A Cross Biome Synthesis on Pollination Systems in a Megadiverse Tropical Country

Abstract

The diversity of plant-pollinator relationships is crucial in terrestrial ecosystems. Despite the extensive literature on pollination, research is still skewed towards temperate regions, specific plant lineages and pollinator groups, leading to biogeographic and taxonomic biases. We systematically reviewed the diversity of plant-pollinator interactions in Brazil to illustrate the cross biome distribution of pollination systems, research patterns and knowledge gaps. We characterised biome-dependent diversity of pollination systems and functional specialisation. A total of 5,280 records of plant-pollinator interactions, 119 plant families, 1,193 plant and 1,499 pollinator species were found. Bees comprised the highest number of interactions, followed by hummingbirds. Fabaceae, Asteraceae, Rubiaceae and Melastomataceae interacted with > 50% of pollinator species. The Atlantic Forest included 54% of the studies, while the Pantanal showed the highest proportion of plant families, of those found in the biome, studied. Nevertheless, many of the richest plant families within biomes were under-sampled. A biome-pollinator group network revealed a significant relationship of pollinator functional groups with biomes. Brazil comprises a great diversity of pollination interactions, with bees as most studied and important pollinators of native plants. Plant families with highest diversity of interactions are species rich, and in most cases, were also associated with different pollinator functional groups. The detected functional specialisation reflects both the diversity of pollination systems found in the tropics and research preferences. Finally, the research biases we detected, including lack of precise description on the role of floral visitors, can steer future research on pollination studies in a megadiverse, mostly tropical country to increase our understanding of plant-pollinator interactions at the global scale.