Title: A Vegetative Fuelbreak Protecting the Town of Bar Harbor, Maine – Acadia National Park, ME
Authors: Mark Herberger and William Patterson, UMASS
Abstract: The Bar Harbor Fire of 1947 burned a total of 17,188 acres (10,000 in Acadia National Park), killed three people, and destroyed 237 homes and the Jackson Laboratory on Mount Desert Island, Maine. The fire caused 23 million dollars in damages (1947 dollars). The volatile conifer forest that covered much of Mount Desert Island and contributed to the intensity of the fire was replaced by early successional species. Acadia National Park is evaluating the potential for using a deciduous fuelbreak to prevent a future fire from causing comparable damage. In this paper, I review literature related to the effective uses of fuelbreaks in general and report the results of a field study to evaluate the need for a fuelbreak on Mount Desert Island.
Previous studies suggest that a fuelbreak is most viable where, as at Acadia NP, large intense fires and human ignitions are the rule. Fuelbreaks are effective against intense crown fires if incorporated into an overall firefighting strategy. Tree species that are suitable for establishment on a vegetative fuelbreak include hardwoods that are fire resistant as a stand and as individuals and have low crown-fire potential.
I sampled 293 nested plots along the boundary between Acadia NP and the town of Bar Harbor. Cover types were determined for each point and were compared to 1979. During the past 18 years, conifers have increased in the overstory. Conifer regeneration was also sampled. I found that 9% of the plots sampled had conifer regeneration sufficient to form a future conifer overstory. Only 13% of all plots had hardwood regeneration sufficient to perpetuate present-day hardwood stands. If the corridor were to be treated to remove the conifer overstory and eliminate conifer regeneration with prescribed fire and/or mechanical means or encourage hardwood regeneration (vegetative reproduction or seedling establishment), I estimate that approximately 90% of the area [250 acre (101.2 ha)] will require treatment.