Mast in the Past: Predicting seed, fruit, and nut abundance since the Last Glacial Maximum using pollen-fecundity relationships
L. JENKINS , J. S. CLARK
Nicholas School of the Environment, Duke University, Durham, NC 27708, USA

Climate change poses devastating effects to food web biodiversity, yet its impacts on food availability for consumers remains understudied. Prehistoric food webs likely relied on high-quality resources of fruits, seeds, and nuts, but the influence of climate-induced forest biodiversity changes on ancient food webs is poorly understood. The Masting Inference and Forecasting (MASTIF) network synthesizes tree fecundity and habitat at a continental scale, allowing us to quantify historic tree fecundity. Here, we quantify spatio-temporal changes in seed supply in North America over the past 21,000 years using fecundity estimates, pollen counts, and paleoclimate reconstructions in a Generalized Joint Attribute Model (GJAM). Our model shows that large seed types (e.g., Quercus, Fagus, Carya ) have low sediment pollen to seed mass ratios (10-⁷ per kg of seed per Ha), while smaller seed types (e.g., Betula, Ulmus, Tsuga ) have higher ratios (10-³). Additionally, at four pollen sites in eastern North America, large-seeded species (e.g., Quercus, Fagus ) dominated mast availability, providing reliable food sources for consumers. Our results complement existing paleoecological studies, providing a direct link of forest regeneration and food supply to food webs. Thus, continued integration of pollen and fecundity data promises deeper insights into Pleistocene consumer communities.