Beyond buzz-pollination – departures from an adaptive plateau lead to new pollination syndromes

Agnes S. Dellinger, Marion Chartier, Diana Fernández-Fernández, Darin S. Penneys, Marcela Alvear, Frank Almeda, Fabián A. Michelangeli, Yannick Staedler, W. Scott Armbruster, Jürg Schönenberger

Pollination syndromes describe recurring adaptation to selection imposed by distinct pollinators. We tested for pollination syndromes in Merianieae (Melastomataceae), which contain bee‐ (buzz‐), hummingbird‐, flowerpiercer‐, passerine‐, bat‐ and rodent‐pollinated species. Further, we explored trait changes correlated with the repeated shifts away from buzz‐pollination, which represents an ‘adaptive plateau’ in Melastomataceae.
We used random forest analyses to identify key traits associated with the different pollinators of 19 Merianieae species and estimated the pollination syndromes of 42 more species. We employed morphospace analyses to compare the morphological diversity (disparity) among syndromes.
We identified three pollination syndromes (‘buzz‐bee’, ‘mixed‐vertebrate’ and ‘passerine’), characterized by different pollen expulsion mechanisms and reward types, but not by traditional syndrome characters. Further, we found that ‘efficiency’ rather than ‘attraction’ traits were important for syndrome circumscription. Contrary to syndrome theory, our study supports the pooling of different pollinators (hummingbirds, bats, rodents and flowerpiercers) into the ‘mixed‐vertebrate’ syndrome, and we found that disparity was highest in the ‘buzz‐bee’ syndrome.
We conclude that the highly adaptive buzz‐pollination system may have prevented shifts towards classical pollination syndromes, but provided the starting point for the evolution of a novel set of distinct syndromes, all having retained multifunctional stamens that provide pollen expulsion, reward and attraction.

Department of Botany and Biodiversity Research
External organisation(s)
Herbario Nacional del Ecuador, University of North Carolina at Wilmington, California Academy of Sciences, Institute of Systematic Botany, The New York Botanical Garden, University of Portsmouth, University of Alaska, Fairbanks
New Phytologist
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
106042 Systematic botany, 106008 Botany, 106012 Evolutionary research
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