Effect of high forest and coppice regimes on the diameter distribution of Eucalyptus urophylla S. T. Blake stands

Eucalyptus plantations in Brazil can be assigned to one of two management regimes; high forest and coppice.The characterization of the diameter distribution in plantations under different management regimes is important for making decisions regarding the optimal regime, and helps quantify numerous wood products.The aim of this study was to evaluate the diameter distribution of a Eucalyptus urophylla S. T. Blake stand in the State of Minas Gerais, Brazil, under different management regimes and ages.Specific probabilistic density functions for forest area were fitted, and a probability distribution proposed in the literature was selected to evaluate the effects of management regime and age on diameter distribution.In total, 7,113 trees in stands of three, five, and seven years were assessed.A total of 3,396 trees grew under a high forest regime and 3,710 under a coppice regime.The fitted distribution curve presents negative asymmetry according to the stand age.Regarding differences between regimes and ages, the distribution curve for high forest results in a diametric distribution with larger trees and highest frequency (number of trees), when compared to coppice, for the three ages evaluated.The growth in diameter under the high forest regime stagnated before the age of seven years, suggesting earlier clearcuts to be performed.