Fire Regimes and Resultant Forest Structure in the Native Año Nuevo Monterey Pine (Pinus radiata) Forest, California

High severity fire has been reported to be the main disturbance agent that initiates seedling establishment for this species. To investigate the impacts of fire in this ecosystem, age structure and fire history data were collected from the native Año Nuevo Monterey pine forest near Santa Cruz, California. Stump cross-sections were removed from 10 randomly placed openings, and each was dated to determine tree age and fire history.

Average mean fire return intervals were 11.2–20.1 y. Fifty-one percent of the Monterey pine trees in all openings regenerated within 5 y of three mixed severity fires. This was well below the predicted value of 75% that was based on the literature and life history characteristic of Monterey pine. A fire in 1948 produced the largest Monterey pine regeneration episode, and this fire was verified by written records. Monterey pine forests are multi-aged and have a great amount of spatial heterogeneity, attributes common in mixed severity fire regimes. Monterey pine has morphological characteristics of a fire evader and fire resistor and may be more appropriately classified in an intermediate category.