We tested the hypothesis that recurrent fires may limit juniper expansion into southwestern semiarid grasslands and savannas.

Seven large fires at Wupatki National Monument, Arizona, burned 38% of the grasslands and dynamic savannas between 1995 and 2017.

Mortality of one-seed junipers (Juniperus monosperma) was >50% among smaller trees (<2 m tall), <40% among larger trees (>2 m tall), and 0% in trees >4 m tall.

Herbaceous vegetation recovered within 2 to 3 years postfire.

This suggests that fires may have limited juniper expansion historically and that fire may be an option for controlling juniper expansion and restoring grassland/savanna ecosystems today.