Extreme weather events have strong but different impacts on plant and insect phenology

Abstract

The ability to explain and predict phenology across space, time and taxa has largely relied on annual average and seasonal climatic variables, ignoring the potential role of extreme weather events (EWEs) in regulating phenology. Yet, EWEs, which are predicted to increase in their severity and frequency with climate change, are also probably strong proximal phenology cues. Here we leveraged expansive community science resources to determine how EWEs affect plant flowering and insect flight beginning, termination and duration for 581 angiosperm species and 172 Lepidoptera across the contiguous United States. Our results provide evidence that plant and insect phenology is highly responsive to EWEs after accounting for seasonal and annual average climatic variables. The impact of EWEs on phenology varies depending on climatic context, and plant and insect responsiveness, while often similar, can be in the opposite directions. This suggests that EWEs may be key drivers of multitrophic phenological mismatches.