FIRE DISTURBANCE PATTERNS AND FOREST AGE STRUCTURE

ABSTRACT. This paper investigates how the stability of forest age-distribution is related to the fire regimes. We start with the derivation of theoreticalnegative exponentialforest age-distribution, and use three models to explore the condition with which a stable age-distribution could be expected. The results suggested that a stable age-distribution could always be achieved as long as the forest age-specific mortality is constant over time, and the shape of a stable age-distribution is mainly determined by the forest age-specific mortality. However, the stability of forest age-distribution will be reduced when a small variation in the age-specific mortality is introduced. The simulation results of the possible patterns of the age-distribution under various fire regimes indicated that a variety of age-distribution curves could appear, including negative exponential and one or multiple peaks in the curves. The results suggested that a stable forest age-distribution might never be achieved if the forest landscape is subjected to large and irregular fire disturbances.