Forecasting development of understory American beech after partial cutting in uneven-aged northern hardwood stands

American beech (Fagus grandifolia Ehrh.) in the understory of northern hardwood stands can interfere with the development of more desirable species such as sugar maple (Acer saccharum Marsh.). Yet, managers have had only limited methods for identifying stands where beech might dominate a new cohort. We examined five uneven-aged stands in New York State to determine the degree of influence that understory beech has on species development after a cutting treatment. No significant differences between stands were found, allowing us to develop a single model for evaluation. Understory beech was assessed using a species index value (SIV), which measures the proportion of stems, weighted by height, for a species on a milacre plot. We used a 5 x 5 transition matrix to compare pre- and post-cut beech importance levels. Stand-level trends showed an overall increase in the proportion of sample plots with higher levels of understory beech after cutting, with the likelihood of change on individual plots dependent on their pre-cut status. Plots with either no beech or very high levels of beech changed little after cutting, while beech was more likely to reach critical levels of dominance when pre-cut SIV was medium or higher. The transition matrix gives forest managers a means to forecast the probable level of future beech importance following cutting, based upon precursor conditions. (C) 2002 Elsevier Science B.V. All rights reserved.