (Bascompte et al 2003; Bascompte and Jordano 2007; Bascompte 2009; Vázquez et al 2009; Fortuna et al 2010; Pastor and Garca 2015) and antagonistic networks (Cagnolo et al 2011; Hagen et al 2012; Elias et al 2013; Morris et al 2014) have been extensively studied contributing to an understanding of the factors influencing the structure of these networks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
