Few studies have sought to understand the vertical patterns of bat–fruit systems, and therefore, it is not possible to evaluate whether interpretations based on data collected from a single stratum adequately represent the interaction patterns of this system. In this context, we evaluated the dissimilarity in the assemblage of frugivorous bats, plants, and their interactions within seed dispersal networks across three forest strata in the Atlantic Forest of southern Brazil. To construct the networks, we collected fecal samples from bats captured using mist nets in three strata (understory, sub‐canopy and canopy). The canopy network presented a smaller size, fewer interactions, and lower connectance (C), higher specialization (H2'), and modularity (Qw) compared to the sub‐canopy and understory networks. Meanwhile, the understory network showed a larger size, a greater number of interactions, asymmetry, and nestedness (WNODF) when compared to the canopy and sub‐canopy. The unified networks between two and three strata presented greater asymmetry and intermediate values of connectance (C), specialization (H 2 '), modularity (Qw) and nesting (WNODF) compared to the others. For species‐level metrics, plant specialization varied between strata. For beta diversity of interactions, all comparisons between networks showed high dissimilarity of species and interactions between strata. However, comparisons between higher strata showed lower dissimilarity when compared to the lower stratum. Our results indicate that sampling restricted to the understory represents only a fraction of the species and interactions in the bat‐fruit system and, therefore, may influence knowledge about interactions and the degree of species specialization in networks. Therefore, to comprehensively detect and quantify bat–fruit interactions in tropical regions, as well as reveal the processes underlying these interactions, future studies should consider the vertical structure of forests.
Supi et al. (Sun,) studied this question.