Hughes et al. 1999 predicted that secondary forests would reach total aboveground biomass levels equivalent to those of primary forest in the Los Tuxtlas Region after 73 years. Saldarriaga predicted that it would take 144-189 y for Venezuelan Amazon. Fearnside and Guimaraes (1996) estimated 100 yr in Brazilian Amazon. Differences in the interval necessary to reach levels of primary forest biomass likely are due to the period of land use prior to abandonment [Hughes 1999 #2251]. Although biomass may quickly recover structure and distribution of total aboveground biomass may be delayed longer as found by Hughes et al. 1999. Riley et al. (1997) used a model of 40 years.