2.1. Networks studied
To evaluate our hypotheses, we built a dataset compiling data from
empirical ant-plant networks available in published studies and
representing interactions between ants and plants with EFNs in different
communities worldwide (ant-plant networks hereafter). For that, we
searched published studies at Science Direct, Web of Science platforms
(Core library) and Google Scholar using the following key terms:“ant-plant network” (results without replicates: Science Direct
= 16; Web of Science = 50; Google Scholar = 121) and
“ant-extrafloral nectar network” (results: Science Direct = 67;
Web of Science = 0; Google Scholar = 13). After this search, one of us
(BM) read the title and abstract of all papers, checking if the studies
reported ant-plant networks based on interactions observed in the field.
We did not consider papers reporting networks in which the ant-plant
interactions were experimentally manipulated (N = 1). After this first
screening, we gathered 32 potentially suitable papers describing
empirical ant-plant networks. Some of those papers investigated
different questions using the same ecological networks. In such cases,
we selected the oldest study from which we could extract the network’s
information. Then, at the end of this first screening process, we
gathered 22 papers suitable to our study.