Shade coffee plantations favor specialization, decrease robustness and increase foraging in hummingbird-plant networks

Abstract

Agroforestry systems, such as shade coffee plantations, favor the maintenance of woody vegetation, which promotes the presence of pollinators such as hummingbirds. Many shade coffee plantations in Mesoamerica have been abandoned due to the fall in coffee prices and undergone succession processes that increase vegetation complexity. Alternatively, they have been replaced by cattle pastures, which negatively affect hummingbird-plant interactions. Here, we describe the structure of hummingbird-plant interaction networks in three types of land use―late-successional forests, coffee plantations, and cattle pastures―that were derived from a cloud forest in southern Mexico. For one year (2019–2020), we collected bimonthly quantitative data on hummingbird-plant interactions for each type of land use. We found that the network of each land use had a heterogeneous structure, and most species had few linkages. The late forests and coffee plantations had more species, pairs of interactions, and modularity than the cattle pastures. The cattle pasture network had the greatest robustness due to the presence of generalist hummingbirds, which are important for network cohesion in a great disturbance scenario. Furthermore, hummingbird visits were influenced by plant traits, such as foliage height diversity. The study findings suggest that the conversion of natural habitats have implications for the conservation of plant-pollinator interactions and that generalist pollinator species are key to disturbance resiliency.