Nutritional traits as drivers of plant-pollinator interactions : evolutionary origins, ecological prediction, and network-level insights

Abstract

This thesis investigates how nutritional floral traits shape plant-pollinator interaction networks across evolutionary and ecological scales. Using phylogenetic analyses of 414 plant species, I show that nectar sugar composition is primarily driven by evolutionary history, paleoclimate, and floral morphology rather than contemporary pollinator diets. Analyses of plant-bee interaction networks further demonstrate that nutritional traits, particularly nectar sugar and pollen characteristics, improve predictions of interaction probabilities beyond classical abundance- and morphology-based models. Finally, I develop a bias-corrected network framework revealing that landscape structure strongly influences network specialization and nestedness, while weather effects are partly driven by observation bias. Together, these findings identify nutritional trait matching as a key mechanism structuring plant-pollinator networks under environmental change.