Stand location variance as an indicator of disturbance regime in a monotypic Tsuga canadensis forest

Fishbowl

Disturbance regimes, which are critical components of forest ecosystems, are not well understood on small scales. In this paper I analyze tree cores to understand disturbance regimes through average growth release criteria using five sites within a Tsuga canadensis (Eastern hemlock) forest. This study asks the following questions: 1) Are disturbance regimes in the T. canadensis forest of UNDERC forest level or site-specific? 2) If they are site specific, is stand location a predictor of disturbance frequency? 3) Do site characteristics such as density and diameter at breast height (DBH) influence disturbance regimes? 4) Does T. canadensis release intensity correlate with disturbance size? I found that disturbance regimes in T. canadensis are site specific and depend greatly on forest geomorphology. Density and tree diameter may be weak predictors of disturbance regime. Additionally, the correlations revealed between high intensity release and low disturbance size suggests that T. canadensis may have a differential growth response to gap disturbances dependant on gap size. Though confined to one geographic location, this evidence suggests that T. canadensis disturbance regimes are complex, site specific, and predict growth strategies which ultimately influence forest structural complexity. The site specificity of T. canadensis disturbance regimes suggest that ecological and management studies, which often assume disturbance homogony, may miss important site differences.