Climate Driven Oak Establishment at Helen Allison Savanna

Investigators: Susy Ziegler, Evan Larson, Julia Rauchfuss, Max Handler, and Grant Elliott

Pulses of tree recruitment at an oak savanna in east central Minnesota coincided with dry periods throughout the past 200 years. The dry climate and sandy, droughty soils might have limited the productivity of grasses and herbaceous species, thinning the ground cover and creating openings for oaks to develop. Fires might have provided a window of opportunity immediately after the burn for oak seedlings to become established with a pulse of nutrients and minimal competition from other plants.