Abstract
Temperate understory plant species are at risk from climate change and anthropogenic threats that include increased deer herbivory1–3, habitat loss4, pollinator declines5 and mismatch6,7, and nutrient pollution8,9. Recent work suggests that spring ephemeral wildflowers may be at additional risk due to phenological mismatch with deciduous canopy trees10,11. The study of this dynamic, commonly referred to as “phenological escape”, and its sensitivity to spring temperature is limited to eastern North America10–16. Here, we use herbarium specimens to show that phenological sensitivity to spring temperature is remarkably conserved for understory wildflowers across North America, Europe, and Asia, but that canopy trees in North America are significantly more sensitive to spring temperature compared to in Asia and Europe. Our findings reveal that advancing tree phenology will lead to decreasing spring light windows in North America while spring light windows will be maintained or even increase in Asia and Europe in response to projected climate warming.
Competing Interest Statement
The authors have declared no competing interest.
