Prospects and challenges in assessing ecological groups of tree species during tropical forest succession

Since the days of Theophrastus (ca 373-287 BC), botanists have been classifying forest trees into different categories, based on a variety of criteria. Grouping species into different types is important for addressing both applied and theoretical questions, from selecting species for reforestation programs to understanding the maintenance of high species and functional diversity in tropical forests. Tree species are often grouped according to functional traits such as maximum growth rate, seed/seedling morphology, wood density, asymptotic height, longevity, pollination syndrome, seed dispersal syndrome, sexual system, response to fire, or re-sprouting potential. Alternatively, species have been grouped according to vital rates, such as rates of recruitment, mortality, and fecundity. A third method of classification is based on species’ size distributions within a given forest stand.