Low-cost observations and experiments return a high value in plant phenology research.

Plant ecologists in the Anthropocene are tasked with documenting, interpreting, and predicting how plants respond to environmental change. Phenology, the timing of seasonal biological events including leaf-out, flowering, fruiting, and leaf senescence, is among the most visible and oft-recorded facets of plant ecology. Climate-driven shifts in plant phenology can alter reproductive success, interspecific competition, and trophic interactions.

Phenology models using herbarium specimens are only slightly improved by using finer-scale stages of reproduction.

Premise Of The Study: Herbarium specimens are increasingly used to study reproductive phenology. Here, we ask whether classifying reproduction into progressively finer-scale stages improves our understanding of the relationship between climate and reproductive phenology.

Methods: We evaluated herbarium specimens across eastern North America, classifying them into eight reproductive phenophases and four stages of leaf development.