Plant-insect interactions and ecosystem services in the context of global change

More than 90% of tropical plant species are dependent on animal-pollination, making the disruption of pollination services one of the greatest threats to tropical biodiversity. Deforestation for pastoral expansion may interact synergistically with climate change to impact fundamental plant-pollinator interactions and density-dependent plant gene flow processes. In this study, we quantified the population spatial and genetic structure, reproductive success, pollen dispersal patterns, pollinator community composition, and pollinator fidelity of a common understory tree, Miconia affinis, across Central Panama over two years, one of which occurred during a typical year (2013) and the other during the El Niño Southern Oscillation (ENSO, 2016). We found that pollinator community composition was significantly different between the ENSO and non-ENSO years and that pollinators in the ENSO year exhibited significantly lower and more variable pollen fidelity. Pollen fidelity correlated positively with seed set, but only in the non-ENSO year, indicating that extreme climate could disrupt classic relationships between pollinator foraging fidelity and plant reproductive success. Our models also revealed that local kinship negatively impacted seed set, with a significantly larger negative effect on seed set during ENSO. Additionally, we found that pollen dispersal distances were greater for trees with higher kinship neighborhoods, suggesting that self-incompatibility may be promoting genotypically distinct and spatially distant seed sires. By incorporating genetic and landscape data into the quantification of plant reproductive success, we highlight the critical role that pollen fidelity and landscape genetic diversity play in the resilience of tropical plant populations to deforestation and extreme climate events.