The USA National Phenology Network was established in 2007 to formalize standardized phenology monitoring across the country. The aims of the Network are to collect, store, and share phenology data and information to support scientific discovery, decision-making, an appreciation for phenology, and equitable engagement within the Network. To support these aims, the Network launched Nature’s Notebook, a rigorous platform for monitoring plant and animal phenology, in 2009. Since the launch of Nature’s Notebook, participants across the country have contributed over 28M phenology records. Participants range from backyard observers with an interest in nature to researchers and natural resource managers asking specific questions. We survey the breadth of studies and applied decisions that have utilized Nature’s Notebook and the consequent data. The dimensionality of the dataset maintained by the Network is a function of Nature’s Notebook users; this insight is key to shaping the Network’s future data collection activities.

Allergic respiratory disease affects millions of Americans, resulting in billions in medical expenses and lost productivity annually. Information regarding when pollen concentrations are increasing across the country is limited, diminishing the ability of health care professionals and individuals suffering from allergies and asthma to anticipate and manage their symptoms. The USA National Phenology Network, a science and monitoring network that collects, stores, and shares data and information products regarding the timing of seasonal events from across the country, offers a series of map and short-term forecast products that indicate the start of biological activity in the spring, based mainly on temperature conditions. In this study, we evaluate the potential for the Spring Indices to indicate the timing of the start and peak of airborne pollen concentrations by plant taxa, and by extension, their utility for predicting timing of increases in airborne allergenic pollen concentrations. We compared daily pollen counts collected at National Allergy Bureau (NAB) pollen counting stations across the country to the day of year the two Spring Indices – the Leaf Index and the Bloom Index – were met at those locations. In general, the Bloom Index exhibited stronger relationships with the timing of peaks in airborne pollen among the 36 plant taxa evaluated. This is likely because the Bloom Index occurs later in the season, closer to the timing of pollen peaks. However, relationships for the Leaf Index also demonstrate coherence (adj R2; ~ 0.5 +/- 0.15 [SD]). Relationships were generally strongest for Morus (mulberry), Populus (poplar), Fraxinus (ash), and Salix (willow), though the taxa best predicted by the Spring Indices varied by site. Strength of relationships did not vary appreciably across geography. Overall, the Spring Indices provide insight into seasonal pollen dynamics and have the potential to enhance springtime allergy management.