Title: Seasonal Variation in Foliage Moisture Content of Pine Species at Acadia National Park, Maine (1995)
Authors: Ed McGuire and William Patterson, UMASS
Abstract: An important factor on whether or not an intense surface fire with cause torching of individual trees, which can lead to the development of a crown fire, is the moisture content of the foliage in the overstory trees. The moisture content of the foliage of pitch pine (Pinus rigida Mill), white pine (Pinus strobus L.) and red pine (Pinus resinosa Ait.) was examined at Acadia National Park, Maine. Second- and third-year needles declined in moisture content in the spring, reaching a low point in late-May and early-June. There was also a brief decline in mid-August, possibly due to drought conditions. First-year needles began at high moisture levels and declined throughout the summer. White pine usually had the lowest moisture content, pitch pine usually the highest. The highest potential for a surface fire of a given intensity to develop into a crown fire in pine stands at Acadia is during late-May and early-June. Further study should be conducted on the effects of drought on foliage moisture content in the summer and fall.