Timing is Everything: An Overview of Phenological Changes to Plants and Their Pollinators

Plant-pollinator interactions are a critical component of a healthy plant community and a healthy ecosystem. However, these interactions are at risk due to many factors, including potential phenological mismatches that may disrupt the timing of successful pollination. Environmental variables influence both when plants flower and when insects pollinate, and if those variables change, so might the timing of each species. If those changes do not track each other, plants and pollinators may not be active at the same time, potentially causing substantial problems to both groups. Yet, there is little consensus thus far about how the timing of plants and pollinators has been changing and how that might ultimately influence this important ecological interaction. Here, we review the evidence for phenological shifts in both species and find that there is evidence of change, but that it is extremely species-specific with some species advancing their activities, some delaying, and some staying about the same. We also provide some management guidelines to help promote healthy plant-pollinator relationships in light of the potential variability in phenological shifts and the other threats these species face in natural areas.